JP2005080484A - Converting circuit, controller, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-phase to single-phase converting circuit capable of independently setting the voltage of a three-phase circuit and the voltage of a single-phase circuit, and in which the output current of the three-phase circuit is brought into equilibrium even if a load on the single-phase circuit is varied, and a controller and a control program for the power converting circuit. <P>SOLUTION: This power converting circuit 1 includes: a variable capacitance impedance circuit 5 connected between terminals U and V and capable of controlling the current between the terminals U and V; a variable inductance impedance circuit 6 connected between terminals V and W and capable of controlling the current between the terminals V and W; a first variable resistor circuit 7 connected in parallel to the variable capacitance impedance circuit 5 and capable of controlling the current between the terminals U and V; a second variable resistor circuit 8 connected in parallel to the variable capacitance impedance circuit 6 and capable of controlling the current between the terminals V and W; a first switch 17 capable of switching and connecting one terminal of a primary winding 13 of a first single-phase transformer 11; and a second switch 18 capable of switching and connecting one terminal of a primary winding 15 of a second single-phase transformer 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a three-phase / single-phase conversion circuit, a control device that performs current control by operating elements constituting the conversion circuit, and a control program.

  For example, in an AC electric railway that employs a commercial frequency single-phase AC system, a Scott connection transformer is used to reduce unbalance when receiving large-capacity single-phase power from a three-phase power system. However, since the Scott connection transformer is essentially a transformer for three-phase to two-phase conversion, the secondary voltage of the M-seat transformer and the T-seat transformer has a phase difference of 90 ° from each other. Even if the secondary windings of these M-seat and T-seat transformers are connected in series, they cannot be used as a single-phase three-wire system.

  In addition, the current on the three-phase side is balanced only when a single-phase load having the same load capacity and power factor is connected to each secondary side of both the M-seat and T-seat transformers. It is necessary to distribute equally to each secondary side of both M-seat and T-seat transformers. Therefore, the Scott connection transformer is practically difficult to use as an electric circuit for connecting a three-phase circuit and a single-phase circuit.

  On the other hand, a configuration called a Steinmetz circuit is known as a circuit that connects a three-phase circuit and a single-phase circuit. This Steinmetz circuit connects a capacitor between the U phase and V phase of a three-phase power supply (three-phase circuit) whose phase sequence is UVW, connects a reactor between the V phase and the W phase, and resistance between the W phase and the U phase. (Single-phase circuit) is connected. And the phase current which flows into a three-phase circuit can be made into an equilibrium current by setting each impedance of these capacitor | condenser, a reactor, and resistance to an appropriate value.

Since this Steinmetz circuit is essentially a circuit for three-phase to single-phase conversion, unlike a Scott connection transformer, it is not necessary to divide (distribute) a resistance that is a single-phase load into two. However, since the output voltage of the three-phase power source and the voltage applied to the resistor cannot be determined independently, the applicable circuits are very limited.
JP 2001-347355 A JP 2001-144703 A

  The problem to be solved is that, in a V-connection type electric circuit that performs three-phase to single-phase conversion, when the load amount on the single-phase circuit side changes, the output current on the three-phase circuit side is not correct in the conventional conversion circuit. It is a point that is balanced, it is a three-phase to single-phase conversion circuit, the voltage of the three-phase circuit and the voltage of the single-phase circuit can be set independently, and even if the load of the single-phase circuit changes An object of the present invention is to provide a conversion circuit in which the output current of the three-phase circuit is balanced, a control device for controlling the output current of the three-phase circuit of the conversion circuit to be balanced, and a control program.

  To achieve the above object, the present invention converts three-phase power into single-phase power by a first single-phase transformer and a second single-phase transformer, and each single-phase power is converted into a first single-phase circuit, And a Scott connection type conversion circuit for supplying to the second single-phase circuit, connected between terminals U and V, wherein the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits. And a variable capacitive impedance circuit capable of controlling the current between the terminals U and V according to the amount of active power consumption of the first single-phase circuit and the second single-phase circuit, and the terminals V and W The first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and the active power consumption of the first single-phase circuit and the second single-phase circuit A variable inductive impedance circuit capable of controlling the current between terminals V and W according to the size, Connected in parallel to the capacitive impedance circuit, and whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and the first single-phase circuit and the second single-phase circuit A first variable resistance circuit capable of controlling the current between the terminals U and V according to the amount of active power consumption, and the variable inductive impedance circuit connected in parallel, the first single-phase circuit and the second The current between terminals V and W can be controlled according to whether the single-phase circuit is a load circuit or a power supply circuit, and the amount of active power consumption of the first single-phase circuit and the second single-phase circuit. Depending on whether the second variable resistance circuit, the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, one terminal of the primary winding of the first single-phase transformer A first switcher that can be connected to a terminal V or a terminal W, and the first single phase Depending on whether the path and the second single-phase circuit are a load circuit or a power supply circuit, one terminal of the primary winding of the second single-phase transformer can be switched to a terminal U or a terminal V and connected. And a two-switching device.

  The variable capacitive impedance circuit is configured by connecting a variable capacitive impedance and a switching element capable of turning on / off current in series, and the variable inductive impedance circuit turns on variable inductive impedance and current. The first variable resistance circuit and the second variable resistance circuit are configured by connecting a resistance and a switching element capable of turning on / off a current in series. Is done.

  In order to achieve the above object, the present invention provides a control device for controlling the conversion circuit, wherein the first single-phase circuit detects whether or not active power is consumed or supplied. Phase circuit state detection means, second single phase circuit state detection means for detecting whether the second single phase circuit is consuming or supplying active power, the first single phase circuit state detection means, and the first Circuit switching means for outputting a circuit switching signal for switching the connection between the first switch and the second switch according to the detection result of the two single-phase circuit state detection means, the first single-phase circuit state detection means, and the Control switching for outputting a control signal for controlling the variable capacitive impedance circuit, the variable inductive impedance circuit, the first variable resistance circuit, and the second variable resistance circuit in accordance with a detection result with the second single-phase circuit state detection means. means Characterized in that it comprises a.

  Further, the control switching means is configured to assume that a single-phase load is connected to the first single-phase transformer when it is detected that the first single-phase circuit is consuming active power. A first load active power detecting means for detecting an active power amount of one single-phase circuit; and when the second single-phase circuit detects that the second single-phase circuit is consuming active power, Assuming that a single-phase load is connected, second load active power detection means for detecting the active power amount of the second single-phase circuit, and the variable capacitive impedance circuit and the variable from the detected both active power amounts Compensation amount calculating means for calculating the reactive power amount compensated by the inductive impedance circuit and the effective power amount compensated by the first variable resistance circuit and the second variable resistance circuit, and the variable amount from the calculated power compensation amounts. Capacitive impedance circuit, and front Inter-UV firing angle determining means for determining the firing angle of the switching elements connected in series to the first variable resistance circuit, the variable inductive impedance circuit from the calculated power compensation amounts, and the second variable VW firing angle determining means for determining the firing angle of the switching elements connected in series to the resistance circuit, and voltage detecting means for detecting the respective line voltages between the terminals UV and VW, respectively. And the variable capacitive impedance at a firing angle determined by the UV firing angle determining means with respect to the detected line voltage phase between the terminals UV. A line voltage level between the UV pulse control means for outputting a control signal for firing the circuit and the switching element connected in series to the first variable resistance circuit, and the detected terminal VW VW for outputting a control signal for igniting the switching element connected in series to the variable inductive impedance circuit and the second variable resistance circuit at the firing angle determined by the VW firing angle determining means. Inter-pulse control means.

  Further, the control switching means is configured to assume that a single-phase power source is connected to the first single-phase transformer when it is detected that the first single-phase circuit supplies active power. A first power source active power detecting means for detecting an active power amount of one single phase circuit; and when the second single phase circuit detects that the second single phase circuit is consuming active power, Assuming that a single-phase power source is connected, a second power source active power detecting means for detecting an active power amount of the second single-phase circuit is provided.

  In order to achieve the above object, the present invention provides a control program that operates on a computer that controls the conversion circuit, and supplies the computer with whether the first single-phase circuit is consuming active power. First single-phase circuit state detecting means for detecting whether the second single-phase circuit is consuming or supplying active power, and the first single-phase circuit state detecting means for detecting whether the second single-phase circuit is consuming or supplying active power. Circuit switching means for outputting a circuit switching signal for switching the connection between the first switch and the second switch according to the detection results of the phase circuit state detection means and the second single-phase circuit state detection means, and the first According to the detection results of the single-phase circuit state detection means and the second single-phase circuit state detection means, the variable capacitive impedance circuit, the variable inductive impedance circuit, the first variable resistance circuit, and the second variable resistance Characterized in that to function as the control switching means for outputting a control signal for controlling the circuit.

  In addition, the control program assumes that a single-phase load is connected to the first single-phase transformer when the computer detects that the first single-phase circuit is consuming active power. First load active power detecting means for detecting the amount of active power of the first single-phase circuit; and the second single-phase transformer when it is detected that the second single-phase circuit is consuming active power. Is connected to a single-phase load, the second load active power detecting means for detecting the active power amount of the second single-phase circuit, and the variable capacitive impedance circuit from the detected both active power amounts, Compensation amount calculation means for calculating the reactive power amount compensated by the variable inductive impedance circuit and the active power amount compensated by the first variable resistance circuit and the second variable resistance circuit, and the calculated power compensation amounts Said variable capacitive impeder An inter-UV ignition angle determining means for determining an ignition angle of a switching element connected in series to each of the first variable resistance circuit, and the variable inductive impedance circuit from each calculated power compensation amount, And VW firing angle determining means for determining the firing angle of the switching elements connected in series to the second variable resistance circuit, and voltage detection for detecting the respective line voltages between the terminals UV and VW. Means, phase detection means for detecting the phase of each detected line voltage, and the ignition angle determined by the UV ignition angle determination means for the detected line voltage phase between the terminals UV, Pulse control means between UV for outputting a control signal for firing a switching element connected in series to the variable capacitive impedance circuit and the first variable resistance circuit, and a detected terminal A switching element connected in series to the variable inductive impedance circuit and the second variable resistance circuit is ignited at an ignition angle determined by a VW ignition angle determining means with respect to a line voltage phase between W It functions as pulse control means between VWs that outputs a control signal.

  Further, the control program is configured such that when the computer detects that the first single-phase circuit supplies active power, a single-phase power source is connected to the first single-phase transformer. First power source active power detection means for detecting the amount of active power of the first single phase circuit; and when the second single phase circuit detects that the second single phase circuit is consuming active power, the second single phase transformer Is connected to a single-phase power source, and functions as a second power source active power detection means for detecting the active power amount of the second single-phase circuit.

  According to the present invention, the voltage of the three-phase circuit and the voltage of the single-phase circuit can be set independently, and the output current of the three-phase circuit is balanced even if the load of the single-phase circuit changes. As a power conversion facility for AC electric railways that adopt a commercial frequency single-phase AC system, or for converting three-phase power generated by a distributed power source to a single-phase load such as a lighting device, etc. For example, it can be applied to a wide range of fields in order to reduce or eliminate the unbalance on the three-phase side in applications where power is converted from a three-phase to a single-phase circuit.

  An embodiment of the present invention will be described with reference to FIGS.

  First, the configuration of the conversion circuit 1 in the present embodiment will be described. FIG. 1 shows an electrical configuration of a conversion circuit 1 used when connecting a single-phase circuit to a three-phase circuit. The conversion circuit 1 converts three-phase power generated by a three-phase power source 2 (corresponding to a three-phase circuit) into single-phase power and supplies it to the first single-phase circuit 3 and the second single-phase circuit 4. To do. The three-phase power source 2 is a power source that outputs a three-phase voltage (for example, 400 V system) by a distributed power source or the like.

  A variable capacitive impedance circuit 5 and a variable resistance circuit 7 are connected in parallel between the terminals UV of the conversion circuit 1, and a variable inductive impedance circuit 6 and a variable resistance circuit 8 are connected in parallel between the terminals VW. .

  The terminal U is connected to the terminal a of the first switch 17 and the terminal W is connected to the terminal d of the second switch 18. The terminal V is connected to the terminal b of the first switch 17 and the terminal e of the second switch 18. One end of the primary winding 13 of the first single-phase transformer 11 is connected to the terminal U, the other end is connected to the terminal f of the second switch 18, and the primary winding 15 of the second single-phase transformer 12. One end is connected to the terminal W, and the other end is connected to the terminal c of the first switch 17.

  The terminals U, V, and W are connected to a three-phase power source 2 that outputs a three-phase voltage with a phase sequence of UVW, and the secondary winding 14 of the first single-phase transformer 11 has a first single-phase load. 9 or the first single-phase power supply 9 and the second single-phase load 10 or the second single-phase power supply 10 is connected to the secondary winding 16 of the second single-phase transformer 12.

  As shown in FIG. 2, the variable capacitive impedance circuit 5 includes a capacitive impedance circuit 21 and a current control circuit 22 connected in series, and the variable inductive impedance circuit 6 includes an inductive impedance circuit 23. And the current control circuit 24 are connected in series. The first variable resistance circuit 7 is configured by connecting a resistor 25 and a current control circuit 26 in series, and the second variable resistance circuit 8 is configured by connecting a resistor 27 and a current control circuit 28 in series. . Each of the current control circuits 22, 24, 26, 28 includes a thyristor, and a control signal output from a control switching unit 35 of the control device 3 described later is a signal for driving (igniting) the gate of the thyristor. It is.

  The current supplied to the UVW from the three-phase power source 2 is IV, IU, IW, the current flowing through the variable capacitive impedance circuit 5 is IC, the current flowing through the variable inductive impedance circuit 6 is IL, and the first variable resistance circuit The current flowing through 7 is IRuv, and the current flowing through the second variable resistance circuit 8 is IRvw.

  Also, the current flowing through the primary winding 13 of the first single-phase transformer 11 is Ipm, the current flowing through the secondary winding 14 of the first single-phase transformer 11 is Ips, and the primary winding of the second single-phase transformer 12 The current flowing through 15 is Ism, and the current flowing through the secondary winding 16 of the second single-phase transformer 12 is Iss.

  FIG. 3 shows a functional configuration of the control device 31 that controls the first switch 17, the second switch 18, and the current control circuits 22, 24, 26, 28 of the conversion circuit 1. As shown in FIG. 3, the control device 31 in the present embodiment includes a first single-phase circuit state detection unit 32, a second single-phase circuit state detection unit 33, a circuit switching unit 34, and a control switching unit 35. The

  The first single-phase circuit state detection unit 32 detects whether or not the single-phase device of the first single-phase circuit 3 is consuming or supplying active power using a general method for detecting active power of an electric circuit. If it is, the flag value “0” is controlled with the circuit switching unit 34 if the single-phase device is a load circuit, and if it is supplied, the flag value “1” is controlled with the circuit switching unit 34. A function of outputting to the switching unit 35 is provided.

  Further, the second single-phase circuit state detection unit 33 detects whether the single-phase device of the second single-phase circuit 4 is consuming or supplying active power by a general method for detecting the active power of an electric circuit. In the case of consumption, the flag value “0” is assumed that the single-phase device is a load circuit, and in the case of supply, the flag value “1” is assumed that the single-phase device is a power supply circuit. And the control switching unit 35.

  The detection method of the effective power of this general electric circuit is, for example, a method of obtaining effective power from the voltage and current detected by the voltage detector and the current detector, or a method of detecting with an wattmeter.

また、制御切替部３５は、第１単相回路状態検出部３２と第２単相回路状態検出部３３とから供給されるフラグ値に従って、制御モードを切り替え、各電流制御回路２２，２４，２６，２８を制御する制御信号を出力する機能を有する。フラグ値と制御切替部３５の制御モードとの対応を表２に示す。なお、各制御モードの詳細については後述する。

次に、制御装置３１の概略動作について、図４のフローチャートに基づいて説明する。 The circuit switching unit 34 connects the first switch 17 and the second switch 18 in accordance with the flag values supplied from the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33. It has a function of outputting a circuit switching signal for switching. Table 1 shows the correspondence between the flag value and the connection of each terminal of the first switch 17 and the second switch 18.

In addition, the control switching unit 35 switches the control mode according to the flag values supplied from the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33, and each current control circuit 22, 24, 26 , 28 has a function of outputting control signals. Table 2 shows the correspondence between the flag value and the control mode of the control switching unit 35. Details of each control mode will be described later.

Next, a schematic operation of the control device 31 will be described based on the flowchart of FIG.

  When the control device 31 starts controlling the conversion circuit 1, the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33 are respectively connected to the first single-phase circuit 3 and the second single-phase circuit 4. It is detected whether the phase device is consuming or supplying active power (step S01), and it is determined whether the single-phase device is a load circuit (step S02).

  When the single-phase device is a load circuit, each of the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33 sets the flag value to “0” (step S03). If the phase device is not a load circuit, the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33 each set the flag value to “1” (step S04), and the circuit switching unit 34 The flag value is output to the control switching unit 35.

  When the flag value is supplied from the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33, the circuit switching unit 34 sets each flag value according to the correspondence between the flag values shown in Table 1 and the connection of each terminal. The connection terminals of the switching devices 17 and 18 are determined, and a circuit switching signal for switching the connection between the first switching device 17 and the second switching device 18 is output to the first switching device 17 and the second switching device 18. When the flag value is supplied from the first single-phase circuit state detection unit 32 and the second single-phase circuit state detection unit 33, the control switching unit 35 follows the correspondence between the flag value and the control mode shown in Table 2. The control mode of each current control circuit 22, 24, 26, 28 of the conversion circuit 1 is determined (step S05).

  When the control switching unit 35 determines the control mode, the control switching unit 35 shifts to each control mode (step S06) and outputs a control signal for controlling each current control circuit 22, 24, 26, 28.

  Thus, in the control device 31, the first single-phase circuit 3 and the second single-phase circuit 4 are both single-phase loads, or the first single-phase circuit 3 is a single-phase load and the second single-phase circuit 4 is a single-phase load. Even if the first single-phase circuit 3 is a single-phase power supply and the second single-phase circuit 4 is changed to a single-phase load state, the conversion circuit 1 so that the output current of the three-phase power supply 2 is balanced To control.

  Hereinafter, the operation of the control switching unit 35 will be described in accordance with the substance of the single-phase device in each mode.

<Control mode: MODE-1, when the active power consumption of the first single-phase load and the second single-phase load are equal>
Both the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase load circuits (hereinafter referred to as a first single-phase load 9 and a second single-phase load 10 respectively), and the first When the active power consumptions of the single-phase load 9 and the second single-phase load 10 are equal, the control switching unit 35a has a first load active power detection unit 41 and a second load active power detection unit 42 as shown in FIG. , Compensation amount calculation unit 43, UV firing angle determination unit 44, VW firing angle determination unit 45, voltage detection unit 46, phase detection unit 47, UV pulse control unit 48, and VW pulse control unit 49. It consists of functional blocks and operates.

  The first load active power detection unit 41 has a function of detecting the active power amount of the first single-phase load 9 of the first single-phase circuit 3 by a general method for detecting the active power of the electric circuit, and the second load The active power detection unit 42 has a function of detecting the active power amount of the second single-phase load 10 of the second single-phase circuit 4 by a general method for detecting the active power of an electric circuit.

  The detection method of the effective power of this general electric circuit is, for example, a method of obtaining effective power from the voltage and current detected by the voltage detector and the current detector, or a method of detecting with an wattmeter.

  Further, the compensation amount calculation unit 43 calculates the reactive power amount to be compensated by the variable capacitive impedance circuit 5 and the variable inductive impedance circuit 6 from the detected active power amount of the first single-phase load 9 and the second single-phase load 10. The first variable resistance circuit 7 and the second variable resistance circuit 8 have a function of calculating an effective power amount to be compensated.

  Further, the inter-UV firing angle determination unit 44 is connected to the variable capacitive impedance circuit 5 and the first variable resistance circuit 7 in series from the power compensation amount calculated by the compensation amount calculation unit 43, respectively. It has a function of determining 26 firing angles.

  Further, the VW firing angle determination unit 45 is connected to the variable inductive impedance circuit 6 and the second variable resistance circuit 8 in series from the power compensation amount calculated by the compensation amount calculation unit 43, respectively. It has a function of determining 28 firing angles.

  The voltage detection unit 46 has a function of detecting the line voltage between the terminal U and the terminal V and between the terminal V and the terminal W, and the phase detection unit 47 is connected between the lines detected by the voltage detection unit 46. It has a function of detecting the phase of voltage.

  Further, the inter-UV pulse control unit 48 uses the ignition angle determined by the inter-UV ignition angle determination unit 44 with respect to the line voltage phase between the terminals UV detected by the phase detection unit 47, and the variable capacitive impedance circuit 5. And has a function of outputting a control signal for starting the thyristor constituting the current control circuits 22 and 26 connected in series to the first variable resistance circuit 7.

  Further, the inter-VW pulse control unit 49 has the firing angle determined by the inter-VW firing angle determination unit 45 with respect to the line voltage phase between the terminals VW detected by the phase detection unit 47, and the variable inductive impedance circuit 6 And a function of outputting a control signal for igniting the thyristors constituting the current control circuits 24 and 28 connected in series to the second variable resistance circuit 8.

  Next, the operation of the control switching unit 35a will be described based on the flowchart of FIG.

  When the control device 31 starts the control of the conversion circuit 1 with MODE-1, the first load active power detection unit 41 determines the active power amount of the first single-phase load 9 by a general method for detecting the active power of the electric circuit. It detects (step S11). Similarly, the second load active power detection unit 42 detects the effective power amount of the second single-phase load 10 by a general method for detecting active power of an electric circuit (step S12).

  When the respective active power amounts detected by the first load active power detection unit 41 and the second load active power detection unit 42 are supplied to the compensation amount calculation unit 43, the compensation amount calculation unit 43 first selects the first single-phase load 9 and The effective power consumption of the second single-phase load 10 is compared.

  As a result of the comparison, when the active power consumptions of the first single-phase load 9 and the second single-phase load 10 are equal, the compensation amount calculation unit 43 is connected to the terminal according to the following equations (1), (2), and (3). The power compensation amount Quv in the variable capacitive impedance circuit 5 between UV, the power compensation amount Qvw in the variable inductive impedance circuit 6 between the terminals VW, the current IRuv of the first variable resistance circuit 7 between the terminals UV, The current IRvw of the second variable resistance circuit 8 between the terminals VW is calculated (step S13). Here, the rated line voltage of the three-phase power source 2 is E, and the active power of both single-phase loads is PL.

≪Number 1≫
Ipm = Ism = PL / E (1)
Quv = Qvw = E x Ipm x 1/3 ^1/2 (2)
IRuv = IRvw = 0 (3)
The compensation amount calculation unit 43 calculates each power compensation amount according to the above formula, and supplies Quv and IRuv to the UV firing angle determination unit, and supplies Qvw and IRvw to the VW firing angle determination unit.

なお、Q1〜Qn、およびIR1〜IRnの実際の値は、回路構成に従う。 As shown in Table 3, Table 4, Table 5, and Table 6, the inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are preliminarily set to the firing angle α with respect to the power compensation amount Q and between the terminals UV. A data table is recorded in which the correspondence of the firing angle α to the resistance current value between the terminals VW is recorded. The inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are based on the compensation amount calculating unit 43. When each power compensation amount is supplied, the firing angles αQuv and αQvw for the supplied Quv and Qvw are set (step S14), the firing angles αRuv and αRvw for IRuv and IRvw are set (step S15), and UV is set. This is supplied to the inter-pulse controller 48 and the inter-VW pulse controller 49, respectively. Here, since the active power consumptions of the first single-phase load 9 and the second single-phase load 10 are equal, the inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 determine the firing angles αRuv, αRvw. Are each set to 90 degrees.

The actual values of Q1 to Qn and IR1 to IRn depend on the circuit configuration.

  Further, the voltage detection unit 46 detects the line voltage instantaneous value euv between the terminals UV by a general electric circuit voltage detection method (step S16), and the detected line voltage instantaneous value euv to the phase detection unit 47. Supply.

  The phase detection unit 47 detects the line voltage phase θuv between the terminals UV using the phase detection device (PLL) or the like from the line voltage instantaneous value euv supplied from the voltage detection unit 46, and the following equation (4) ), The line voltage phase θvw between the terminals VW is calculated (step S17), and θuv is supplied to the UV pulse control unit 48 and θvw is supplied to the VW pulse control unit 49.

≪Number 2≫
θvw = θuv-120 ° (4)
The inter-UV pulse control unit 48 determines whether or not αQuv supplied from the inter-UV firing angle determination unit 44 matches θuv supplied from the phase detection unit 47 (step S18), and αQuv and θuv match. If it is determined, the UV pulse control unit 48 outputs a control signal for firing the thyristor constituting the current control circuit 22 (step S19).

  Further, the inter-VW pulse control unit 49 determines whether αQvw supplied from the inter-VW firing angle determination unit 45 matches θvw supplied from the phase detection unit 47 (step S20), and αQvw and θvw Are determined to match, the inter-VW pulse controller 49 outputs a control signal for firing the thyristor constituting the current control circuit 24 (step S21).

  In addition, when the active power consumption of the 1st single phase load 9 and the 2nd single phase load 10 is equal, it is between UW so that the 1st variable resistance circuit 7 and the 2nd variable resistance circuit 8 may be in a non-conduction state. Since the firing angle determination unit and the VW firing angle determination unit 45 set αRuv and αRvw to 90 degrees, respectively, the inter-UV pulse control unit 48 determines the current of the first variable resistance circuit 7 between the terminals UV. A control signal for starting the thyristor constituting the control circuit 26 is not output (step S22). Similarly, the inter-VW pulse control unit 49 does not output a control signal for firing the thyristor constituting the current control circuit 28 of the second variable resistance circuit 8 between the terminals VW (step S23).

  FIG. 7 shows a voltage vector (a) and a current vector (b) when the active power consumptions of the first single-phase load 9 and the second single-phase load 10 are equal. The main vector symbols used in the following description are as follows, and the positive direction (reference direction) is as shown in FIG. In the following description, for convenience, each symbol is used not only for a vector but also for indicating a scalar quantity (that is, a voltage value and a current value).

Eu ... Phase voltage vector of U phase of three-phase power supply 2
Ev ... Phase voltage vector of V phase of three-phase power supply 2
Ew ... Phase voltage vector of the W phase of the three-phase power supply 2
Euv ... Line voltage vector between U phase and V phase of three-phase power supply 2
Evw ... Line voltage vector between V phase and W phase of three-phase power supply 2
Ewu ... Line voltage vector between W phase and U phase of three-phase power supply 2
Iu ... U-phase current vector of three-phase power supply 2
Iv ... V-phase current vector of three-phase power supply 2
Iw ... W-phase current vector of the three-phase power supply 2
IC: Current vector of variable capacitive impedance circuit 5 between U phase and V phase of three-phase power supply 2
IL: Current vector of variable inductive impedance circuit 6 between V phase and W phase of three-phase power supply 2
IRuv: Current vector of the first variable resistance circuit 7 between the U phase and V phase of the three-phase power supply 2
IRvw: Current vector of the second variable resistance circuit 8 between the V-phase and W-phase of the three-phase power supply 2
Ipm ... Current vector of the primary winding of the first single-phase transformer 11
Ism: Current vector of the primary winding of the second single-phase transformer 12 Both the devices connected to the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase loads, and both load amounts are the same. In the case of a quantity, as shown in FIG. 7B, the current vector IC of the variable capacitive impedance circuit 5 connected between the terminals UV becomes a vector advanced by 90 ° with respect to the voltage vector Euv, and between the terminals VW. The current vector IL of the variable inductive impedance circuit 6 connected to is a vector delayed by 90 ° with respect to the voltage vector Evw.

  The U-phase, V-phase, and W-phase current vectors Iu, Iv, and Iw are determined by the following equations (5), (6), and (7), respectively.

<< Equation 3 >>
Iu = Ipm-IC (5)
Iv = Ism-Ipm + IC-IL (6)
Iw = IL-Ism (7)
The magnitudes of the currents IRuv and IRvw of the first variable resistance circuit 7 and the second variable resistance circuit 8 are respectively determined by the following formulas (8) and (9).

<< Equation 4 >>
IRuv = 0 (8)
IRvw = 0 (9)
When the impedances 5, 6, 7, and 8 are controlled as shown in steps S11 to S23, the magnitudes of the current vectors Iu, Iv, and Iw shown in FIG. Respectively coincide with the directions of the phase voltage vectors Eu, Ev, Ew. That is, the power factor of the three-phase power source 2 is 1, and the current of the three-phase power source 2 is a complete balanced three-phase current.

  Therefore, when both the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase loads and the active power consumptions of the first single-phase load 9 and the second single-phase load 10 are equal, the load amount Even if the power factor changes within the range of power factor 1, the output current of the three-phase power source 2 can be controlled to be balanced.

<Control mode: MODE-1, when the effective power consumption of the first single-phase load is greater than the effective power consumption of the second single-phase load>
Both the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase load circuits, and the effective power consumption of the first single-phase load 9 is the effective power consumption of the second single-phase load 10. When larger than the amount, the control switching unit 35, as shown in FIG. 5, the first load active power detection unit 41, the second load active power detection unit 42, the compensation amount calculation unit 43, the inter-UV firing angle determination unit 44. The inter-VW firing angle determining unit 45, the voltage detecting unit 46, the phase detecting unit 47, the UV pulse control unit 48, and the inter-VW pulse control unit 49 are configured and operated. A description of each functional block is omitted.

  Next, the operation of the control switching unit 35a will be described based on the flowchart of FIG.

  When the control device 31 starts the control of the conversion circuit 1 with MODE-1, the first load active power detection unit 41 determines the active power amount of the first single-phase load 9 by a general method for detecting the active power of the electric circuit. It detects (step S31). Similarly, the second load active power detection unit 42 detects the effective power amount of the second single-phase load 10 by a general method for detecting active power of an electric circuit (step S32).

  When the respective active power amounts detected by the first load active power detection unit 41 and the second load active power detection unit 42 are supplied to the compensation amount calculation unit 43, the compensation amount calculation unit 43 first selects the first single-phase load 9 and The effective power consumption of the second single-phase load 10 is compared.

  If the effective power consumption of the first single-phase load 9 is greater than the effective power consumption of the second single-phase load 10 as a result of the comparison, the following formulas (10), (11), (12), (13), (14) ), The compensation amount calculation unit 43 calculates the power compensation amount Quv in the variable capacitive impedance circuit 5 between the terminals UV, the power compensation amount Qvw in the variable inductive impedance circuit 6 between the terminals VW, and between the terminals UV. The current IRuv of the first variable resistance circuit 7 and the current IRvw of the second variable resistance circuit 8 between the terminals VW are calculated (step S33). Here, the rated line voltage of the three-phase power source 2 is E, the active power of the first single-phase load 9 is PL1, and the active power of the second single-phase load 10 is PL2.

≪Number 5≫
Ipm = PL1 / E (10)
Ism = PL2 / E (11)
Quv = Qvw = E x Ipm x 1/3 ^1/2 (12)
IRuv = 0 (13)
IRvw = (PL1-PL2) / E = Ipm-Ism (14)
The compensation amount calculation unit 43 calculates each power compensation amount according to the above formula, and supplies Quv and IRuv to the UV firing angle determination unit, and supplies Qvw and IRvw to the VW firing angle determination unit.

  As shown in Table 3, Table 4, Table 5, and Table 6, the inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are preliminarily set to the firing angle α with respect to the power compensation amount Q and between the terminals UV. A data table is recorded in which the correspondence of the firing angle α to the resistance current value between the terminals VW is recorded. The inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are based on the compensation amount calculating unit 43. When each power compensation amount is supplied, the firing angles αQuv and αQvw for the supplied Quv and Qvw are set (step S34), the firing angles αRuv and αRvw for IRuv and IRvw are set (step S35), and UV is set. This is supplied to the inter-pulse controller 48 and the inter-VW pulse controller 49, respectively. Here, since the effective power consumption of the first single-phase load 9 is larger than the effective power consumption of the second single-phase load 10, the inter-UV firing angle determination unit 44 sets the firing angle αRuv to 90 degrees. (Step S36).

  Further, the voltage detection unit 46 detects the line voltage instantaneous value euv between the terminals UV by a general electric circuit voltage detection method (step S37), and the detected line voltage instantaneous value euv to the phase detection unit 47. Supply.

  The phase detection unit 47 detects the line voltage phase θuv between the terminals UV from the instantaneous line voltage euv supplied from the voltage detection unit 46 using a phase detection device (PLL) or the like, and according to Equation (4). The line voltage phase θvw between the terminals VW is calculated (step S38), and θuv is supplied to the UV pulse controller 48 and θvw is supplied to the VW pulse controller 49.

  The inter-UV pulse control unit 48 determines whether αQuv supplied from the inter-UV firing angle determination unit 44 matches θuv supplied from the phase detection unit 47 (step S39), and αQuv and θuv match. If it is determined, the UV pulse controller 48 outputs a control signal for firing the thyristor constituting the current control circuit 22 (step S40).

  Further, the inter-VW pulse control unit 49 determines whether αQvw and αRvw supplied from the inter-VW firing angle determination unit 45 coincide with θvw supplied from the phase detection unit 47 (step S41), and αQvw And θvw are determined to match, the inter-VW pulse controller 49 outputs a control signal for firing the thyristor constituting the current control circuit 24 (step S42).

  Further, the inter-VW pulse control unit 49 determines whether αRvw supplied from the inter-VW firing angle determination unit 45 matches θvw supplied from the phase detection unit 47 (step S42), and αRvw and θvw are determined. Are determined to match, the inter-VW pulse controller 49 outputs a control signal for firing the thyristor constituting the current control circuit 28 (step S44).

  When the effective power consumption of the first single-phase load 9 is larger than the effective power consumption of the second single-phase load 10, the UW firing angle is set so that the first variable resistance circuit 7 becomes non-conductive. Since the determination unit sets αRuv to 90 degrees, the UV pulse control unit 48 outputs a control signal for starting the thyristor constituting the current control circuit 26 of the first variable resistance circuit 7 between the terminals UV. No (step S45).

  FIG. 9 shows a voltage vector (a) and a current vector (b) when the effective power consumption of the first single-phase load 9 is larger than the effective power consumption of the second single-phase load 10.

  The devices connected to the first single-phase circuit 3 and the second single-phase circuit 4 are both single-phase loads, and the effective power consumption of the first single-phase load 9 is the effective power consumption of the second single-phase load 10. When the amount is larger than the amount, as shown in FIG. 9B, the current vector IRvw of the second variable resistance circuit 8 connected between the terminals VW is a vector in phase with the voltage vector Evw.

  The U-phase, V-phase, and W-phase current vectors Iu, Iv, and Iw are respectively determined by the following equations (15), (16), and (17).

<< Equation 6 >>
Iu = Ipm-IC (15)
Iv = Ism-Ipm + IC-IL + IRvw (16)
Iw = IL-Ism-IRvw (17)
The magnitudes of the currents IRuv and IRvw of the first variable resistance circuit 7 and the second variable resistance circuit 8 are determined by the following formulas (18) and (19).

<< Equation 7 >>
IRuv = 0 (18)
IRvw = Ipm-Ism (19)
When the impedances 5, 6, 7, and 8 are controlled as shown in steps S31 to S45, the magnitudes of the current vectors Iu, Iv, and Iw shown in FIG. Respectively coincide with the directions of the phase voltage vectors Eu, Ev, Ew. That is, the power factor of the three-phase power source 2 is 1, and the current of the three-phase power source 2 is a complete balanced three-phase current.

  Accordingly, both the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase loads, and the effective power consumption of the first single-phase load 9 is greater than the effective power consumption of the second single-phase load 10. When the load is large, the output current of the three-phase power supply 2 can be controlled in a balanced manner even if the load amount changes in the range of the power factor 1.

<Control mode: MODE-1, when the effective power consumption of the first single-phase load is smaller than the effective power consumption of the second single-phase load>
Both the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase load circuits, and the effective power consumption of the first single-phase load 9 is the effective power consumption of the second single-phase load 10. If smaller than the amount, the control switching unit 35, as shown in FIG. 5, the first load active power detection unit 41, the second load active power detection unit 42, the compensation amount calculation unit 43, the inter-UV firing angle determination unit 44. The inter-VW firing angle determining unit 45, the voltage detecting unit 46, the phase detecting unit 47, the UV pulse control unit 48, and the inter-VW pulse control unit 49 are configured and operated. A description of each functional block is omitted.

  Next, the operation of the control switching unit 35a will be described based on the flowchart of FIG.

  When the control device 31 starts the control of the conversion circuit 1 with MODE-1, the first load active power detection unit 41 determines the active power amount of the first single-phase load 9 by a general method for detecting the active power of the electric circuit. Detection is performed (step S51). Similarly, the second load active power detection unit 42 detects the amount of active power of the second single-phase load 10 by a general method for detecting active power of an electric circuit (step S52).

  When the respective active power amounts detected by the first load active power detection unit 41 and the second load active power detection unit 42 are supplied to the compensation amount calculation unit 43, the compensation amount calculation unit 43 first selects the first single-phase load 9 and The effective power consumption of the second single-phase load 10 is compared.

  If the effective power consumption of the first single-phase load 9 is smaller than the effective power consumption of the second single-phase load 10 as a result of the comparison, the following mathematical formulas (20) (21) (22) (23) (24 ), The compensation amount calculation unit 43 calculates the power compensation amount Quv in the variable capacitive impedance circuit 5 between the terminals UV, the power compensation amount Qvw in the variable inductive impedance circuit 6 between the terminals VW, and between the terminals UV. The current IRuv of the first variable resistance circuit 7 and the current IRvw of the second variable resistance circuit 8 between the terminals VW are calculated (step S53). Here, the rated line voltage of the three-phase power source 2 is E, the active power of the first single-phase load 9 is PL1, and the active power of the second single-phase load 10 is PL2.

<< Equation 8 >>
Ipm = PL1 / E (20)
Ism = PL2 / E (21)
Quv = Qvw = E x Ipm x 1/3 ^1/2 (22)
IRuv = (PL1-PL2) / E = Ipm-Ism (23)
IRvw = 0 (24)
The compensation amount calculation unit 43 calculates each power compensation amount according to the above formula, and supplies Quv and IRuv to the UV firing angle determination unit, and supplies Qvw and IRvw to the VW firing angle determination unit.

  As shown in Table 3, Table 4, Table 5, and Table 6, the inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are preliminarily set to the firing angle α with respect to the power compensation amount Q and between the terminals UV. A data table is recorded in which the correspondence of the firing angle α to the resistance current value between the terminals VW is recorded. The inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 are based on the compensation amount calculating unit 43. When each power compensation amount is supplied, the firing angles αQuv and αQvw for the supplied Quv and Qvw are set (step S54), the firing angles αRuv and αRvw for IRuv and IRvw are set (step S55), and UV is set. This is supplied to the inter-pulse controller 48 and the inter-VW pulse controller 49, respectively. Here, since the effective power consumption of the first single-phase load 9 is smaller than the effective power consumption of the second single-phase load 10, the inter-VW firing angle determination unit 45 sets the firing angle αRvw to 90 degrees. (Step S56).

  The voltage detection unit 46 detects the line voltage instantaneous value euv between the terminals UV by a general electric circuit voltage detection method (step S57), and the detected line voltage instantaneous value euv to the phase detection unit 47. Supply.

  The phase detection unit 47 detects the line voltage phase θuv between the terminals UV from the instantaneous line voltage euv supplied from the voltage detection unit 46 using a phase detection device (PLL) or the like, and according to Equation (4). The line voltage phase θvw between the terminals VW is calculated (step S58), and θuv is supplied to the UV pulse control unit 48 and θvw is supplied to the VW pulse control unit 49.

  The inter-UV pulse control unit 48 determines whether αQuv supplied from the inter-UV firing angle determination unit 44 matches θuv supplied from the phase detection unit 47 (step S59), and αQuv and θuv match. If it is determined, the UV pulse controller 48 outputs a control signal for firing the thyristor constituting the current control circuit 22 (step S60).

  Further, the inter-VW pulse control unit 49 determines whether αQvw and αRvw supplied from the inter-VW firing angle determination unit 45 coincide with θvw supplied from the phase detection unit 47 (step S61), and αQvw And Vvw control unit 49 outputs a control signal for starting the thyristor constituting the current control circuit 24 (step S62).

  Further, the inter-UV pulse control unit 48 determines whether αRuv supplied from the inter-UV firing angle determination unit 44 matches θuv supplied from the phase detection unit 47 (step S62), and αRuv and θuv are determined. Are determined to match, the UV pulse control unit 48 outputs a control signal for firing the thyristor constituting the current control circuit 26 (step S64).

  When the effective power consumption of the first single-phase load 9 is smaller than the effective power consumption of the second single-phase load 10, the VW firing angle is set so that the second variable resistance circuit 8 is in a non-conduction state. Since the determination unit 45 sets αRvw to 90 degrees, the inter-VW pulse control unit 49 generates a control signal for firing the thyristor constituting the current control circuit 28 of the second variable resistance circuit 8 between the terminals VW. No output is made (step S65).

  FIG. 11 shows a voltage vector (a) and a current vector (b) when the effective power consumption of the first single-phase load 9 is smaller than the effective power consumption of the second single-phase load 10.

  The devices connected to the first single-phase circuit 3 and the second single-phase circuit 4 are both single-phase loads, and the effective power consumption of the first single-phase load 9 is the effective power consumption of the second single-phase load 10. When the amount is smaller than the amount, as shown in FIG. 11B, the current vector IRuv of the first variable resistance circuit 7 connected between the terminals UV is a vector in phase with the voltage vector Euv.

  The U-phase, V-phase, and W-phase current vectors Iu, Iv, and Iw are determined by the following equations (25), (26), and (27), respectively.

<< Equation 9 >>
Iu = Ipm-IC + IRuv (25)
Iv = Ism-Ipm + IC-IL-IRuv (26)
Iw = IL-Ism (27)
The magnitudes of the currents IRuv and IRvw of the first variable resistance circuit 7 and the second variable resistance circuit 8 are determined by the following formulas (28) and (29).

<< Equation 10 >>
IRuv = Ism-Ipm (28)
IRvw = 0 (29)
When the impedances 5, 6, 7, and 8 are controlled as shown in steps S51 to S65, the magnitudes of the current vectors Iu, Iv, and Iw shown in FIG. Respectively coincide with the directions of the phase voltage vectors Eu, Ev, Ew. That is, the power factor of the three-phase power source 2 is 1, and the current of the three-phase power source 2 is a complete balanced three-phase current.

  Accordingly, both the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase loads, and the effective power consumption of the first single-phase load 9 is greater than the effective power consumption of the second single-phase load 10. When the load amount is small, the output current of the three-phase power source 2 can be controlled in a balanced manner even if the load amount changes within the range of power factor 1.

<Control mode: MODE-2, 3, when one is power>
When one of the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 is a single-phase load circuit and one is a single-phase power supply circuit, the control switching unit 35, as shown in FIG. First load active power detection unit 41, first power source active power detection unit 51, second load active power detection unit 42, second power source active power detection unit 52, compensation amount calculation unit 43, and inter-UV firing angle determination unit 44 The inter-VW firing angle determining unit 45, the voltage detecting unit 46, the phase detecting unit 47, the UV pulse control unit 48, and the inter-VW pulse control unit 49 are configured and operated. In addition, the same number is attached | subjected about the same thing as the functional block shown in FIG. 5, and detailed description is abbreviate | omitted.

  The first power source active power detection unit 51 has a function of detecting the active power amount of the first single-phase power source 9 of the first single-phase circuit 3 by a general method for detecting the active power of the electric circuit, and the second power source The active power detection unit 52 has a function of detecting the effective power amount of the second single-phase power supply 10 of the second single-phase circuit 4 by a general method for detecting the active power of an electric circuit.

  In the case of MODE-2 (the first single-phase circuit 3 is a load and the second single-phase circuit 4 is a power supply), the first load active power detection unit 41 and the second power supply active power detection unit 52 operate. In the case of MODE-3 (the first single-phase circuit 3 is a power source and the second single-phase circuit 4 is a load), the first power source active power detector 51 and the second load active power detector 42 operate.

  Next, the operation of the control switching unit 35b will be described based on the flowchart of FIG.

  When the control device 31 starts the control of the conversion circuit 1 in MODE-2, the first load active power detection unit 41 determines the effective power amount of the first single-phase load 9 by a general method for detecting the active power of the electric circuit. It detects (step S71). Further, when the control device 31 starts control of the conversion circuit 1 in MODE-3, the second load active power detection unit 42 uses the common power detection method for the effective power of the second single-phase load 10 by a general electric circuit detection method. The amount is detected (step S71).

  When the control device 31 starts control of the conversion circuit 1 in MODE-2, the first power source active power detection unit 51 uses the active power of the first single-phase power source 9 by a general method for detecting the active power of the electric circuit. The amount is detected (step S72). When the control device 31 starts the control of the conversion circuit 1 in MODE-3, the second power source active power detection unit 52 uses the active power detection method of a general electric circuit to detect the effective power of the second single-phase power source 10. The amount is detected (step S72).

  Respective active power amounts detected by the first load active power detection unit 41 or the second load active power detection unit 42, the first power source active power detection unit 51 or the second power source active power detection unit 52 are stored in the compensation amount calculation unit 43. When supplied, the compensation amount calculation unit 43 first compares the active power consumption amounts of the first single-phase load 9 and the second single-phase load 10.

  When MODE-2, the compensation amount calculation unit 43 follows the following formulas (35), (36), and (37), between the power compensation amount Quv in the variable capacitive impedance circuit 5 between the terminals UV and the terminal VW. The power compensation amount Qvw in the variable inductive impedance circuit 6, the current IRuv of the first variable resistance circuit 7 between the terminals UV, and the current IRvw of the second variable resistance circuit 8 between the terminals VW are calculated (step S73). . Here, the rated line voltage of the three-phase power supply 2 is E, the active power of the first single-phase load 9 is PL1, the primary winding current of the first single-phase transformer 11 is Ipm, and the effective power of the second single-phase power supply 10 Is Ps2, and the primary winding current of the second single-phase transformer 12 is Ism.

<< Equation 11 >>
Ipm-Ism = (PL1-Ps2) / E (35)
Quv = Qvw = E x (Ipm-Ism) x 1/3 ^1/2 (36)
IRuv = IRvw = 0 (37)
The compensation amount calculation unit 43 calculates each power compensation amount according to the above formula, and supplies Quv and IRuv to the UV firing angle determination unit, and supplies Qvw and IRvw to the VW firing angle determination unit.

  Further, when MODE-3, the compensation amount calculation unit 43 follows the following formulas (38), (39), and (40), the power compensation amount Quv in the variable capacitive impedance circuit 5 between the terminals UV, and the terminal VW. A power compensation amount Qvw in the variable inductive impedance circuit 6 between, a current IRuv of the first variable resistance circuit 7 between the terminals UV, and a current IRvw of the second variable resistance circuit 8 between the terminals VW are calculated (step) S73).

<< Equation 12 >>
Ism-Ipm = (PL2-Ps1) / E (38)
Quv = Qvw = E × (Ism-Ipm) × 1/3 ^1/2 (39)
IRuv = IRvw = 0 (40)
The compensation amount calculation unit 43 calculates each power compensation amount according to the above formula, and supplies Quv and IRuv to the UV firing angle determination unit, and supplies Qvw and IRvw to the VW firing angle determination unit.

なお、Q1〜Qn、およびIR1〜IRnの実際の値は、回路構成に従う。 The inter-UV firing angle determining unit 44 and the inter-VW firing angle determining unit 45 preliminarily correspond to the firing angle α with respect to the power compensation amount Q and the resistance current value between the UV and VW as shown in Tables 7 and 8. A data table that records the correspondence of the firing angle α is recorded. The inter-UV firing angle determination unit 44 and the inter-VW firing angle determination unit 45 are supplied with each power compensation amount from the compensation amount calculation unit 43. The firing angles αQuv and αQvw for the supplied Quv and Qvw are set (step S74), the firing angles αRuv and αRvw for IRuv and IRvw are set (step S75), the UV pulse control unit 48, and the VW Each of them is supplied to the inter-pulse controller 49. Here, the inter-UV firing angle determination unit 44 and the inter-VW firing angle determination unit 45 set the firing angles αRuv and αRvw to 90 degrees, respectively.

The actual values of Q1 to Qn and IR1 to IRn depend on the circuit configuration.

  The voltage detection unit 46 detects the line voltage instantaneous value euv between the terminals UV by a general electric circuit voltage detection method (step S76), and the detected line voltage instantaneous value euv to the phase detection unit 47. Supply.

  The phase detection unit 47 detects the line voltage phase θuv between the terminals UV using the phase detection device (PLL) or the like from the line voltage instantaneous value euv supplied from the voltage detection unit 46, and the following equation (41) ), The line voltage phase θvw between the terminals VW is calculated (step S77), θuv is supplied to the UV pulse controller 48, and θvw is supplied to the VW pulse controller 49.

<< Equation 13 >>
θvw = θuv-120 ° (41)
The inter-UV pulse control unit 48 determines whether αQuv supplied from the inter-UV firing angle determination unit 44 matches θuv supplied from the phase detection unit 47 (step S78), and αQuv and θuv match. If it is determined, the UV pulse control unit 48 outputs a control signal for starting the thyristor constituting the current control circuit 22 (step S79).

  Further, the inter-VW pulse control unit 49 determines whether αQvw supplied from the inter-VW firing angle determination unit 45 matches θvw supplied from the phase detection unit 47 (step S80), and αQvw and θvw Are determined to match, the inter-VW pulse control unit 49 outputs a control signal for firing the thyristor constituting the current control circuit 24 (step S81).

  When one of the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 is a single-phase load circuit and one is a single-phase power supply circuit, the first variable resistance circuit 7 and the second variable circuit The inter-UW firing angle determining unit and the inter-VW firing angle determining unit 45 set αRuv and αRvw to 90 degrees so that the resistance circuit 8 is in a non-conducting state. Does not output a control signal for firing the thyristor constituting the current control circuit 26 of the first variable resistance circuit 7 between the terminals UV (step S82). Similarly, the inter-VW pulse control unit 49 does not output a control signal for firing the thyristor constituting the current control circuit 28 of the second variable resistance circuit 8 between the terminals VW (step S83).

  When one of the single-phase devices of the first single-phase circuit 3 and the second single-phase circuit 4 is a single-phase load circuit and one of them is a single-phase power supply circuit, a current vector as shown in FIG. Become.

  The U-phase, V-phase, and W-phase current vectors Iu, Iv, and Iw are determined by the following equations (42), (43), and (44), respectively.

<< Equation 14 >>
Iu = IC-(Ipm-Ism) (42)
Iv = IL-IC (43)
Iw = (Ipm-Ism)-IL (44)
The magnitudes of the currents IRuv and IRvw of the first variable resistance circuit 7 and the second variable resistance circuit 8 are respectively determined by the following formulas (45) and (46).

≪Number 15≫
IRuv = 0 (45)
IRvw = 0 (46)
When the impedances 5, 6, 7, and 8 are controlled as shown in steps S71 to S83, the magnitudes of the current vectors Iu, Iv, and Iw shown in FIG. Respectively coincide with the directions of the phase voltage vectors Eu, Ev, Ew. That is, the power factor of the three-phase power supply 212 is 1, and the current of the three-phase power supply 212 is a complete balanced three-phase current.

  Therefore, when both the first single-phase circuit 3 and the second single-phase circuit 4 are single-phase loads and the active power consumptions of the first single-phase load 9 and the second single-phase load 10 are equal, the load amount Even if the power factor changes within the range of power factor 1, the output current of the three-phase power source 2 can be controlled to be balanced.

  The variable capacitive impedance circuit 5, the variable inductive impedance circuit 6, the first variable resistance circuit 7, and the second variable resistance circuit 8 are a series circuit of the capacitive impedance circuit 21 and the current control circuit 22 shown in FIG. Not only the series circuit of the inductive impedance circuit 23 and the current control circuit 24, the variable resistance circuit and the current control circuits 26 and 28, but also any circuit that can change the impedance at the power source frequency.

  Further, by causing the computer to execute a control program in which each process shown in the flowcharts of FIGS. 4, 6, 8, 10, and 13 performed by the control device 31 in this embodiment is described. The control device 31 may be realized.

It is a figure which shows the structure of an electric circuit. It is a figure which shows the structure of each impedance. It is a figure which shows the structure of a control apparatus. It is a flowchart which shows the rough process sequence of a control apparatus. It is a figure which shows the structure of a control switching part. It is a flowchart which shows the process sequence of a control switching part. It is a figure which shows a voltage vector and an electric current vector. It is a flowchart which shows the process sequence of a control switching part. It is a figure which shows a voltage vector and an electric current vector. It is a flowchart which shows the process sequence of a control switching part. It is a figure which shows a voltage vector and an electric current vector. It is a figure which shows the structure of a control switching part. It is a flowchart which shows the process sequence of a control switching part. It is a figure which shows a voltage vector and an electric current vector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conversion circuit 2 Three-phase power supply 3 1st single phase circuit 4 2nd single phase circuit 5 Variable capacitive impedance circuit 6 Variable inductive impedance circuit 7 1st variable resistance circuit 8 2nd variable resistance circuit 9 1st single phase load, First single-phase power supply 10 Second single-phase load, second single-phase power supply 11 First single-phase transformer 12 Second single-phase transformer 13 Primary winding of first single-phase transformer 14 First single-phase transformer Secondary winding 15 Primary winding of second single-phase transformer 16 Secondary winding of second single-phase transformer 17 First switch 18 Second switch 21 Capacitive impedance circuit 22 Current control circuit 23 Inductive impedance Circuit 24 Current control circuit 25 Resistor 26 Current control circuit 27 Resistor 28 Current control circuit 31 Controller 32 First single-phase circuit state detection unit 33 Second single-phase circuit state detection unit 34 Circuit switching unit 34
35a, b Control switching unit 41 First load active power detection unit 42 Second load active power detection unit 43 Compensation amount calculation unit 44 Inter-UV firing angle determination unit 45 Inter-VW firing angle determination unit 46 Voltage detection unit 47 Phase detection Unit 48 UV pulse control unit 49 VW pulse control unit 51 first power source active power detection unit 52 second power source active power detection unit

Claims (8)

Scott connection system that converts three-phase power into single-phase power by a first single-phase transformer and a second single-phase transformer, and supplies the single-phase power to the first single-phase circuit and the second single-phase circuit, respectively. The conversion circuit of
Connected between terminals U and V, whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and the effectiveness of the first single-phase circuit and the second single-phase circuit A variable capacitive impedance circuit capable of controlling the current between the terminals U and V according to the amount of power consumption;
Connected between terminals V and W, whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and whether the first single-phase circuit and the second single-phase circuit are effective A variable inductive impedance circuit capable of controlling the current between the terminals V and W according to the amount of power consumption;
The first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and are connected in parallel to the variable capacitive impedance circuit, and the first single-phase circuit and the second single-phase circuit A first variable resistance circuit capable of controlling a current between terminals U and V according to the amount of active power consumption of the circuit;
Connected in parallel to the variable inductive impedance circuit, the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits, and the first single-phase circuit and the second single-phase circuit A second variable resistance circuit capable of controlling the current between the terminals V and W according to the amount of active power consumption of the circuit;
One terminal of the primary winding of the first single-phase transformer is switched to the terminal V or the terminal W depending on whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits A first switch that can be connected,
One terminal of the primary winding of the second single-phase transformer is switched to terminal U or terminal V depending on whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits. A second switch that can be connected,
A conversion circuit comprising: The variable capacitive impedance circuit is configured by connecting a variable capacitive impedance and a switching element capable of turning on / off a current in series,
The variable inductive impedance circuit is configured by connecting a variable inductive impedance and a switching element capable of turning on / off a current in series,
2. The conversion circuit according to claim 1, wherein the first variable resistance circuit and the second variable resistance circuit are configured by connecting a resistance and a switching element capable of turning on / off a current in series. Scott connection system that converts three-phase power into single-phase power by a first single-phase transformer and a second single-phase transformer, and supplies the single-phase power to the first single-phase circuit and the second single-phase circuit, respectively. A variable capacitive impedance circuit that is connected between the terminals U and V and can control the current between the terminals U and V, and is connected between the terminals V and W, and the current between the terminals V and W. A controllable variable inductive impedance circuit, connected in parallel to the variable capacitive impedance circuit, connected in parallel to the first variable resistance circuit capable of controlling the current between terminals U and V, and the variable inductive impedance circuit The first variable resistance circuit capable of controlling the current between the terminals V and W, and whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits. Connect one terminal of the primary winding of the single-phase transformer to terminal V Depending on whether the first switch that can be switched to the terminal W and connected, and whether the first single-phase circuit and the second single-phase circuit are a load circuit or a power circuit, the second single-phase transformer A control device that controls a conversion circuit including a second switch that can be connected by switching one terminal of the primary winding to the terminal U or the terminal V;
First single-phase circuit state detecting means for detecting whether the first single-phase circuit is consuming or supplying active power;
Second single-phase circuit state detection means for detecting whether the second single-phase circuit is consuming or supplying active power;
Circuit switching means for outputting a circuit switching signal for switching the connection between the first switch and the second switch according to the detection results of the first single-phase circuit state detection means and the second single-phase circuit state detection means; ,
The variable capacitive impedance circuit, the variable inductive impedance circuit, the first variable resistance circuit, and the second variable resistance according to detection results of the first single phase circuit state detection unit and the second single phase circuit state detection unit Control switching means for outputting a control signal for controlling the circuit;
A control device comprising: The variable capacitive impedance circuit of the conversion circuit is configured by connecting a variable capacitive impedance and a switching element capable of turning on / off a current in series, and the variable inductive impedance circuit includes a variable inductive impedance and a current. Are connected in series, and the first variable resistance circuit and the second variable resistance circuit are connected in series with a resistance and a switching element capable of turning on / off the current. When configured
The control switching means is
When it is detected that the first single-phase circuit is consuming active power, it is assumed that a single-phase load is connected to the first single-phase transformer, and the active power amount of the first single-phase circuit is First load active power detection means for detecting
When it is detected that the second single-phase circuit is consuming active power, it is assumed that a single-phase load is connected to the second single-phase transformer, and the effective power amount of the second single-phase circuit is Second load active power detection means for detecting
From the detected both active power amounts, reactive power amounts compensated by the variable capacitive impedance circuit and the variable inductive impedance circuit, and active power amounts compensated by the first variable resistance circuit and the second variable resistance circuit are obtained. A compensation amount calculating means for calculating;
An inter-UV firing angle determining means for determining an ignition angle of a switching element connected in series to each of the variable capacitive impedance circuit and the first variable resistance circuit from each calculated power compensation amount;
A VW firing angle determining means for determining a firing angle of a switching element connected in series to each of the variable inductive impedance circuit and the second variable resistance circuit from each calculated power compensation amount;
Voltage detection means for detecting respective line voltages between the terminals UV and VW;
Phase detection means for detecting the phase of each detected line voltage;
Switching connected in series to the variable capacitive impedance circuit and the first variable resistance circuit at the firing angle determined by the UV firing angle determining means with respect to the detected line voltage phase between the terminals UV An inter-UV pulse control means for outputting a control signal for igniting the element;
Switching connected in series to the variable inductive impedance circuit and the second variable resistance circuit at a firing angle determined by the VW firing angle determining means with respect to the detected line voltage phase between the terminals VW. VW pulse control means for outputting a control signal for igniting the element;
The control device according to claim 3, further comprising: The control switching means is
When it is detected that the first single-phase circuit supplies active power, it is assumed that a single-phase power source is connected to the first single-phase transformer, and the active power amount of the first single-phase circuit is First power source active power detecting means for detecting
When it is detected that the second single-phase circuit is consuming active power, it is assumed that a single-phase power source is connected to the second single-phase transformer, and the effective power amount of the second single-phase circuit is Second power source active power detecting means for detecting
The control device according to claim 4, further comprising: Scott connection system that converts three-phase power into single-phase power by a first single-phase transformer and a second single-phase transformer, and supplies the single-phase power to the first single-phase circuit and the second single-phase circuit, respectively. A variable capacitive impedance circuit that is connected between the terminals U and V and can control the current between the terminals U and V, and is connected between the terminals V and W, and the current between the terminals V and W. A controllable variable inductive impedance circuit, connected in parallel to the variable capacitive impedance circuit, connected in parallel to the first variable resistance circuit capable of controlling the current between terminals U and V, and the variable inductive impedance circuit The first variable resistance circuit capable of controlling the current between the terminals V and W, and whether the first single-phase circuit and the second single-phase circuit are load circuits or power supply circuits. Connect one terminal of the primary winding of the single-phase transformer to terminal V Depending on whether the first switch that can be switched to the terminal W and connected, and whether the first single-phase circuit and the second single-phase circuit are a load circuit or a power circuit, the second single-phase transformer A control program that operates on a computer that controls a conversion circuit including a second switch that can be connected by switching one terminal of the primary winding to the terminal U or V,
First single-phase circuit state detection means for detecting whether the first single-phase circuit is consuming or supplying active power to the computer;
Second single-phase circuit state detection means for detecting whether the second single-phase circuit is consuming or supplying active power;
Circuit switching means for outputting a circuit switching signal for switching the connection between the first switch and the second switch according to the detection results of the first single-phase circuit state detection means and the second single-phase circuit state detection means; ,
The variable capacitive impedance circuit, the variable inductive impedance circuit, the first variable resistance circuit, and the second variable resistance according to detection results of the first single phase circuit state detection unit and the second single phase circuit state detection unit Control switching means for outputting a control signal for controlling the circuit;
A control program characterized by functioning as a function. The variable capacitive impedance circuit of the conversion circuit is configured by connecting a variable capacitive impedance and a switching element capable of turning on / off a current in series, and the variable inductive impedance circuit includes a variable inductive impedance and a current. Are connected in series, and the first variable resistance circuit and the second variable resistance circuit are connected in series with a resistance and a switching element capable of turning on / off the current. When configured
When the computer detects that the first single-phase circuit is consuming active power, the first single-phase transformer is connected to the first single-phase transformer, and First load active power detection means for detecting the amount of active power;
When it is detected that the second single-phase circuit is consuming active power, it is assumed that a single-phase load is connected to the second single-phase transformer, and the effective power amount of the second single-phase circuit is Second load active power detection means for detecting
From the detected both active power amounts, reactive power amounts compensated by the variable capacitive impedance circuit and the variable inductive impedance circuit, and active power amounts compensated by the first variable resistance circuit and the second variable resistance circuit are obtained. A compensation amount calculating means for calculating;
An inter-UV firing angle determining means for determining an ignition angle of a switching element connected in series to each of the variable capacitive impedance circuit and the first variable resistance circuit from each calculated power compensation amount;
A VW firing angle determining means for determining a firing angle of a switching element connected in series to each of the variable inductive impedance circuit and the second variable resistance circuit from each calculated power compensation amount;
Voltage detection means for detecting respective line voltages between the terminals UV and VW;
Phase detection means for detecting the phase of each detected line voltage;
Switching connected in series to the variable capacitive impedance circuit and the first variable resistance circuit at the firing angle determined by the UV firing angle determining means with respect to the detected line voltage phase between the terminals UV An inter-UV pulse control means for outputting a control signal for igniting the element;
Switching connected in series to the variable inductive impedance circuit and the second variable resistance circuit at a firing angle determined by the VW firing angle determining means with respect to the detected line voltage phase between the terminals VW. VW pulse control means for outputting a control signal for igniting the element;
The control program according to claim 6, wherein the control program is made to function. When it is detected that the first single-phase circuit supplies active power to the computer, a single-phase power source is connected to the first single-phase transformer, and the first single-phase circuit First power source active power detecting means for detecting the amount of active power;
When it is detected that the second single-phase circuit is consuming active power, it is assumed that a single-phase power source is connected to the second single-phase transformer, and the effective power amount of the second single-phase circuit is Second power source active power detecting means for detecting
The control program according to claim 7, wherein the control program is made to function.

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