JP2002017088A - Controller for power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish pulse-width modulation control by spatial vector at low switching frequency with accuracy. SOLUTION: The controller for power conversion devices is provided with a power conversion main circuit that synthesizes the DC outputs of n converters (2a to 2d) fed as input with AC voltages different in phase from one another and supplies a common DC load (6) with DC power. All the current vectors of AC current the power conversion devices can produce are divided in advance into a plurality of divisions in terms of phase, amplitude, and the like. To which division an AC current command vector to zero DC current deviation belongs is detected, and an output current vector corresponding to the AC current command vector is selected from among the current vectors belonging to the detected division. The converters are PWM-controlled by the output current vector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a power converter using a switching element, and more particularly to a DC control with a low switching frequency and a high accuracy when performing PWM (pulse width modulation) control using a space vector. The present invention relates to a control device for a power conversion device capable of reducing DC current ripple and AC current harmonics.

[0002]

2. Description of the Related Art FIG. 14 is a circuit diagram and a block diagram showing a configuration example of a control device of a conventional power converter.

[0003] The power converter shown in FIG.
And a converter group 3 which converts the output AC power of the phase shift transformer group 2 into DC power and supplies the DC power to a DC load 6. The phase-shifting transformer group 2 includes four unit phase-shifting transformers 2a to 2d having the same voltage magnitude and an output voltage phase difference of 15 ° from each other. The converter group 3 is composed of four unit converters 3a to 3d corresponding to the unit phase shift transformers 2a to 2d. In the following description, the unit phase shift transformer and the unit converter will be simply referred to as phase shift transformers or converters, respectively. Assuming that the output voltage phase of each phase-shifting transformer is 0 ° with reference to the output voltage phase of the phase-shifting transformer 2a, the phase-shifting transformer 2b is 15 ° and the phase-shifting transformer 2c is 30 °.
° and the phase shift transformer 2d is 45 °. Adjustment of these output voltage phases can be performed by dividing each phase winding, setting its voltage, and dividing windings extending over each phase, including the well-known delta connection and star connection, as shown schematically. It can be easily obtained by connection or the like. Four phase-shift transformers 2a to 2d
Are connected in parallel to a common AC power supply 1 by connecting the primary terminals in common, and the secondary terminals are connected to the AC mizus of the converters 3a to 3d in a one-to-one relationship. This constitutes a well-known 24-phase connection type circuit.

FIG. 15 shows a converter 3 and a DC load 6 of the main circuit.
3 shows an example of a circuit in which a DC filter 5 is interposed between the two. The DC filter 5 is provided to reduce the ripple of the output voltage of the converter 3, and includes a reactor 5 a connected in series to the current circuit and a capacitor connected in parallel to the DC load 6 on the load side thereof. 5b
This is the next low-pass filter. In order to suppress the resonance between the reactor 5a and the capacitor 5b, a resonance suppression resistor 5c is connected in series with the capacitor 5b.

The unit converters 3a to 3d shown in FIGS. 14 and 15
As shown in FIG. 16, each of the six-arm self-extinguishing type semiconductor switching elements 4 connected in a three-phase bridge
u to 4z. As these semiconductor switching elements, for example, IEGT (Injection Enhanc
ed Gate Transistor). Since the switching elements 4u to 4z have parasitic diodes connected in antiparallel inside the elements, a series diode for preventing reverse conduction is illustrated. In the figure, a protection diode is connected in series to each switching element.

Referring again to FIG. 14 and FIG. A DC current value flowing through the DC load 6 is detected by the current detector 7, and the AC voltage of the AC power supply 1, that is, the input voltage of the phase shift transformer group 2 is guided to the synchronization detection circuit 9 via the voltage detector 8.
Therefore, a synchronization signal is generated at a specific phase point serving as a reference for the AC voltage.

Hereinafter, the operation of the main circuit shown in FIGS. 14 and 15 will be described with reference to FIGS. 16 to 19 together with the configuration of the control device.

The output current of the power converter, that is, the DC load
6 is generated by the DC current command generation circuit 10.
DC command value Id^*Is determined by DC power
DC current command value generated by the flow command generation circuit 10
Id^*And the DC current value detected by the current detector 7
By taking the difference from Id, the DC current deviation ΔI is obtained.
This is input to the current controller (ACR) 11. Current control
The device 11 is for setting the DC current deviation ΔI to zero (zero).
That is, the DC current value Id is changed to the DC current command value Id. ^*Matches
A control amount is generated for the control. On the other hand, the synchronization detection circuit 9
Generates and outputs a synchronization signal from the AC voltage of the AC power supply 1.
It is sent to the current command vector generation circuit 12. Output current finger
The instruction vector generation circuit 12 is generated by the current controller 11.
The generated control amount is defined as an amplitude element M,
The output current is defined as the synchronization signal generated as
Generate a command vector.

The space vector control is performed using the output current command vector. Here, the principle of the space vector control in the case of the transformer multiplexing method will be described.

[0010] As shown in FIG.
The switching elements 4u to 4z of the arms U to Z are provided. Depending on the conduction state of the switching elements of each arm, as shown in FIGS. 17 and 18, the arms are short-circuited and the zero current vector ◎ (U -X arm conduction,
VY arm conduction, WZ arm conduction) and “six types” of unit current vectors (UZ arm conduction),
(VZ arm conduction), (VX arm conduction),
(WX arm conduction), (WY arm conduction),
(U-Y arm conduction) can be output. In FIG.
Each phase AC current Iu, Iv,
It shows how Iw flows.

As shown in FIG. 14, the phase shift transformers 2a to 2a
d, four converters 3a to 3
The unit current vector of 3d has a phase difference of 15 ° according to the phase difference of the phase shift transformers 2a to 2d connected to the converters 3a to 3d. Therefore, as shown in FIGS. 18 and 19, in the case of a 24-phase configuration, four converters 3a to 3d
There are seven combined current vectors (output current vectors) for the combination of the unit current vector and the zero vector of each converter.
⁴ ) The large number of output current vector choices
This indicates that the vector density is high, which leads to improvement in control accuracy when a current command vector is given.

In FIG. 14, according to the output current command vector generated by the output current command vector generation circuit 12, an output current vector selection circuit 13 outputs the above-mentioned 2401 output currents obtained by the output current vector generation circuit 14. An output current vector that is the same as or approximate to the output current command vector is selected from vectors (composite vector of unit current vectors). As an example of the selection method, an output current command vector (Xo, Yo) and 2401 output current vectors (Xn, Yn: n = 1 to 240)
1), the least squares method of selecting the output current vector (Xn ′, Yn ′) that minimizes the deviation E can be mentioned. That is, (Xo−Xn) ² + (Yo−Yn) ² = Emin → (Xn ′, Yn ′) (1)

The output current vector selected by the output current vector selection circuit 13 is a unit current vector distribution circuit 15
As a result, the converter 4 that has become a component of the output current vector
The current is divided into the unit current vectors for the respective units, and the switching elements 4u to 4z of each arm of the four converters 3a to 3d are subjected to pulse width modulation control via the gate signal generation circuit 16.

In the space vector control, since the output current can be controlled by the combination of the unit current vectors A, B, C, and D (combined current vector S) that can be generated by the unit converter, on / off control of the switching element is not required. The switching frequency can be reduced without performing it as necessary.

[0015]

However, FIG.
Alternatively, in the conventional control device shown in FIG. 15, in the case of a 24-phase configuration, the output current vector selection circuit 13 is used for each control cycle from among "2401" output current vectors generated by the output current vector generation circuit 14. In order to select an output current vector that is the same as or similar to the output current command vector generated by the output current command vector generation circuit 12, a large selection time (control operation time) is required. The delay due to the control calculation time contributes to a decrease in the following ability, which is one aspect of high-precision control.

In selecting a zero vector, there are three types of selectable pair phases (the UX phase, the VY phase, and the WZ phase). Switching may occur, leading to an increase in the switching frequency.

When a DC filter 5 is provided on the output side of the power converter as shown in FIG. 15, high-precision control can be performed by the control device, while the output current command vector generation circuit 12 If the output current command vector includes disturbances such as harmonic components and control delays, it becomes a factor of deteriorating stability and followability, which are one aspect of high-precision control.

Accordingly, an object of the present invention is to provide a control device of a power conversion device capable of realizing pulse width modulation control using a space vector at a low switching frequency with high accuracy.

Still another object of the present invention is to provide a control device for a power conversion device that has good stability and good tracking performance even when a DC filter is provided on the output side of the power conversion device. .

[0020]

In order to achieve the above object, a control device for a power converter according to claim 1 has the same output voltage magnitude and each of 60 ° / n (n ≧ 2). N phase-shifting transformers having a phase difference and switching elements are bridge-connected to convert AC power to DC power.
The primary terminals of the n phase-shift transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of the n converters. 1 each
In a control device of a power conversion device having a power conversion main circuit connected in a one-to-one relationship and combining the DC outputs of n converters and supplying DC power to a common DC load, the DC power is supplied to the DC load Current control means for generating a control amount of a DC current from a difference between a command value of a DC current and a detection value of a DC current flowing to a DC load; a synchronization detection means for obtaining a synchronization signal synchronized with the AC voltage of an AC power supply; Output current command vector generating means for generating an output current command vector of the power conversion device from a control amount of the DC current and a synchronization signal obtained from the AC voltage; and an output for providing all the current vectors of the AC current that the power conversion device can generate. It is assumed that the current vector generating means and the current vector diagram are divided into 60 ° / n phase ranges within a phase angle of 0 to 360 °, and the 6n phase division ranges are assigned phase range numbers of 1 to 6n. A phase range number detecting means for detecting a phase range number in which the output current command vector generated by the output current command vector generating means exists; and a phase range number among the output current vectors generated by the output current vector generating means. An output current vector detector within the phase division range for detecting a current vector within the phase division range corresponding to the phase range number detected by the number detection means, and an output corresponding to the output current command vector from the detected phase division range Output current vector selecting means for selecting a current vector, and unit current vector distributing means for distributing the output current vector selected by the output current vector selecting means to n unit current vectors according to the n converters. Means for controlling the pulse width modulation of the converter in accordance with the unit current vector. .

According to the first aspect of the present invention, when selecting a current vector corresponding to the current command vector, the current vector is selected from within a division range (every 60 ° / n) corresponding to the phase angle of the current command vector. By doing so, it is possible to shorten the control calculation time to about 1 / (6 · n), improve the followability, and realize high-precision control.

According to a second aspect of the present invention, the control device for the power converter has the same magnitude of the output voltage and each of 60 ° / n (n ≧
2) n phase-shift transformers having a phase difference, and n converters configured by bridge-connecting switching elements to convert AC power into DC power, and include n phase-shift transformers. The primary terminals are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of n converters in a one-to-one relationship, respectively. In a control device of a power conversion device including a power conversion main circuit that combines DC output and supplies DC power to a common DC load,
A current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detection value of the DC current flowing to the DC load; and obtaining a synchronization signal synchronized with the AC voltage from the AC power supply. Synchronization detection means, output current command vector generation means for generating an output current command vector of the power conversion device from a control amount of DC current and a synchronization signal obtained from the AC voltage, and all of the AC currents that the power conversion device can generate. Output current vector generating means for providing a current vector, and the current vector diagram are divided into amplitude ranges of 100% / n among current vector amplitudes of 0 to 100%, and n amplitude division range numbers are assigned. An amplitude range number detecting means for detecting an amplitude range number in which the output current command vector generated by the output current command vector generating means exists; Output current vector detection means for detecting a current vector within an amplitude division range corresponding to the amplitude range number detected by the amplitude range number detection means from the output current vectors generated by the stages; Output current vector selection means for selecting an output current vector according to the output current command vector from the amplitude division range, and the output current vector selected by the output current vector selection means for n converters according to n converters. And a unit for distributing the unit current vector to the unit current vectors, and a unit for performing pulse width modulation control of the converter in accordance with the unit current vector.

According to the second aspect of the present invention, when selecting a current vector corresponding to the current command vector, the current vector is selected from within a division range (every 100% / n) corresponding to the amplitude of the current command vector. By doing so, the vector selection time, that is, the control calculation time can be reduced to about 1 / n, and the follow-up property can be improved to realize high-precision control.

According to a third aspect of the present invention, the control device of the power conversion device has the same magnitude of the output voltage, and each of the output voltages is 60 ° / n (n ≧ n).
2) n phase-shift transformers having a phase difference, and n converters configured by bridge-connecting switching elements to convert AC power into DC power, and include n phase-shift transformers. The primary terminals are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of n converters in a one-to-one relationship, respectively. In a control device of a power conversion device including a power conversion main circuit that combines DC output and supplies DC power to a common DC load,
A current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detection value of the DC current flowing to the DC load; and obtaining a synchronization signal synchronized with the AC voltage from the AC power supply. Synchronization detection means, output current command vector generation means for generating an output current command vector of the power conversion device from a control amount of DC current and a synchronization signal obtained from the AC voltage, and all of the AC currents that the power conversion device can generate. Output current vector generating means for providing a current vector, and phase angle detecting means for detecting a phase angle of the output current command vector generated by the output current command vector generating means,
A phase angle range detecting means for setting a phase angle range by providing a hysteresis width to the detected phase angle, and detecting a current vector included in the phase angle range from output current vectors generated by the output current vector generating means; Amplitude detection means for detecting the amplitude of the output current command vector generated by the output current command vector generation means, and an output current generated by the output current vector generation means by setting a hysteresis width to the detected amplitude to set an amplitude range; An amplitude range detecting means for detecting a current vector included in the amplitude range from the vectors, and a phase angle range of the current vector detected by the phase angle range detecting means and an amplitude range of the current vector detected by the amplitude range detecting means. Output current vector selecting means for selecting one current vector from the overlapping area; A unit current vector distribution unit that distributes the output current vector selected by the flow vector selection unit to n unit current vectors according to the n converters, and a pulse width modulation unit that converts the converter according to the unit current vector Control means.

According to the third aspect of the present invention, when selecting a current vector corresponding to the current command vector, the hysteresis width of the phase angle where the current command vector exists is set to Δθ / 36.
0 °, when the hysteresis width of the amplitude of the current vector in which the current command vector exists is ΔM / 100%, by selecting the current command vector from the range surrounded by the hysteresis width of the phase angle and the amplitude, Set the control operation time to (△
θ / 360 °) × (ΔM / 100%), and the follow-up performance can be improved to realize high-precision control.

According to a fourth aspect of the present invention, there is provided a control device for a power converter, wherein output voltages are equal in magnitude and each of them is 60 ° / n (n ≧
2) n phase-shift transformers having a phase difference, and n converters configured by bridge-connecting switching elements to convert AC power into DC power, and include n phase-shift transformers. The primary terminals are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of n converters in a one-to-one relationship, respectively. In a control device of a power conversion device including a power conversion main circuit that combines DC output and supplies DC power to a common DC load,
A current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detection value of the DC current flowing to the DC load; and obtaining a synchronization signal synchronized with the AC voltage from the AC power supply. Synchronization detection means, output current command vector generation means for generating an output current command vector of the power conversion device from a control amount of DC current and a synchronization signal obtained from the AC voltage, and all of the AC currents that the power conversion device can generate. An output current vector generating means for providing a current vector and a current vector diagram are converted into a phase angle of 60 ° / n in a phase angle of 0 to 360 °.
Divided into 6n phase division ranges from 1 to 6
a phase range number detecting means for detecting a phase range number in which the output current command vector generated by the output current command vector generating means exists, and an output generated by the output current vector generating means. Output current vector selecting means for selecting an output current vector corresponding to the current command vector generated by the output current command vector generating means from the current vectors, and selecting the selected output current vector according to the n converters a unit current vector distributing means for distributing the n unit current vectors, and an energizing phase of a converter arm corresponding to the phase range number detected by the phase range number detecting means when the distributed unit current vector generates a zero vector. Vector energization control means for controlling the zero current energization control unit current vector from the zero vector energization control means Depending characterized in that a transducer equipped with a means for controlling pulse width modulation.

In the case of the fourth aspect of the present invention, the zero vector is realized in a state where the upper and lower arms are short-circuited. In the case of a three-phase bridge connection converter, there are three different energized states depending on the number of phases. According to the phase angle of the vector, one of the conducting arms and one of the three energized phases that are the zero vector are selected so as to be common, and the phase shift condition of each converter (15 degrees in the case of a 24-phase configuration, In each case), unnecessary switching of the switching element is avoided to reduce the switching frequency by performing pulse width modulation control on the switching element.
Further, the zero vector energized phase can be equalized.

According to a fifth aspect of the present invention, there is provided a control device for a power converter, wherein output voltages have the same magnitude, and each of the output voltages is 60 ° / n (n ≧ n).
2) n phase-shifting transformers having a phase difference, n converters configured by bridging switching elements to convert AC power to DC power, and a reactor and DC connected in series to a DC load. And a DC filter including a capacitor connected in parallel to the load, wherein the primary terminals of the n phase-shift transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals Is a power source connected to the AC terminals of the n converters in a one-to-one relationship, and comprising a power conversion main circuit that combines the DC outputs of the n converters and supplies DC power to a common DC load. In the control device of the converter, a current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detection value of the DC current flowing to the DC load, and an AC voltage of the AC power supply. Get a sync signal that synchronizes with it Synchronous detection means, current detection means for detecting a capacitor current flowing through the capacitor of the DC filter, a low-pass filter for removing harmonic components of the detected capacitor current, and the output of the low-pass filter added to the control amount of the DC current Output current command vector generating means for generating an output current command vector of the power converter from the signal and the synchronization signal; output current vector generating means for providing all current vectors of the alternating current that can be generated by the power converter; output current vector Output current vector selecting means for selecting an output current vector corresponding to the current command vector generated by the output current command vector generating means from the output current vectors generated by the generating means; and selecting the output current vector by the output current vector selecting means. The output current vector is divided by n converters according to n converters. Position the unit current vector distribution means for distributing the current vector, characterized by comprising a means for pulse width modulation control converter according to the unit current vector.

According to the fifth aspect of the present invention, the current flowing into the capacitor of the DC filter is compensated by adding the capacitor current of the DC filter to the control amount of the DC current. The resonance component can be suppressed. By passing the detected value of the capacitor current through a first-order lag low-pass filter 31 for removing a harmonic component, the capacitor current of the DC filter 5 can be compensated without being affected by a switching frequency component. Can be improved in stability.

In the control device for a power converter according to claim 6, the magnitudes of the output voltages are equal, and each of the output voltages is 60 ° / n (n ≧ n).
2) n phase-shifting transformers having a phase difference, n converters configured by bridging switching elements to convert AC power to DC power, and a reactor and DC connected in series to a DC load. And a DC filter including a capacitor connected in parallel to the load, wherein the primary terminals of the n phase-shift transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals Is a power source connected to the AC terminals of the n converters in a one-to-one relationship, and comprising a power conversion main circuit that combines the DC outputs of the n converters and supplies DC power to a common DC load. In the control device of the converter, a current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detection value of the DC current flowing to the DC load, and an AC voltage of the AC power supply. Get a sync signal that synchronizes with it Synchronization detection means, DC voltage detection means for detecting the voltage of the DC load, and a signal obtained by adding a deviation of the detection voltage of the DC load with respect to the DC voltage command to the control amount of the DC current and a synchronization signal, and Output current command vector generating means for generating an output current command vector,
Output current vector generating means for providing all the current vectors of the alternating current that can be generated by the power conversion device; and a current command vector generated by the output current command vector generating means from the output current vectors generated by the output current vector generating means. Output current vector selecting means for selecting an output current vector according to the output current vector, and a unit current for distributing the output current vector selected by the output current vector selecting means to n unit current vectors according to n converters Vector distribution means and means for performing pulse width modulation control of the converter in accordance with the unit current vector are provided.

According to the present invention, in the case of a DC load composed of a reactor component and a resistance component, the DC current is a first-order delay of the DC voltage (a first-order delay determined by the reactor component and the resistance component). Therefore, by performing DC current control of the main loop with the DC voltage applied to the DC load settled by DC voltage control of the minor loop, the responsiveness of DC current control is improved, and high-precision control is achieved. Can be realized.

According to a seventh aspect of the present invention, there is provided the power conversion device control device according to the sixth aspect, wherein the DC current detection value input stage of the current control means includes the DC current detection value. And a low-pass filter for reducing harmonic components.

According to the seventh aspect of the invention, the detected value of the DC current is introduced into the current controller 11 through the low-pass filter, thereby changing the constant of the DC filter 5 provided in the main circuit (change of the cut-off frequency, Without changing the resonance value) or adding a filter to the main circuit, the harmonic components, mainly the resonance and switching components of the DC filter, are reduced, and unnecessary frequency components are not amplified by the current controller. ,
High precision control can be realized.

In the control device for a power conversion device according to the present invention, the magnitudes of the output voltages are equal and each of them is 60 ° / n (n ≧ n).
2) n phase-shifting transformers having a phase difference, n converters configured by bridging switching elements to convert AC power to DC power, and a reactor and DC connected in series to a DC load. And a DC filter including a capacitor connected in parallel to the load, wherein the primary terminals of the n phase-shift transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals Is a power source connected to the AC terminals of the n converters in a one-to-one relationship, and comprising a power conversion main circuit that combines the DC outputs of the n converters and supplies DC power to a common DC load. A control device for the conversion device, a first current control means for generating a control amount of the DC current from a difference between a command value of the DC current supplied to the DC load and a detected value of the DC current flowing to the DC load; Synchronous signal synchronized from AC voltage Means for obtaining a current vector of an AC current flowing between the primary terminals of the n phase-shift transformers and the AC power supply, and an output current of the power converter based on the control amount of the DC current and the synchronization signal. Output current command vector generating means for generating a command vector; AC current detecting means for obtaining a detection value of an AC current flowing between the primary terminals of the n phase-shift transformers and the AC power supply; A second current control unit that obtains an AC current command vector based on a current vector of the AC current, an output current vector generation unit that provides all current vectors of the AC current that can be generated by the power converter, and an output current vector generation unit. An output current vector that selects an output current vector corresponding to the AC current command vector obtained by the second current control means from the generated current vectors. Selecting means, unit current vector distributing means for distributing the output current vector selected by the output current vector selecting means into n unit current vectors according to the n converters, and converting according to the unit current vector Means for controlling pulse width modulation of the device.

According to the eighth aspect of the present invention, when the AC current becomes unbalanced due to fluctuations in the AC power supply, the control amount (compensation amount) of the AC current is obtained from the detected value of the AC current. Can be compensated for, and high-accuracy control that is hardly affected by the AC power supply condition can be achieved.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows an example of the configuration of a control device of a power converter according to a first embodiment of the present invention applied to the main circuit of FIG. The same circuit elements as those described above are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here.

The controller of FIG. 1 corresponds to the controller of FIG. 14 with the addition of a phase range number detector 17 and an output current vector detector 18 within the phase division range. As shown in FIG. 2, a distribution diagram (vector diagram) of the output current vector values generated by the output current vector generation circuit 14 is obtained by setting the phase angles 0 to 360 ° to 15 ° (n = 4) Each phase range is divided, and 24 phase division ranges are assigned phase range numbers of 1 to 24. The phase range number detector 17 selects, from the phase range numbers 1 to 24, a phase range number in which the output current command vector generated by the output current command vector generation circuit 12 exists. Output current vector detector 18 within the phase division range
Supplies the output current vector existing in the region of the phase range number selected by the phase range number detector 17 to the output current vector selection circuit 13 from the above-described vector diagram.
The output current vector selection circuit 13 outputs a desired output corresponding to the output current command vector generated by the output current command vector generation circuit 12 from the output current vectors detected by the output current vector detector 18 within the phase division range. Select a current vector.

According to the control device shown in FIG. 1, when selecting an output current vector corresponding to the output current command vector, a division range of 1/24 (when n = 4) corresponding to the phase angle of the output current command vector is selected. By selecting an output current vector from among them, the control operation time can be reduced to about 1/24, the follow-up performance can be improved, and high-precision control can be realized.

(Second Embodiment) FIG. 3 shows a configuration example of a second embodiment of the present invention applied to a control device of a current source converter, and has the same circuit elements as those in FIG. Are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here.

The control device of FIG. 3 is equivalent to the control device of FIG. 14 additionally provided with an amplitude range number detector 19 and an output current vector detector 20 within the amplitude division range. With reference to a distribution diagram (vector diagram) of output current vector values generated by the output current vector generator 14, as shown in FIG.
% / 4), and the four amplitude division ranges are assigned the amplitude range numbers of 1 to 4, and the amplitude range number detector 19 outputs the amplitude range number 1 The amplitude range number in which the output current command vector exists is selected from .about.4. The output current vector detector 20 within the amplitude division range supplies the output current vector selection circuit 13 with an output current vector existing in the area of the amplitude range number selected by the amplitude range number detector 19 from the above-described vector diagram. The output current vector selection circuit 13 outputs a desired output according to the output current command vector generated by the output current command vector generation circuit 12 from the output current vectors detected by the output current vector detector 20 within the amplitude division range. Select a current vector.

According to the control device shown in FIG. 3, when an output current vector corresponding to the output current command vector is selected, the output current vector is selected from within a 1/4 (n = 4) division range corresponding to the amplitude of the output current command vector. Since the vector is selected, the vector selection time, that is, the control calculation time can be reduced to about 1/4, and the follow-up property can be improved to realize high-precision control.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
In this embodiment, the same circuit elements as those shown in FIG. 14 are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here.

The control device of FIG. 5 is different from the control device of FIG. 14 in that a phase angle detector 21, a phase angle range detector 22, an amplitude detector 23, and an amplitude range detector 24 are additionally provided. Equivalent to. The phase angle detector 21 detects the phase angle θ at which the output current command vector generated by the output current command vector generation circuit 12 exists. The phase angle range detector 22 adds a hysteresis width ± △ θ to the phase angle θ detected by the phase angle detector 21, as shown in FIG.
Set the phase angle range θ ± △ θ. On the other hand, the amplitude detector 23
Detects the amplitude M at which the output current command vector exists. As shown in FIG. 6, the amplitude range detector 24
, A hysteresis width ± △ M is added, and an amplitude range M ± △ M is set. The output current vector selection circuit 13 surrounds a desired output current vector corresponding to the output current command vector generated by the output current command vector generation circuit 12 with a phase angle range θ ± △ θ and an amplitude range M ± △ M. Selected from the specified narrow area and output.

According to the control device shown in FIG. 5, when an output current vector corresponding to the output current command vector is selected, an output current vector close to the output current command vector is selected into a range in which the hysteresis width is taken into account for the phase angle and amplitude. Since the output current vector is selected from among them, the output current vector can be selected at high speed, and the follow-up performance can be improved to realize high-accuracy control.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment of the present invention.
In this embodiment, the same circuit elements as those shown in FIG. 14 are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here. FIG.
9 is an explanatory diagram of the operation of the control device of FIG.

The control device of FIG. 7 corresponds to a control device in which a phase range number detector 25 and a zero vector energization control circuit 26 are additionally provided to the control device of FIG. As shown in FIGS. 8 and 9, the distribution diagrams (vector diagrams) of the output current command vector values generated by the output current command vector generation circuit 12 are shown in FIG. 4)
And the 24 phase division ranges are 1 to 2
Assuming that a phase range number of 4 is assigned, the phase range number detector 25 detects the phase range numbers 1 to 24 in which the output current command vector generated by the output current command vector generation circuit 12 exists. Zero vector energization control circuit 26
When the unit current vector distribution circuit 15 selects “zero vector” as the unit current vector, the current phase corresponding to any of the phase range numbers 1 to 24 is selected.

The "zero vector" is realized in a state where the upper and lower arms (see FIG. 16) are short-circuited. In the case of a three-phase bridge connection, actually, three types (U- There may be an energized state of the X arm, VY arm, WZ arm). According to the phase angle of the output current command vector, one of the two conducting arms and one of the three energizing arms that become the zero vector are common,
Control the energizing arm.

FIG. 8 shows a unit current vector diagram in the case of a converter (3a) connected to a phase shift transformer having a phase shift of 0 ° (for example, a phase shift transformer 2a). For example, when the phase angle of the output current command vector is 0 ° (phase range number 1), the unit current vector exists between the energizing arms of the U and Z arms or the U and Y arms (phase range numbers 23 to 3). . If the “zero vector” is selected during this time, the “UX phase” having the “U arm” that is common to the unit current vectors U, Z arm and U, Y arm is determined as the energized phase. Similarly, in each range of the phase angle of 0 ° to 360 ° (phase range numbers 1 to 24), the combination of the energized phases of “zero vector” can be determined.

FIG. 9 shows a unit current vector diagram in the case of a converter connected to a phase shift transformer of 15 ° phase shift.
In this case, the output current command vector is represented by a vector diagram obtained by shifting the unit current vector diagram shown in FIG. 8 by 15 ° with respect to the phase angle 0 ° (phase range number 1). Can be uniquely determined from the above combinations. In the case of a converter connected to a phase shift transformer having a phase shift of 30 ° and 45 °, the energized phase can be determined in the same manner.

As described above, when one of the energizing arms is selected when the zero vector is selected, unnecessary switching of the switching element is avoided to reduce the switching frequency, and the zero vector energizing phase is selected according to the phase angle. Thereby, the energization pattern can be equalized.

(Fifth Embodiment) FIG. 10 shows a configuration example of a fifth embodiment of the present invention applied to the main circuit of FIG. 15, and the same circuit elements as those of FIG. The same reference numerals are given and the description is omitted, and only different portions will be described here.

The control device shown in FIG. 10 corresponds to a device obtained by adding a capacitor current detector 30 and a first-order lag low-pass filter 31 to the control device shown in FIG. The capacitor current detector 30 detects a value of a current flowing through the capacitor 5b of the DC filter 5. The low-pass filter 31 is mathematically expressed as K / (1 + sT), where K is a constant and T is time.
And removes the high-frequency switching frequency component included in the detected value of the detected capacitor current, and adds it to the output control amount of the current controller 11, whereby the DC filter 5 compensates for the amount of current flowing into the capacitor 5b.

By compensating the amount of current flowing through the capacitor 5b in this manner, the resonance component due to the reactor 5a and the capacitor 5b constituting the DC filter 5 can be suppressed. Further, by adding a first-order lag low-pass filter 31 for removing the switching frequency component to the detected value of the capacitor current, the DC filter 5 can be prevented from being disturbed by the high-frequency switching frequency component.
Can be compensated for, and the stability of control can be improved.

(Sixth Embodiment) FIG. 11 shows a configuration example of a fifth embodiment of the present invention, and the same circuit elements as those in FIG. 15 or FIG. The description thereof will be omitted, and only different portions will be described here.

The control device of FIG. 11 is different from the control device of FIG. 15 in that the DC voltage detector 32 and the voltage controller (AVR) 3
3 corresponds to an additional arrangement. Voltage controller 33
Is provided as a component of a minor loop formed in a main loop of DC current control constituted by the current controller 11 and below, and includes a DC voltage command Vd ^* and a DC voltage detected by the DC voltage detector 32. A current command vector control amount is generated based on a signal obtained by adding a difference from the detected value of Vd, that is, a DC voltage deviation component to an output control amount of the current controller 11, and is sent to an output current command vector generation circuit 12. The DC load 6 is, as shown by the symbol,
When the DC current Id is composed of the reactor component (L) and the resistance component (R), the DC current Id is a first-order delay of the DC voltage Vd (the first-order delay determined by the reactor component L and the resistance component R: I
Since d = (Vd / (R + sL)), higher-speed current control can be performed by performing control in accordance with the DC voltage Vd applied to the DC load 6. That is, by providing the DC voltage control loop of the minor loop, the responsiveness of DC current control of the main loop can be improved, and high-precision control can be realized.

(Seventh Embodiment) FIG. 12 shows a configuration example of the seventh embodiment of the present invention. The same circuit elements as those in FIG. Are omitted, and only different portions will be described here.

The control device of FIG. 12 is equivalent to the control device of FIG. 11 except that a second-order lag low-pass filter 34 is provided at the output stage of the DC current detector 7. The second-order lag low-pass filter 34 is useful for reducing a harmonic component mainly including a switching frequency component included in a detection value of the DC current detector 7. Although a second-order lag low-pass filter can be used as the low-pass filter 34, a similar effect or an improvement in control response can be achieved by using a notch filter instead.

By providing the low-pass filter 34, the DC filter 5 provided in the main circuit can be changed without changing the constants (change of cutoff frequency, change of resonance value, etc.) or adding a filter to the main circuit. The harmonic component mainly including the resonance component and the switching component of No. 5 can be reduced, and unnecessary amplification of the frequency component in the current controller 11 can be avoided.

(Eighth Embodiment) FIG. 13 shows a configuration example of an eighth embodiment of the present invention. The same circuit elements as those in FIG. Are omitted, and only different portions will be described here.

The control device shown in FIG. 10 is different from the control device shown in FIG. 15 in that an AC current detector 35 for detecting the input current of the power converter viewed from the AC power supply 1, a three-phase two-phase (vector) conversion circuit 36, And a second current controller (ACR) 37 is additionally provided. The AC current detector 35
A three-phase AC current flowing between the primary terminals of the phase-shift transformers 2a to 2d (n = 4) and the AC power supply 1 is detected, and the detected value of the AC current is converted into a three-phase two-phase (vector) conversion circuit 36. Converts into a two-phase current vector value of the alternating current. The difference obtained by subtracting this current vector value from the output current command vector generated by the output current command vector generation circuit 12, that is, the difference between the two, is introduced as a compensation amount into the current controller 37, where the control amount of the AC current is generated. I do.

According to this embodiment, even when an imbalance occurs in the AC current due to AC power supply fluctuation or the like, the compensation amount of the AC current is obtained from the detected value of the AC current and is compared with the AC current command vector. Thereby, the unbalanced portion of the alternating current can be compensated.

(Modifications to First to Eighth Embodiments) (Part 1) In the above description, the 24-phase configuration (n =
Although the case of 4) has been described, the present invention is not limited to a 24-phase configuration, and two sets of multiple connections in the case of a number of phases exceeding 12 phases or 24 phases or multiple connections of a 24-phase configuration or the like are provided. The same effect can be applied to the case of the parallel connection as described above.

(2) In the above description, one set of self-extinguishing type switching elements is used for each arm of the bridge circuit. However, the number of series-connected elements in accordance with the voltage and current ratings of the circuit is described. Alternatively, the number of parallel connections can be appropriately considered.

(Part 3) In the above description, an example of the circuit configuration of the three-phase bridge connection is shown. However, the present invention is not limited to the three-phase bridge connection. It can also be applied to connection circuits.

(Part 4) In the above-described embodiment, an example of a configuration for each claim has been described. However, the present invention is not limited to the configuration for each claim, and uses a combination of the configurations for each claim. The same effect or a synergistic effect can be achieved.

[0067]

As described in detail above, according to the present invention,
In the pulse width modulation control based on the space vector, the time for selecting the current command vector, that is, the control calculation time can be reduced, and high-precision control can be realized at a low switching frequency.

Further, according to the present invention, even when a DC filter is provided on the output side of the power converter, the pulse width modulation control using the space vector can be performed at a low switching frequency with good stability and good tracking. It can be realized with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a first embodiment of a control device of a power conversion device according to the present invention.

FIG. 2 is an explanatory diagram of an output current command vector in the control device of FIG. 1;

FIG. 3 is a block diagram showing a main part of a control device for a power conversion device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of an output current command vector in the control device of FIG. 3;

FIG. 5 is a block diagram showing a main part of a third embodiment of the control device for the power conversion device according to the present invention.

6 is an explanatory diagram of an output current command vector in the control device of FIG.

FIG. 7 is a block diagram showing a main part of a fourth embodiment of the control device of the power converter according to the present invention.

FIG. 8 is an explanatory diagram of an output current command vector in the case of a converter connected to a specific phase shift transformer in the control device of FIG. 7;

9 is an explanatory diagram of an output current command vector in the case of a converter connected to another phase shift transformer in the control device of FIG. 7;

FIG. 10 is a block diagram showing a fifth embodiment of the control device of the power converter according to the present invention.

FIG. 11 is a block diagram showing a sixth embodiment of the control device of the power converter according to the present invention.

FIG. 12 is a block diagram showing a seventh embodiment of the control device of the power converter according to the present invention.

FIG. 13 is a block diagram showing an eighth embodiment of the control device of the power converter according to the present invention.

FIG. 14 is a main circuit connection diagram and a block diagram of a control device showing a first configuration example of a conventional control device for a power conversion device.

FIG. 15 is a main circuit connection diagram and a block diagram of a control device showing a second configuration example of the control device of the conventional power converter.

FIG. 16 is a circuit connection diagram of a unit converter constituting the converter group shown in FIGS. 14 and 15;

FIG. 17 is an explanatory diagram illustrating a unit current vector that can be generated.

18 is a time chart showing the energized state and output current of each arm shown in FIG.

FIG. 19 is a current vector diagram for explaining selectable vectors.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 2 Phase shift transformer group 2a-2d Unit phase shift transformer (phase shift transformer) 3 Converter group 3a-3d Unit converter (converter) 4u-4z Semiconductor switching element 5 DC filter 5a Reactor 5b Capacitor 5c Resonance suppression resistor 6 DC load 7 Current detector 8 Voltage detector 9 Synchronous detection circuit 10 DC current command generation circuit 11 Current controller (ACR) 12 Output current command vector generation circuit 13 Output current vector selection circuit 14 Output current vector generation Circuit 15 Unit current vector distribution circuit 16 Gate signal generation circuit 17 Phase range number detector 18 Output current vector detector within phase division range 19 Amplitude range number detector 20 Output current vector detector within amplitude division range 21 Phase angle detector 22 Phase angle range detector 23 Amplitude detector 24 Amplitude range detector 25 Phase Enclosure number detector 26 Zero vector energization control circuit 30 Capacitor current detector 31 Primary delay low-pass filter 32 DC voltage detector 33 DC voltage controller (AVR) 34 Secondary delay circuit 35 AC current detector 36 3 phase 2 phase ( Vector) conversion circuit 37 Current controller (ACR)

Claims (8)

[Claims] The output voltages are equal in magnitude and each is 60 ° / n.
N switching transformers having a phase difference of (n ≧ 2), and n converters configured by bridge-connecting switching elements to convert AC power to DC power. The primary terminals of the phase transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of the n converters in a one-to-one relationship, respectively. n
A control device for a power conversion device including a power conversion main circuit that combines the DC outputs of two converters and supplies DC power to a common DC load, wherein a command value of a DC current supplied to the DC load and the DC Current control means for generating a control amount of the DC current from a difference between the detected value of the DC current flowing to the load, synchronization detection means for obtaining a synchronization signal synchronized with the AC voltage from the AC voltage of the AC power supply, and a control amount of the DC current Output current command vector generating means for generating an output current command vector of the power conversion device from the synchronization signal obtained from the AC voltage, and an output current vector for providing all current vectors of the AC current that the power conversion device can generate. Generating means and a current vector diagram are divided into a phase range of 60 ° / n within a phase angle of 0 to 360 °,
Phase range number detecting means for detecting a phase range number in which the output current command vector generated by the output current command vector generating means exists when 6n phase division ranges are assigned phase range numbers of 1 to 6n; A phase division range output current vector for detecting a current vector within a phase division range corresponding to the phase range number detected by the phase range number detection means from among the output current vectors generated by the output current vector generation means. Detecting means;
Output current vector selection means for selecting an output current vector according to the output current command vector from within the detected phase division range; and converting the output current vector selected by the output current vector selection means into the n units A power supply device comprising: a unit current vector distribution means for distributing the current to n unit current vectors according to the unit; and a means for controlling the pulse width modulation of the converter in accordance with the unit current vector. Control device. 2. The output voltages are equal in magnitude and each of them is 60 ° / n.
N switching transformers having a phase difference of (n ≧ 2), and n converters configured by bridge-connecting switching elements to convert AC power to DC power. The primary terminals of the phase transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of the n converters in a one-to-one relationship, respectively. n
A control device for a power conversion device including a power conversion main circuit that combines the DC outputs of two converters and supplies DC power to a common DC load, wherein a command value of a DC current supplied to the DC load and the DC Current control means for generating a control amount of the DC current from a difference between the detected value of the DC current flowing to the load, synchronization detection means for obtaining a synchronization signal synchronized with the AC voltage from the AC voltage of the AC power supply, and a control amount of the DC current Output current command vector generating means for generating an output current command vector of the power conversion device from the synchronization signal obtained from the AC voltage, and an output current vector for providing all current vectors of the AC current that the power conversion device can generate. It is assumed that the generation means and the current vector diagram are divided into amplitude ranges of 100% / n among the current vector amplitudes of 0 to 100%, and n amplitude division range numbers are assigned. An amplitude range number detecting means for detecting an amplitude range number in which the output current command vector generated by the output current command vector generating means exists; and an output current vector generated by the output current vector generating means, An output current vector detector within the amplitude division range for detecting a current vector within the amplitude division range corresponding to the amplitude range number detected by the amplitude range number detection unit, and the output current command vector from the detected amplitude division range. An output current vector selecting means for selecting an output current vector according to the output current vector, and the output current vector selected by the output current vector selecting means is distributed to n unit current vectors according to the n converters. A unit current vector distributing means for performing pulse width modulation control on the converter in accordance with the unit current vector; Control system for a power conversion apparatus characterized by comprising a means. 3. The output voltages are equal in magnitude and each of them is 60 ° / n.
N switching transformers having a phase difference of (n ≧ 2), and n converters configured by bridge-connecting switching elements to convert AC power to DC power. The primary terminals of the phase transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of the n converters in a one-to-one relationship, respectively. n
A control device for a power conversion device including a power conversion main circuit that combines the DC outputs of two converters and supplies DC power to a common DC load, wherein a command value of a DC current supplied to the DC load and the DC Current control means for generating a control amount of the DC current from a difference between the detected value of the DC current flowing to the load, synchronization detection means for obtaining a synchronization signal synchronized with the AC voltage from the AC voltage of the AC power supply, and a control amount of the DC current Output current command vector generating means for generating an output current command vector of the power conversion device from the synchronization signal obtained from the AC voltage, and an output current vector for providing all current vectors of the AC current that the power conversion device can generate. Generating means, phase angle detecting means for detecting the phase angle of the output current command vector generated by the output current command vector generating means, A phase angle range detecting means for setting a phase angle range by providing a hysteresis width, and detecting a current vector included in the phase angle range from output current vectors generated by the output current vector generating means; and Amplitude detection means for detecting the amplitude of the output current command vector generated by the command vector generation means, and an amplitude range set by providing a hysteresis width to the detected amplitude; and an output current vector generated by the output current vector generation means. An amplitude range detecting means for detecting a current vector included in the amplitude range from among the following: a phase angle range of the current vector detected by the phase angle range detecting means; and an amplitude of the current vector detected by the amplitude range detecting means. Output current vector selection for selecting one current vector from the overlapping area A stage, unit current vector distribution means for distributing the output current vector selected by the output current vector selection means into n unit current vectors according to the n converters, Means for controlling the converter with pulse width modulation. 4. The output voltages are equal in magnitude and each of them is 60 ° / n.
N switching transformers having a phase difference of (n ≧ 2), and n converters configured by bridge-connecting switching elements to convert AC power to DC power. The primary terminals of the phase transformers are connected in common and connected in parallel to a common AC power supply, and the secondary terminals are connected to the AC terminals of the n converters in a one-to-one relationship, respectively. n
A control device for a power conversion device including a power conversion main circuit that combines the DC outputs of two converters and supplies DC power to a common DC load, wherein a command value of a DC current supplied to the DC load and the DC Current control means for generating a control amount of the DC current from a difference between the detected value of the DC current flowing to the load, synchronization detection means for obtaining a synchronization signal synchronized with the AC voltage from the AC voltage of the AC power supply, and a control amount of the DC current Output current command vector generating means for generating an output current command vector of the power conversion device from the synchronization signal obtained from the AC voltage, and an output current vector for providing all current vectors of the AC current that the power conversion device can generate. Generating means and a current vector diagram are divided into a phase range of 60 ° / n within a phase angle of 0 to 360 °,
Phase range number detecting means for detecting a phase range number in which the output current command vector generated by the output current command vector generating means exists when 6n phase division ranges are assigned phase range numbers of 1 to 6n; Output current vector selecting means for selecting an output current vector corresponding to the current command vector generated by the output current command vector generating means from among the output current vectors generated by the output current vector generating means; A unit current vector distribution means for distributing an output current vector into n unit current vectors according to the n converters, and a phase range number detection means when the distributed unit current vector produces a zero vector Zero vector energization control means for controlling the energization phase of the converter arm corresponding to the phase range number, Control system for a power conversion apparatus characterized by comprising a means for pulse width modulation controlling the converter according to the unit current vector from zero vector current control means. 5. The method according to claim 1, wherein the magnitudes of the output voltages are equal,
N phase-shift transformers having a phase difference of (n ≧ 2), switching elements are bridge-connected, and n converters for converting AC power to DC power are connected in series to a DC load. A DC filter including a reactor and a capacitor connected in parallel to the DC load, wherein primary terminals of the n phase-shift transformers are commonly connected and connected in parallel to a common AC power supply; , The secondary terminals are respectively connected to the AC terminals of the n converters in a one-to-one relationship, and the DC outputs of the n converters are combined to supply DC power to a common DC load. In a control device for a power converter including a conversion main circuit, a current control for generating a control amount of a DC current from a difference between a command value of a DC current supplied to the DC load and a detection value of a DC current flowing to the DC load. Means and an AC of the AC power supply Synchronization detection means for obtaining a synchronization signal synchronizing with the voltage, current detection means for detecting a capacitor current flowing through the capacitor of the DC filter, a low-pass filter for removing harmonic components of the detected capacitor current, and the DC current Output current command vector generation means for generating an output current command vector of the power conversion device from a signal obtained by adding the output of the low-pass filter to the control amount of the control signal and the synchronization signal, and all of the AC currents that the power conversion device can generate. Output current vector generating means for providing a current vector of the following, and an output current vector corresponding to the current command vector generated by the output current command vector generating means is selected from the output current vectors generated by the output current vector generating means. Output current vector selecting means, and the output current vector Unit current vector distribution means for distributing the output current vector selected by the selection means to n unit current vectors according to the n converters; and controlling the converter to have a pulse width in accordance with the unit current vector. A control device for a power conversion device, comprising: means for performing modulation control. 6. The output voltages having the same magnitude and each of 60 ° / n
N phase-shift transformers having a phase difference of (n ≧ 2), switching elements are bridge-connected, and n converters for converting AC power to DC power are connected in series to a DC load. A DC filter including a reactor and a capacitor connected in parallel to the DC load, wherein primary terminals of the n phase-shift transformers are commonly connected and connected in parallel to a common AC power supply; , The secondary terminals are respectively connected to the AC terminals of the n converters in a one-to-one relationship, and the DC outputs of the n converters are combined to supply DC power to a common DC load. In a control device of a power converter including a conversion main circuit, a current control for generating a control amount of a DC current from a difference between a command value of a DC current supplied to the DC load and a detected value of a DC current flowing to the DC load. Means and an AC of the AC power supply Synchronization detection means for obtaining a synchronization signal synchronizing therewith from voltage, DC voltage detection means for detecting the voltage of the DC load, and the control amount of the DC current, the deviation of the detection voltage of the DC load with respect to the DC voltage command Output current command vector generation means for generating an output current command vector of the power conversion device from the added signal and the synchronization signal; and output current vector generation means for providing all current vectors of the alternating current that can be generated by the power conversion device Output current vector selecting means for selecting an output current vector corresponding to a current command vector generated by the output current command vector generating means from output current vectors generated by the output current vector generating means; and The output current vector selected by the current vector selection means is changed according to the n converters. Controller of the power converter, wherein the unit current vector distribution means for distributing the number of unit current vector, that and means for pulse width modulation controlling the converter according to the unit current vector. 7. The control device for a power conversion device according to claim 6, wherein a low-pass filter for reducing a harmonic component included in the detected value of the DC current is provided to an input stage of the detected value of the DC current of the current control means. A control device for a power conversion device, comprising: 8. The output voltages having the same magnitude and each of 60 ° / n
N phase-shift transformers having a phase difference of (n ≧ 2), switching elements are bridge-connected, and n converters for converting AC power to DC power are connected in series to a DC load. A DC filter including a reactor and a capacitor connected in parallel to the DC load, wherein primary terminals of the n phase-shift transformers are commonly connected and connected in parallel to a common AC power supply; , The secondary terminals are respectively connected to the AC terminals of the n converters in a one-to-one relationship, and the DC outputs of the n converters are combined to supply DC power to a common DC load. In the control device for a power conversion device including a conversion main circuit, a first control unit that generates a DC current control amount from a difference between a command value of a DC current supplied to the DC load and a detected value of a DC current flowing to the DC load. Current control means and the AC power supply Synchronizing detecting means for obtaining a synchronizing signal synchronizing with the AC voltage from the AC voltage, means for obtaining a current vector of an AC current flowing between the primary terminals of the n phase-shift transformers and an AC power supply, and a control amount of the DC current Output current command vector generating means for generating an output current command vector of the power converter from the synchronization signal and the synchronization signal; and detecting an AC current flowing between a primary terminal of the n phase-shift transformers and an AC power supply. AC current detecting means for obtaining a value, second current control means for obtaining an AC current command vector based on the output current command vector and the current vector of the AC current, and all of the AC currents which can be generated by the power converter. An output current vector generating means for providing a current vector; and a current vector generated by the second current control means from among the current vectors generated by the output current vector generating means. An output current vector selecting means for selecting an output current vector corresponding to the alternating current command vector,
A unit current vector distribution unit that distributes the output current vector selected by the output current vector selection unit into n unit current vectors according to the n converters, and the conversion according to the unit current vector Means for controlling pulse width modulation of the converter.