JP6953689B2 - Adjustment device and adjustment method - Google Patents

Description

The present invention relates to an adjusting device and an adjusting method.

Conventionally, various techniques for stabilizing the electric power supplied from the distribution line have been proposed (see, for example, Patent Documents 1 and 2). Of these, in the technique of Patent Document 2, the primary side of the series transformer is connected in series between the pole transformer and the output terminal on the secondary side (load side) of the pole transformer, and the secondary side of the series transformer is connected. A voltage regulator for adjusting the output voltage of the output terminal is connected to the side. The primary side of the series transformer is connected in parallel with the bypass switch, and when the bypass switch is on, current flows through the bypass switch, and when the bypass switch is off, current flows through the primary side of the series transformer.
Patent Document 1 Japanese Patent Application Laid-Open No. 2003-153443 Patent Document 2 Japanese Patent Application Laid-Open No. 2005-341668

However, if the bypass switch is simply switched from on to off, the current flowing through the bypass switch rushes into the primary side (primary coil) of the series transformer and causes a current change, resulting in an output voltage within the appropriate range (101V ±). It may exceed 6V) or cause system disturbance.

In the first aspect of the present invention, a series transformer in which the primary side is connected in series between the power supply and the power supply output terminal and a power supply output terminal connected to the secondary side of the series transformer via the series transformer. A voltage regulator that adjusts the output voltage of the series transformer, a bypass switch that can switch whether to bypass the primary side of the series transformer, and a secondary current of the series transformer before switching the bypass switch from on to off. , A control device including a control unit that controls according to an output current from a power supply output terminal is provided.

In the second aspect of the present invention, the power output terminal is connected via the series transformer by the voltage adjusting unit connected to the secondary side of the series transformer in which the primary side is connected in series between the power supply and the power output terminal. A voltage adjustment stage that adjusts the output voltage of the series transformer, a switching stage that switches whether to bypass the primary side of the series transformer with a bypass switch, and a secondary current of the series transformer before switching the bypass switch from on to off. Is provided with a control step that controls according to the output current from the power output terminal.

The above outline of the invention does not list all the features of the present invention. A subcombination of these feature groups can also be an invention.

The adjusting device which concerns on this embodiment is shown. The state when the adjusting device is in the stop mode is shown. The state when the adjusting device is in the interconnection preparation mode is shown. The state when the adjusting device is in the current draw control mode is shown. The state when the adjusting device is in the voltage compensation control mode is shown. The operation of the adjusting device is shown.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the inventions that fall within the scope of the claims. Also, not all combinations of features described in the embodiments are essential to the means of solving the invention.

FIG. 1 shows the adjusting device 1 according to the present embodiment together with the power supply 10. The adjusting device 1 adjusts the output voltage between the plurality of power supply output terminals 11 connected to the power supply 10 and outputs the output voltage from the power supply output terminals 11 (a), 11 (b), and 11 (n). The adjusting device 1 includes one or more series transformers 12, a voltage adjusting unit 13, one or more bypass switches 14, and a control unit 15. The adjusting device 1 may further include a current measuring unit 16, a voltage measuring unit 17, and a power supply unit 18.

The power supply 10 may be an AC power supply, and in the present embodiment, as an example, a voltage is converted from a high voltage distribution system of 6600 V, 60 Hz (or 50 Hz) to a low voltage distribution system of about 100 V, 60 Hz (or 50 Hz). A transformer to be supplied (a columnar transformer as an example). The power supply 10 may have three output terminals of u-phase, v-phase and o-phase.

The plurality of power output terminals 11 output power after voltage adjustment by the adjusting device 1. In this embodiment, as an example, the three power output terminals 11 (a), 11 (b), and 11 (n) output single-phase AC power. The voltage between at least one of the power output terminals 11 (a) and 11 (b) as the output terminal of the voltage line and the power output terminal 11 (n) as the output terminal of the neutral wire is adjusted by the adjusting device 1. May be done. The power output terminals 11 (a), 11 (b), and 11 (n) are connected to the u-phase, v-phase, and o of the power supply 10 via the low-voltage lines 110 (a), 110 (b), and 110 (n), respectively. It may be connected to the phase output terminal.

In one or more series transformers 12, the primary side, that is, the primary coil is connected in series to the low piezoelectric line 110 between the power supply 10 and the power output terminal 11, and the secondary side, that is, the secondary coil is connected to the voltage adjusting unit 13. Is connected. The transformer ratio of the series transformer 12 may be configured so that the primary side is higher than the secondary side, and may be, for example, primary side: secondary side = 10: 1 (or 5: 1). In the present embodiment, as an example, two series transformers 12 (a) and 12 (b) are provided on the low voltage lines 110 (a) and 110 (b), but even if only one of them is provided. good.

The voltage adjusting unit 13 adjusts the output voltage of the power supply output terminal 11 via each series transformer 12. For example, the voltage adjusting unit 13 may adjust the output voltage of the power supply output terminal 11 so as to be within the reference range (101 ± 6V as an example).

The voltage adjusting unit 13 may have an inverter 130 and one or more reactors 131.
The inverter 130 adjusts the output voltage between the power supply output terminals 11 by outputting the current flowing through the secondary side of each series transformer 12. For example, the inverter 130 may be a single-phase inverter. The inverter 130 has three output terminals of u-phase, v-phase and o-phase, of which the u-phase and o-phase output terminals are connected to the series transformer 12 (a) and output of the v-phase and o-phase. The terminals may be connected to the series transformer 12 (b). The inverter 130 may be supplied with DC power from the power supply unit 18 described later. The switching frequency of the inverter 130 may be 20 kHz as an example.

One or more reactors 131 smooth the current output by the inverter 130. In the present embodiment, as an example, two reactors 131 (u) and 131 (v) are provided between the u-phase and v-phase output terminals of the inverter 130 and the series transformers 12 (a) and 12 (b). Has been done. Instead of / in addition to the reactor 131, another smoothing circuit may be provided at the output terminal of the inverter 130.

One or a plurality of bypass switches 14 are connected so as to be able to switch whether or not to bypass the primary side of the series transformer 12. For example, each bypass switch 14 is connected in parallel with the primary coil of the corresponding series transformer 12 to the low voltage line 110 between the power supply 10 and the power supply output terminal 11, so that the primary coil can be short-circuited. There is. In this embodiment, as an example, two bypass switches 14 (a) and 14 (b) are connected in parallel with the primary coils of the two series transformers 12 (a) and 12 (b).

The control unit 15 controls each unit in the adjusting device 1. The control unit 15 may include a mode management unit 151, an inverter control unit 152, a power supply control unit 153, an adjustment voltage calculation unit 154, and a bypass switch control unit 155. However, the control unit 15 may have only the bypass switch control unit 155.

The mode management unit 151 controls the operation mode of the adjusting device 1. For example, the mode management unit 151 may set the adjusting device 1 to any one of a stop mode, an interconnection preparation mode, a current draw control mode, and a voltage compensation control mode.

Here, the stop mode is a mode in which the output voltage between the power output terminals 11 is not adjusted. In the stop mode, the bypass switch 14 is kept on and the series transformer 12 is not connected.

The interconnection preparation mode is a mode for preparing for the transition from the stop mode to the current draw control mode. In the interconnection preparation mode, the secondary current of the series transformer 12 is controlled according to the output current from the power supply output terminal 11 before the bypass switch 14 is switched from on to off to interconnect the series transformer 12.

The current draw control mode is a mode for preparing for transition from the interconnection preparation mode to the voltage compensation control mode. In the current draw control mode, the bypass switch 14 is kept off and the series transformer 12 is connected so that the current corresponding to the load current from the power output terminal 11 flows to the primary side of the series transformer 12. In addition, a current is passed through the series transformer 12.

The voltage compensation control mode is a mode in which the bypass switch 14 is kept off and the connected series transformer 12 adjusts the output voltage outside the reference range within the reference range.
Details of the operation of the adjusting device 1 in these operation modes will be described later.

The inverter control unit 152 controls the inverter 130. For example, the inverter control unit 152 includes a system voltage compensation control unit 1521 that operates the voltage adjustment unit 13 in the voltage compensation control mode, and a load current lead-in control unit 1522 that operates the voltage adjustment unit 13 in the current draw control mode. The operation of these parts will be described in detail later.

The power supply control unit 153 calculates the DC voltage to be supplied to the inverter 130. The supply power control unit 153 may supply the calculated voltage value to the power supply unit 18 (as an example, the converter 181 described later).

The adjustment voltage calculation unit 154 determines the voltage deviation to be adjusted by the adjustment device 1, that is, the target voltage (voltage within the range of 101 ± 6V as an example) and the effective value of the voltage measured by the voltage measurement unit 17 described later. Calculate the deviation of. The adjusted voltage calculation unit 154 may supply the calculated voltage deviation to the system voltage compensation control unit 1521 and the power supply control unit 153 of the inverter control unit 152.

The bypass switch control unit 155 controls on / off switching of each bypass switch 14.

The current measuring unit 16 measures the output current from the power supply output terminal 11. For example, the current measuring unit 16 may measure the current flowing through the low piezoelectric line 110 by using the current sensor 160 provided on each low piezoelectric line 110 between the series transformer 12 and the power output terminal 11. .. Further, the current measuring unit 16 may further measure the current flowing to the secondary side by using the current sensor 160 provided on the secondary side of each series transformer 12. The current measuring unit 16 may supply the measurement result to the load current lead-in control unit 1522 in the control unit 15.

The voltage measuring unit 17 measures the output voltage between the power supply output terminals 11. For example, the voltage measuring unit 17 may measure the voltage between the low piezoelectric lines 110 (a) and 110 (n) and the voltage between the low piezoelectric lines 110 (b) and 110 (n). The voltage measuring unit 17 may supply the measurement result to the adjusted voltage calculation unit 154 in the control unit 15.

The power supply unit 18 supplies power to the voltage adjustment unit 13. In the present embodiment, as an example, the power supply unit 18 receives the electric power from the power source 10 and supplies the electric power to the voltage adjusting unit 13. The power supply unit 18 may include a converter 181, a smoothing capacitor 182, and a reactor 183.

The converter 181 converts AC power into DC power. In the converter 181 the input side (AC side) terminal is connected to the low piezoelectric lines 110 (a) and 110 (b) on the upstream side of the series transformer 12, and the output side (DC side) terminal is the voltage adjusting unit 13 ( As an example, it may be connected to an inverter 130). For example, the converter 181 may supply DC power of about 400 to 500 V to the voltage adjusting unit 13.

The smoothing capacitor 182 may be connected between the output terminals of the converter 181.
The reactor 183 is provided between the low voltage line 110 (a) and the converter 181 to smooth the current and boost the voltage between the input side terminals of the converter 181. From the viewpoint of smoothing the current, the leakage inductance of the power supply 10 which is a transformer may be used instead of / in addition to the reactor 183.

The electric power supply unit 18 may supply the electric power supplied from another power source (for example, a private power generation facility) different from the power source 10 to the voltage adjusting unit 13. Further, the power supply unit 18 may supply AC power to the voltage adjustment unit 13. In this case, the converter 181 and the smoothing capacitor 182 may be provided in the voltage adjusting unit 13.

According to the above adjusting device 1, the current flowing to the secondary side of the series transformer 12 is controlled according to the output current from the power supply output terminal 11 before the bypass switch 14 is switched from on to off. The impedance of the primary coil of the device 12 can be reduced to increase the current in the primary coil, and the output current can be adjusted to the output current originally flowing through the bypass switch 14. Therefore, since the bypass switch 14 can be switched off with at least a part of the current flowing through the bypass switch 14 flowing to the primary side of the series transformer 12 in advance, the current flowing through the bypass switch 14 is the series transformer 12. It is possible to reduce a large current change due to plunging into the primary side (primary coil). Therefore, it is possible to prevent the output voltage from exceeding the appropriate range (101V ± 6V) or causing system disturbance.

Subsequently, each operation mode of the adjusting device 1 will be described.

FIG. 2 shows a state when the adjusting device 1 is in the stop mode. In this mode, the control unit 15 does not adjust the output voltage between the power output terminals 11.

In the stop mode, the bypass switch control unit 155 turns on each bypass switch 14. As a result, the current from the power supply 10 flows through each bypass switch 14. Specifically, when the bypass switch 14 is on, the impedance of the bypass switch 14 is very small compared to the impedance of the coil on the primary side of the series transformer 12, so that most of the current from the power supply 10 is bypassed. Flow through switch 14. Then, the voltage between the low piezoelectric lines 110 (a) and 110 (n) and between the low piezoelectric lines 110 (a) and 110 (n) becomes the voltage between the power supply output terminals 11 as it is.

Further, the inverter control unit 152 and the supply power control unit 153 disable the inverter 130 and the converter 181. For example, the inverter control unit 152 and the supply power control unit 153 may turn off the pulse signal of the control command applied to the inverter 130 and the converter 181. As a result, the loss generated in these conversion units is reduced, and power can be supplied to the low-voltage distribution system with high efficiency. Further, the life of the adjusting device 1 is extended. The converter 181 does not have to be disabled.

FIG. 3 shows a state when the adjusting device 1 is in the interconnection preparation mode. In this mode, the control unit 15 prepares to shift from the stop mode to the current draw control mode.

For example, the bypass switch control unit 155 continuously turns on each bypass switch 14 from the stop mode. As a result, the current from the power supply 10 flows through the bypass switch 14, and the voltage between the low piezoelectric lines 110 (a) and 110 (n) and between the low piezoelectric lines 110 (a) and 110 (n) remains unchanged. It becomes the voltage between the power output terminals 11.

Next, the power supply control unit 153 supplies power from the power supply unit 18 to the voltage adjustment unit 13. For example, the converter 181 of the power supply unit 18 may convert the input AC power into DC power and supply it to the inverter 130.

Further, the control unit 15 controls the secondary current of each series transformer 12 according to the output current from the power supply output terminal 11. For example, the load current pull-in control unit 1522 may control the voltage adjusting unit 13 to output a secondary current according to the measurement result by the current measuring unit 16 to each series transformer 12. As an example, the inverter 130 of the voltage adjusting unit 13 receives the drive power from the converter 181 and the current value of the output current from the inverter 130 is predetermined with respect to the current value of the load current from the power supply output terminal 11. Current may be gradually passed through each series transformer 12 so as to correspond within the tolerance. Specifically, if the transformation ratio of the series transformer 12 is primary: secondary = 1: m, the load current lead-in control unit 1522 and the supply power control unit 153 have the output current value of the inverter 130 as the load current value /. A control command may be given to the inverter 130 and the converter 181 so as to be m. The current value of the output current from the inverter 130 and the current value of the load current from the power supply output terminal 11 are measured by the current measuring unit 16, respectively.

As a result, before turning off the bypass switch 14 to connect the series transformer 12 in the current draw control mode, the current corresponding to the output current from the power supply output terminal 11 is supplied to the primary side of the series transformer 12 in advance. Is swept away. As a result, most of the current to the power output terminal 11 flows on the primary side of the series transformer 12, and the current flowing through the bypass switch 14 can be reduced or made substantially zero.

FIG. 4 shows a state when the adjusting device 1 is in the current draw control mode. In this mode, the control unit 15 puts the adjusting device 1 in a state where it can shift to the voltage compensation control mode.

For example, the bypass switch control unit 155 turns off each bypass switch 14 at the time of transition from the interconnection preparation mode. As a result, all the current from the power supply 10 flows through the primary side of each series transformer 12.

Next, the power supply control unit 153 supplies power from the power supply unit 18 to the voltage adjustment unit 13. As an example, the converter 181 of the power supply unit 18 may convert the input AC power into DC power and supply it to the inverter 130.

Further, in the load current pull-in control unit 1522 of the control unit 15, the current value of the output current from the inverter 130 is allowed with respect to the current value of the load current from the power supply output terminal 11 according to the measurement result by the current measurement unit 16. Control is performed so as to correspond within the range of the error. As an example, the inverter 130 of the voltage adjusting unit 13 receives the drive power from the converter 181 and the output current from the inverter 130 with respect to the current value of the load current from the power supply output terminal 11 as in the interconnection preparation mode. A current may be passed through each series inverter 12 so that the current values of the above correspond to each other within the tolerance.

FIG. 5 shows a state when the adjusting device 1 is in the voltage compensation control mode. In this mode, the control unit 15 adjusts the output voltage outside the reference range within the reference range.

For example, the bypass switch control unit 155 continuously turns off each bypass switch 14 from the current draw control mode. As a result, the current from the power supply 10 flows through the primary side of each series transformer 12.

Further, the control unit 15 controls the secondary current output from the voltage adjusting unit 13 to each series transformer 12 according to the output voltage. For example, the control unit 15 controls the secondary current output to the series transformer 12 so that the output voltage outside the reference range is within the reference range.

As an example, the adjustment voltage calculation unit 154 converts the voltage measured by the voltage measurement unit 17 into a voltage effective value and a voltage phase, supplies the voltage effective value to the mode management unit 151, and supplies the voltage phase to the system voltage compensation control unit. Supply to 1521. Further, the adjustment voltage calculation unit 154 calculates the voltage deviation to be adjusted from the target voltage held inside and the effective value of the measured voltage, and outputs the calculation results to the system voltage compensation control unit 1521 and the supply power control unit. Supply to 153.

The system voltage compensation control unit 1521 and the power supply control unit 153 include a voltage adjustment unit 13 (inverter 130 as an example) and a power supply unit 18 (as an example) so that the primary side voltage of the series transformer 12 becomes a voltage corresponding to a voltage deviation. It controls the converter 181). For example, if the transformation ratio of the series transformer 12 is primary: secondary = 1: m, the system voltage compensation control unit 1521 and the supply power control unit 153 set the output voltage of the inverter 130 to be a voltage deviation × m. A control command is given to the inverter 130 and the converter 181.

The system voltage compensation control unit 1521 sets the voltage applied to the low-voltage line 110 (a) by the series transformer 12 to be in phase with the voltage phase between the low-voltage lines 110 (a) and 110 (n). good. The system voltage compensation control unit 1521 may have a phase in which the voltage applied to the low piezoelectric line 110 (b) by the series transformer 12 is inverted by 180 °.

As a result, a voltage with a voltage deviation is generated on the primary side of the series transformer 12. As a result, the voltage deviation with respect to the voltage supplied from the power supply 10 between the low piezoelectric lines 110 (a) and 110 (n) and / or between the low piezoelectric lines 110 (a) and 110 (n). A voltage is applied, and the voltage between the power output terminals 11 becomes the target voltage.

FIG. 6 shows the operation of the adjusting device 1. When the adjusting device 1 starts operation, the mode management unit 151 sets the adjusting device 1 to the stop mode (S11). For example, the mode management unit 151 turns on each bypass switch 14 by the bypass switch control unit 155. Further, the mode management unit 151 disables the inverter 130 and the converter 181 by the inverter control unit 152 and the supply power control unit 153.

Next, the mode management unit 151 determines whether or not the output voltage between the power supply output terminals 11 is out of the reference range based on the measurement result by the voltage measuring unit 17 (S13). For example, the effective value of the voltage between the low piezoelectric lines 110 (a) and 110 (n) measured by the voltage measuring unit 17 and the effective value of the voltage between the low piezoelectric lines 110 (b) and 110 (n). The adjustment voltage calculation unit 154 may supply the value and the value to the mode management unit 151. The mode management unit 151 may monitor whether or not the supplied voltage effective value is out of the reference range.

When it is determined in S13 that the output voltage is within the reference range (S13; No), the control unit 15 proceeds to S13 and maintains the stop mode.

When it is determined in S13 that the output voltage is out of the reference range (S13; Yes), the mode management unit 151 shifts the adjusting device 1 to the interconnection preparation mode (S15). For example, the mode management unit 151 continues to keep each bypass switch 14 on by the bypass switch control unit 155. Further, the control unit 15 controls the secondary current of each series transformer 12 according to the output current from the power supply output terminal 11. As a result, the secondary current of the series transformer 12 is controlled according to the output current from the power supply output terminal 11 before the bypass switch 14 is switched from on to off in S17 described later. Therefore, when the bypass switch 14 is switched, the current change due to the current flowing through the bypass switch 14 rushing into the primary side (primary coil) of the series transformer is reduced. The above processing of S15 is an example of the control stage.

Next, the mode management unit 151 shifts the adjusting device 1 to the current draw control mode (S17). For example, the mode management unit 151 switches each bypass switch 14 from on to off by the bypass switch control unit 155. Further, the control unit 15 continues to control the secondary current of each series transformer 12 according to the output current from the power supply output terminal 11.

The timing for switching the bypass switch 14 from on to off may be less than 100 ms, preferably less than 20 ms (cycle in the case of 50 Hz) after the processing of S15 is performed. Further, this timing may be a timing at which the magnitude of the output current, which is an alternating current, becomes equal to or less than a reference value (for example, 0A). As a result, even when the current flowing through the bypass switch 14 slightly rushes to the primary side of the series transformer, the change in current due to the rush can be reduced. The above processing of S17 is an example of the switching stage.

Next, the mode management unit 151 shifts the adjusting device 1 to the voltage compensation control mode (S19). For example, the mode management unit 151 continues to keep each bypass switch 14 off by the bypass switch control unit 155. Further, the control unit 15 adjusts the voltage on the primary side of the series transformer 12 by controlling the secondary current output from the voltage adjusting unit 13 to each series transformer 12 according to the output voltage. The above processing of S19 is an example of the voltage adjustment stage.

Next, the mode management unit 151 determines whether or not the output voltage between the power supply output terminals 11 is within the reference range (S21). The mode management unit 151 may determine whether the output voltage is within the second reference range (101 ± 2V as an example) narrower than the reference range (101 ± 6V as an example). The mode management unit 151 may determine whether or not the output voltage between the power supply output terminals 11 has reached the target voltage.

When it is determined in S21 that the output voltage is out of the reference range (S21; No), the control unit 15 proceeds to S19 to maintain the voltage compensation control mode. When it is determined in S21 that the output voltage is within the reference range (S21; Yes), the control unit 15 shifts the process to S11. As a result, the adjusting device 1 shifts to the stop mode and the bypass switch 14 is switched on when the output voltage is within the reference range.

In the above operation, the adjusting device 1 may end the operation when it receives a command to end the operation.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that such modified or improved forms may also be included in the technical scope of the present invention.

The order of execution of operations, procedures, steps, steps, etc. in the devices, systems, programs, and methods shown in the claims, specification, and drawings is particularly "before" and "prior to". It should be noted that it can be realized in any order unless the output of the previous process is used in the subsequent process. Even if the scope of claims, the specification, and the operation flow in the drawings are explained using "first", "next", etc. for convenience, it means that it is essential to carry out in this order. It's not a thing.

1 Regulator, 10 power supply, 11 power supply output terminal, 12 series inverter, 13 voltage regulator, 14 bypass switch, 15 control unit, 16 current measurement unit, 17 voltage measurement unit, 18 power supply unit, 110 low voltage line, 130 Inverter, 131 Reactor, 151 Mode Management Unit, 152 Inverter Control Unit, 153 Supply Power Control Unit, 154 Adjusted Voltage Calculation Unit, 155 Bypass Switch Control Unit, 160 Current Sensor, 181 Converter, 182 Smoothing Condenser, 183 Reactor, 1521 Systems Voltage compensation control unit, 1522 Load current lead-in control unit

Claims (8)

A series transformer with the primary side connected in series between the power supply and the power supply output terminal,
A voltage adjusting unit connected to the secondary side of the series transformer and adjusting the output voltage of the power supply output terminal via the series transformer.
A bypass switch that can switch whether to bypass the primary side of the series transformer and
When the output voltage is out of the reference range while the bypass switch is on, the secondary current of the series transformer is controlled according to the output current from the power supply output terminal, and then the bypass is used. and toggle its control unit to turn off the switch,
With
The power source is an AC power source.
The control unit
An adjusting device that switches the bypass switch from on to off at a timing when the magnitude of the instantaneous value of the output current becomes equal to or less than a reference value. Further provided with a current measuring unit for measuring the output current,
Under the control of the control unit, the voltage adjusting unit outputs the secondary current according to the measurement result of the current measuring unit to the series transformer before switching the bypass switch from on to off. The adjusting device according to claim 1. Further provided with a power supply unit that receives power from the power source and supplies power to the voltage adjustment unit.
According to claim 1 or 2 , the control unit starts supplying power from the power supply unit to the voltage adjustment unit in response to the output voltage being out of the reference range while the bypass switch is on. The adjusting device described. Any one of claims 1 to 3 in which the control unit controls the secondary current output from the voltage adjusting unit to the series transformer after the bypass switch is turned off according to the output voltage. The adjusting device described in the section. The adjusting device according to claim 4 , wherein the control unit switches the bypass switch on when the output voltage is within the reference range while the bypass switch is off. The voltage adjusting unit
An inverter that outputs the current flowing to the secondary side of the series transformer,
A reactor that smoothes the current output by the inverter,
The adjusting device according to any one of claims 1 to 5. The adjusting device according to any one of claims 1 to 6 , wherein the power supply is a transformer that converts a voltage from a high-voltage distribution system to a low-voltage distribution system. Voltage adjustment that adjusts the output voltage of the power supply output terminal via the series transformer by the voltage adjustment unit connected to the secondary side of the series transformer in which the primary side is connected in series between the power supply and the power supply output terminal. Stages and
A switching stage in which whether or not to bypass the primary side of the series transformer is switched by a bypass switch, and
When the output voltage is out of the reference range while the bypass switch is on, the secondary current of the series transformer is controlled according to the output current from the power supply output terminal, and then the bypass is used. a switching Ru control stage turning off the switch,
With
The power source is an AC power source.
In the control stage, an adjustment method for switching the bypass switch from on to off at a timing when the magnitude of the instantaneous value of the output current becomes equal to or less than a reference value.

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