JP3193210B2 - Power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter which uses a forward converter, has a resistance chopper device on the DC output side, and further connects a linear motor as a load of the reverse converter.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a schematic configuration of a conventional power conversion device of this kind, in which AC power from an AC power system 1 is converted into DC power via a transformer 2 for a forward converter. An apparatus (converter) 3 is connected, and a DC reactor 4 for reducing ripples is provided on the output side of the forward converter 3. DC power is supplied to the DC output side by a resistor 6 connected via a semiconductor switch. Chopper device 5 to consume
And a power capacitor 7 for a voltage-type inverter connected to a DC system, an inverter (inverter converter) 8 capable of performing forward and reverse conversion operations, and an AC power supply to a load system 10 via a transformer 9 for an inverter converter. I am trying to do it.

Further, current detectors 11, 12, and 13 for controlling each device (each converter) 3, 5, and 8, and a DC voltage detector 14 are provided.

The control characteristics of each of the devices 3, 5, 8 in such a power converter will be described.

FIG. 6 shows the characteristics of a general forward conversion device 3. When the vertical axis is DC voltage and the horizontal axis is DC current, the control angle α is determined by the AC system voltage and the impedance of the transformer for the converter. It has a constant control characteristic, a constant voltage characteristic for making the DC voltage constant by the constant voltage control system, and a constant current characteristic for performing the DC voltage droop by the constant current control system to prevent an overload of the forward converter 3.

FIG. 7 shows the characteristics of the resistance chopper device 5.
When the ordinate represents the DC voltage and the abscissa represents the chopper current, the characteristics of the resistor 6, the constant voltage characteristic for making the DC voltage constant by the constant voltage control system, and the voltage reference value of the constant voltage control system Is set several% higher than the voltage reference value. Further, a DC current control characteristic of the forward converter 3 by a constant current control system,
Each of the operating characteristics of the chopper device 5 is determined by the conduction angle minimum characteristic, the constant voltage characteristic, and the conduction angle maximum characteristic.

FIG. 8 shows the characteristics of the inverter 8, where the vertical axis represents the DC voltage and the horizontal axis represents the inverter current. Assuming that the load is constant, the power passing through the inverter 8 becomes constant. , The forward conversion operation characteristic (during power running) and the inverse conversion operation characteristic (during regeneration) are hyperbolic.

Next, the overall control coordination of the power converter of FIG. 5 will be described with reference to FIGS. The base value of the current value is based on the capacity of the forward conversion device 3.

FIG. 9 shows a state in which the inverter 8 is in a power running state. When the vehicle starts running and the inverter current is less than 10% and the vehicle is running, the operating points of the devices 3, 5, and 8 are (1). When driven, the resistance chopper device 5 is operated under current control, and the forward conversion device 3 is operated.
Is controlled to flow by 10%.

The forward converter 3 controls the DC voltage to be constant by DC voltage control. The speed increases and the inverter current becomes about 10% and the operating point (2)
Then, when the speed rises and the inverter current becomes 10% or more and reaches the operating point (3), the resistance chopper device 5 is shifted to the stop state, and all the inverter current is supplied from the forward converter 3. When the vehicle approaches the destination and reduces the speed, the inverter current becomes about 10%. When the inverter current further decreases, the resistance chopper device 5 is shifted to the operation state, and the operation points (2) and (1) are established, and the forward conversion device is set. 3 is controlled so that 10% of the current flows, and the increase / decrease of the inverter current is absorbed by the resistance chopper device 5.

On the other hand, FIG. 10 shows a state in which the inverter is in the regenerative operation state. Immediately after the vehicle brake is activated and the regenerative operation is started, the forward conversion device 3 is operating.
The operating points of 5, 8 are (1), and the current of the forward converter 3 is 1
It is controlled by the resistance chopper device 5 so that 0% flows.

Next, the forward conversion device 3 shifts to a stop state,
The operating point (2) is reached, and the resistance chopper device 5 has a value several% higher than the DC voltage control reference value of the forward converter 3 (for example, 103%).
Is controlled by a constant voltage characteristic with DC voltage control reference value,
The DC voltage is controlled by the resistance chopper device 5 so that the regenerative current flows through the resistor 6. The increase or decrease in the regenerative current is absorbed by the resistance chopper device 5. To the operating state, and the operating point (3)
Becomes

In order to perform the cooperative control described above, the resistance chopper device 5 performs control according to a signal control block diagram shown in FIG.

The components having the same reference numerals as those in FIG. 5 have the same configuration, and a description thereof will be omitted. The output signal of the current detector 11 for detecting the current of the forward converter 3 and the output signal of the current detector 13 for detecting the current flowing through the inverse converter 8 are input to adders 47 and 48, respectively.

During the power running operation, the output signal of the current setting circuit (1) 40 and the current flowing through the forward converter 3 are added by an adder 47, and the current having the same value as the current set value flows. The signal is input to a level detection circuit (LD) 42 to be output.
44 becomes one side signal. The other signal of the AND circuit 44 receives the operation state signal of the inverter 8 and becomes "1" level during the power running operation.

The AND circuit 44 determines the state of each input signal and outputs a signal for operating or stopping the resistance chopper device 5.

The output signal of the current setting circuit (2) 41 and the current flowing through the inverse converter 8 are added by an adder 48, and a level detection circuit (which outputs when the current having the same value as the current setting value flows) is output. LD) 43 and the level detection circuit 43
Is a signal on one side of an AND circuit (logical product circuit) 45. An operation state signal of the inverter 8 is input to the other signal of the AND circuit 45, and the signal becomes “0” level by the NOT circuit (logical NOT circuit) 46 during the power running operation.

The AND circuit 45 determines the state of each input signal and outputs a signal for operating or stopping the forward converter 3.

Next, a control device of the resistance chopper device 5 will be described.

FIG. 11 shows a general control block diagram.
The output signal of the current detector 11 for detecting the current of the forward converter 3 and the output signal of the current reference circuit 21 are inverted by an adder 27 and added, and the sum is input to the constant current control circuit 23. 3 is controlled. The output signal of the DC voltage detector 14 for detecting the DC voltage and the voltage reference circuit 20
The output signal is inverted by an adder 26 and added, and is input to the constant voltage control circuit 22 to control the DC voltage to be constant.

Further, a limiter circuit 24 for determining the maximum and minimum conduction angles of the resistance chopper device 5 is provided.
The outputs of 2, 23 and 24 are input to a control signal selection circuit 25 so that the control characteristics shown in FIG. 7 can be obtained.

[0022]

[0009] In the power converter having the above-described structure, when the control cooperative operation is performed, the power converter shown in FIG.
When the power running current of the inverter conversion device 8 becomes about 10%, the resistance chopper device 5 is in the operation state at the minimum conduction angle, and when the resistance chopper device 5 stops, the forward conversion device 3 is turned off. Since the flowing current decreases to 10% or less, the resistance chopper device 5 is operated again in the control device, so that the operation and the stop are repeated in the operation region near 10%.

On the other hand, when the inverter converter 8 is in the regenerative operation state, the vehicle brake is applied, and as shown in FIG. 10, immediately after the regenerative operation is started, the forward converter 3 is operated.
The current of the forward converter 3 is controlled to flow by 10%.

Next, the forward conversion device 3 shifts to a stop state,
The resistance chopper device 5 controls by a constant voltage characteristic in which a value (for example, 103%) higher than the DC voltage control reference value of the forward conversion device 3 by several percent (for example, 103%) is set as the DC voltage control reference value, and the DC voltage is controlled by the resistance chopper device 5. Thus, the regenerative current flows through the resistor 6.

The increase or decrease of the regenerative current is absorbed by the resistance chopper device 5, and if the regenerative power from the inverter 8 is equal to or less than the power at the time of the minimum conduction angle operation of the resistance chopper device 5, the DC voltage decreases. In order to prevent this voltage drop, the forward converter 3
Is operated, but there is a problem that the forward conversion device 3 is repeatedly operated and stopped in this region.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power converter capable of stably operating without continuously operating and stopping the resistance chopper device or the forward converter.

[0027]

In order to achieve the above object, an invention according to claim 1 comprises a forward converter for converting AC power into DC power, and a DC switch on the DC output side. And a reverse converter that supplies AC power obtained by a reverse conversion operation connected to a DC system, wherein the forward converter has a constant voltage characteristic. By
Control means for controlling the forward conversion operation characteristics of the inverse conversion device
Control means for controlling the resistance chopper device and the resistance chopper device.
Control means for controlling by a current characteristic, and when the inverting device is in power running operation, an output current of the forward converting device is detected, and a preset current control of the resistance chopper device is performed.
A first current detecting means for detecting that the current value has become equal to or greater than a first current set value corresponding to the current reference value, and a detection signal from the first current detecting means is inputted to the resistance chopper device. Current correction means for correcting the current reference value by adding a current correction value to the current reference value of the current control, and detecting the output current of the forward converter and correcting the current of the resistance chopper device corrected by the current correction means. Corresponds to the control current reference value
Second detecting that it is now more than a second current set value
When the detection signal from the current detecting means and the second current detecting means is inputted, the resistance chopper device is stopped,
Means for canceling the correction by the current correcting means.

According to another aspect of the present invention, there is provided a forward converter for converting AC power into DC power, and a resistor having DC power connected to the DC output side via a semiconductor switch. In a power conversion device comprising a resistance chopper device which is consumed by a DC power supply and an inverter which is connected to a DC system and supplies AC power obtained by an inverse conversion operation, a control means for controlling the forward converter by a constant voltage characteristic.
Controlling the stage and the inverse transform device by inverse transform operating characteristics
Controlling means and the resistance chopper device by a constant voltage characteristic.
A control means for controlling, and a third detecting means for detecting an input current of the inverting device when the inverting device is in a regenerative operation, and detecting that the input current has become equal to or more than a preset third current set value. When the detection signal from the current detection means and the detection signal from the third current detection means is input, the forward conversion device is stopped ,
The resistance chopper device is connected to a voltage base of the voltage control of the forward converter.
A first operating means for controlling the voltage by a voltage reference value higher than the reference value, and a fourth current setting value smaller than a third current setting value detected by detecting an input current of the inverter. Power conversion device comprising: a fourth current detection means for detecting that the power supply has become inactive; and a second operation means for operating the forward conversion device when a detection signal is input from the fourth current detection means. Device.

According to a third aspect of the present invention, there is provided a forward converter for converting AC power into DC power, and a resistor having DC power connected to the DC output side via a semiconductor switch. In a power conversion device comprising a resistance chopper device which is consumed by a DC power supply and an inverter which is connected to a DC system and supplies AC power obtained by an inverse conversion operation, a control means for controlling the forward converter by a constant voltage characteristic.
Controlling the stage and the inverse conversion device by a forward conversion operation characteristic
The control means and the inverse conversion device are controlled by inverse conversion operation characteristics.
Control means for controlling the resistance chopper device with a constant current characteristic.
Control means for controlling the resistance chopper device and the resistance chopper device.
A control means for controlling by a voltage characteristic, and a current control of the resistance chopper device which is set in advance by detecting an output current of the forward conversion device when the reverse conversion device is in a power running operation.
A first current detecting means for detecting that the current value has become equal to or greater than a first current set value corresponding to the current reference value, and a detection signal from the first current detecting means is inputted to the resistance chopper device. Current correction means for adding a current correction value to the current reference value of the current control to correct the current reference value, and detecting the output current of the forward converter and correcting the current of the resistance chopper device corrected by the current correction means. Corresponds to the control current reference value
Second detecting that it is now more than a second current set value
When the detection signal from the current detecting means and the second current detecting means is inputted, the resistance chopper device is stopped,
Means for canceling the correction by the current correction means, and when the inverter is in regenerative operation, detects the input current of the inverter and is equal to or greater than a preset third current set value. And when a detection signal from the third current detection means is input, the forward conversion device is stopped, and the resistance chopper device is changed to the forward conversion state.
Voltage reference value higher than the voltage reference value of
A first operating means for further controlling the voltage and an input current of the inverting device, wherein the input current is detected to detect that the current has become equal to or less than a fourth current set value which is smaller than a preset third current set value. 4 is a power conversion device comprising: a current detection unit of No. 4; and a second operation unit for operating the forward conversion device when a detection signal from the fourth current detection unit is input.

[0030]

According to the invention corresponding to the first aspect, when the reverse conversion device is operating at a powering current of about 10%, and when the resistance chopper device is stopped, the direct current is interrupted or interrupted in the forward conversion device. Unnecessary operation and stop of the resistance chopper device are not repeatedly performed.

According to the invention corresponding to claim 2, the forward conversion is performed even when the regenerative power is lower than the power consumed at the minimum conduction angle of the resistance chopper device when the inverter is in regenerative operation. Unnecessary operation and stop of the device are not repeated.

According to the third aspect of the present invention, when the reverse conversion device is running at a powering current of about 10% and the resistance chopper device is stopped, the direct current is interrupted or interrupted in the forward conversion device. Unnecessary operation and stop of the resistance chopper device are prevented from being repeatedly performed, and when the inverting device is performing regenerative operation, the amount of regenerative power is smaller than the power consumed at the minimum conduction angle of the resistance chopper device. Unnecessary operation and stoppage of the forward conversion device is not repeated even when it is lowered.

[0033]

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

FIG. 1 is a block diagram showing a main part of an embodiment of the present invention, that is, a schematic configuration of a resistance chopper device 5 shown in FIG. The difference from FIG. 11 is that the output of the current correction value circuit 30 is newly added to the adder 27 via the changeover switch 31. The changeover switch 31 is turned on and off by the output signal of the flip-flop (FF) circuit 60 in FIG.

FIG. 2 is a block diagram showing a schematic configuration of the control device of the resistance chopper device shown in FIG.
What is different from the first embodiment is that the current setting circuits 401 and 411, the adders 471 and 481, the level detection circuit (LD) 421 and
431, AND circuit (logical product circuit) 441, 451, 4
52, flip-flop (FF) circuits 60, 61, 6
2 is added.

Hereinafter, this will be described in detail. The current setting circuit (11) 401 outputs a set value signal of 13% of a predetermined current set value (second current set value), and detects the set value signal and the output current of the forward converter 3 of FIG. The detection signal of the current detector 11 is added by the adder 471. The level detection circuit (LD) 421 outputs a signal when the current value added by the adder 471 becomes equal to the second current set value.

The level detection circuit 421 becomes a first input signal of an AND circuit (logical product circuit) 441 and outputs a delay circuit (T.D) 6 when a signal is continuous for a set time period.
Enter 3 as well. The output of the delay circuit 63 is
41 becomes the second input signal and the third input signal of the AND circuit 441
As the input signal, the inverter converter operating state signal is input.

The output of the AND circuit 441 is input as a reset signal of the flip-flop (FF) circuit 60 and a set signal of the flip-flop (FF) circuit 61.

The output signal of the AND circuit 44 is input as a set signal of the flip-flop circuit 60.

The output signal of the AND circuit 44 is input as a reset signal of the flip-flop circuit 61.

The current setting circuit (21) 411 outputs a set value signal of 5.0% of a predetermined current set value (third current set value), and outputs this set value signal to the inverse converter 8 of FIG. Current detector 13 for detecting input current (inverter converter current)
Are added by the adder 481.

The level detection circuit 431 outputs a signal when the addition signal added by the adder 481 becomes equal to the third current set value. The output of the level detection circuit 431 becomes the first input signal of the AND circuit 451, and is also input to the delay (TD) circuit 64 that outputs when the signal is continuous during the set time period. The output of the delay circuit 64 becomes the second input signal of the AND circuit 451, and the third input signal of the AND circuit 451 becomes "1" in the inverter converter operating state and is input to the inverted input terminal.

The output of the AND circuit 451 receives the set signal of the flip-flop (FF) circuit 62, and the reset signal of the flip-flop (FF) circuit 62 receives the output signal of the AND circuit 45.

The output signal of the flip-flop circuit 61 is introduced into an operation / stop operation circuit (not shown) of the resistance chopper device 5 to operate and stop the resistance chopper device 5.

The output signal of the flip-flop circuit 62 is introduced into an operation / stop operation circuit (not shown) of the forward converter 3 shown in FIG. 5 so that the operation and stop of the forward converter 3 are operated. I have.

Regarding the operation of the resistance chopper device configured as described above, when the inverting device 8 is in power running operation,
The operation when the reverse conversion device 8 is performing the regenerative operation will be described.

When the inverting device 8 is running in a power running state and the vehicle starts running and the output current of the forward converting device 3 is around 10%, the adder 47 shown in FIG. When the output current of the forward converter 3 is input and becomes 10% or more of the set value of the current setting circuit (1) 40,
"1" is output from the level detection circuit 42, the condition of the AND circuit 44 is satisfied, and the flip-flop (FF) circuit 6
From 0, the changeover switch 31 of FIG. 1 is turned on, and the current of the forward conversion device 3 is 13% of the value increased by the current correction circuit 30.
The current of the forward conversion device is input to the adder 471 shown in FIG. 2, and when the current becomes 13% or more of the set value of the current setting circuit (11) 401, the level detection circuit 421 outputs Further, after a time limit set by the delay circuit (TD) 63, the condition of the AND circuit 441 is satisfied and a stop signal of the resistance chopper device is output from the flip-flop (FF) circuit 61, and the changeover switch 31 of FIG. Is released.

When the vehicle approaches the destination and the speed decreases, the current of the forward conversion device 3 becomes about 10%, and the level detection circuit 42
Is output, the condition of the AND circuit 44 is satisfied, and the flip-flop (FF) circuit 60 outputs the changeover switch 31 of FIG.
Is input, an operation signal of the resistance chopper device 5 is output from the flip-flop (FF) circuit 61, the resistance chopper device 5 is shifted to an operation state, and the current of the forward converter 3 is controlled.

On the other hand, an inverse converter (inverter converter)
FIG. 2 illustrates a case where the reference numeral 8 indicates a regenerative operation state. Immediately after the vehicle brake is applied and the regenerative operation is started, the forward conversion device 3 is operated, and the current of the inverse conversion device 8 is input to the adder 481, and the fourth current setting value of the current setting circuit (21) 411 is input. Of the level detection circuit 431
Further, after the time limit set by the delay circuit (TD) 64, the condition of the AND circuit 451 is satisfied, and the stop signal of the forward converter 3 is output from the flip-flop (FF) circuit 62, and the resistance is output. The chopper device 5 controls the DC voltage control value according to a constant voltage characteristic that is several percent higher than the DC voltage control reference value (for example, 103%) of the forward converter 3 as a DC voltage control reference value, and the resistance chopper device 5 controls the DC voltage. The regenerative current is flowing through the resistor 6 and the increase or decrease of the regenerative current is absorbed by the resistance chopper device 5, and when the regenerative current decreases, the current of the inverter converter is input to the adder 48 and the current is input. Setting circuit (2) 41: the third current set value of 1.5
%, The level detection circuit 431 outputs, the condition of the AND circuit 452 is satisfied, and the operation signal of the forward conversion device 3 is output from the flip-flop (FF) circuit 62, and the forward conversion device 3 Be driven.

According to the embodiment of the present invention, when the inverter (inverter converter) 8 is in power running operation with low power,
By adding a correction value to the current reference value of the resistance chopper device 5, even when the resistance chopper device 5 is stopped, the forward converter 3
In FIG. 3, the intermittent DC current and unnecessary operation and stop of the resistance chopper device are not repeated as shown in FIG.

Inverter (inverter converter) 8
When the regenerative operation is performed with small power, the forward conversion device 3 is operated in advance even when the regenerative power amount is lower than the power consumed at the minimum conduction angle of the resistance chopper device 5, so that as shown in FIG. Unnecessary operation and stop of the forward conversion device 3 are not repeatedly performed.

In the above-described embodiment, the input current of the reverse converter 8 is detected, and the forward converter 3 is operated and stopped. However, the current of the resistance chopper device 5 is detected, and the forward converter 3 is detected. Can be realized by driving and stopping.

In the above-described embodiment, when the reverse converter 8 is in power running operation, the output current of the forward converter 3 is detected by the current detector 11, and the reverse converter 8 is in regenerative operation. At this time, the input current of the inverting device 8 is detected by the current detector 13, but instead, it may be calculated by the following calculating means (not shown) and the calculated value may be used. That is, when the inverse converter 8 is in power running operation, the calculating means determines that the output current value of the forward converter 3 (current value detected by the current detector 11) is the input current value (current value) of the resistance chopper device 5. The calculation is performed so that the sum of the current value detected by the detector 12) and the input current value (the current value detected by the current detector 13) of the inverting device 8 becomes equal, or the calculating means is operated by the inverting device 8 During the regenerative operation, the input current value of the resistance chopper device 5 may be calculated so that the sum of the output current value of the forward conversion device 3 and the input current value of the inverse conversion device 8 becomes equal.

[0054]

According to the present invention, it is possible to provide a power conversion device having the following effects.

(1) DC power is interrupted in the forward converter, and unnecessary operation and stoppage of the resistance chopper device is performed even when the resistance chopper device is stopped during the power running operation with the power conversion current of the reverse converter being about 10%. Is not repeated.

(2) When the inverter is in regenerative operation,
Unnecessary operation of the forward converter even when the amount of regenerative power is lower than the power consumed at the minimum conduction angle of the resistance chopper device,
Stop is not repeated.

(3) DC power interruption and unnecessary operation and stop of the resistance chopper device in the forward conversion device even when the resistance chopper device is stopped during power running operation with the power conversion current of the reverse converter being about 10%. And the unnecessary operation of the forward converter even when the regenerative power is lower than the power consumed at the minimum conduction angle of the resistance chopper device when the inverter is in regenerative operation. Is not repeated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a resistance chopper device of a main part of a power converter according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a control device of the resistance chopper device of FIG. 1;

FIG. 3 is a control characteristic diagram of the inverter converter in the power converter of FIG. 1 during a power running operation.

FIG. 4 is a control characteristic diagram during a regenerative operation of the inverter converter in the power converter of FIG. 1;

FIG. 5 is a block diagram showing a schematic configuration of a conventional power converter that is also an object of the present invention.

FIG. 6 is a control characteristic diagram of the forward conversion device of FIG. 5;

7 is a control characteristic diagram of the resistance chopper device of FIG.

FIG. 8 is a control characteristic diagram of the inverter converter of FIG. 5;

FIG. 9 is a control characteristic diagram during a power running operation of the inverter converter in the conventional power converter.

FIG. 10 is a control characteristic diagram during a regenerative operation of an inverter converter in a conventional power converter.

FIG. 11 is a block diagram showing a schematic configuration of the conventional resistance chopper device of FIG. 5;

FIG. 12 is a block diagram illustrating a schematic configuration of a control device of the conventional resistance chopper device of FIG. 5;

[Description of Signs] 1 ... AC power system, 2 ... Transformer for forward converter, 3 ... Forward conversion device, 4 ... DC reactor, 5 ... Resistance chopper device, 6
... resistor, 7 ... power capacitor, 8 ... inverter converter (reverse converter), 9 ... transformer for inverter converter, 1
0 ... Load system, 11, 12, 13 ... Current detector, 14 ...
DC voltage detector, 20 DC voltage reference circuit, 21 current reference circuit, 22 constant voltage control circuit, 23 constant current control circuit, 24 limiter circuit, 25 control signal selection circuit, 2
6, 27 ... adder, 30 ... current correction circuit, 47, 48,
471, 481 adder, 31 switch, 40
Current setting circuits (1), 41 ... current setting circuits (2), 401 ...
Current setting circuits (11), 411 ... current setting circuits (21), 42 ...
Level detection circuits (1), 43 ... Level detection circuits (2), 42
1 ... Level detection circuit (11), 431 ... Level detection circuit (2
1), 44, 45: AND circuit, 46: NOT circuit, 44
1,451 ... AND circuit, 60, 61, 62 ... flip-flop (FF) circuit, 63, 64 ... delay circuit (T.
D circuit).

Claims (3)

(57) [Claims] 1. A forward conversion device for converting AC power into DC power, a resistance chopper device for consuming DC power on a DC output side through a resistor connected via a semiconductor switch, and a reverse chopper connected to a DC system. Control means for controlling the forward conversion device with a constant voltage characteristic in a power conversion device comprising: a reverse conversion device for supplying AC power obtained by a conversion operation.
And a control means for controlling the inverse conversion device by a forward conversion operation characteristic.
Stage and control for controlling the resistance chopper device by constant current characteristics
Means and, when said inverters are running operation, by detecting the output current of the forward converter, the resistor chopper set in advance
A first current detection means for detecting that the current has become equal to or greater than a first current set value corresponding to a current reference value for current control of the power device; and a detection signal from the first current detection means being input. and current correcting means for correcting the current reference value added current correction value to the current reference value of the current control of the resistor chopper device detects the output current of the forward converter, corrected by the current correcting means the Current control of resistance chopper device
A second current detection means for detecting that the current value has become equal to or greater than a second current set value corresponding to the current reference value; and a detection signal from the second current detection means is inputted. Means for stopping and canceling the correction by the current correcting means. 2. A forward conversion device for converting AC power into DC power, a resistance chopper device for consuming DC power on a DC output side through a resistor connected via a semiconductor switch, and a reverse chopper connected to a DC system. Control means for controlling the forward conversion device with a constant voltage characteristic in a power conversion device comprising: a reverse conversion device for supplying AC power obtained by a conversion operation.
And a control means for controlling the inverse conversion device by an inverse conversion operation characteristic.
And control for controlling the resistance chopper device by a constant voltage characteristic
Means for detecting, when the inverter is in regenerative operation, an input current of the inverter, and detecting that the input current is equal to or higher than a third current set value set in advance. Means, when the detection signal from the third current detection means is input, stops the forward conversion device, and sets the resistance chopper device to
A voltage higher than a voltage reference value of the voltage control of the forward conversion device
First operating means for performing voltage control based on a reference value, and detecting an input current of the inverting device to detect that the current has become equal to or less than a fourth current set value smaller than a preset third current set value. Power conversion means, comprising: a fourth current detection means for performing the operation; and a second operation means for operating the forward conversion device when a detection signal is input from the fourth current detection means. apparatus. 3. A forward converter for converting AC power into DC power, a resistance chopper device for consuming DC power on a DC output side thereof through a resistor connected via a semiconductor switch, and a reverse converter connected to a DC system. Control means for controlling the forward conversion device with a constant voltage characteristic in a power conversion device comprising: a reverse conversion device for supplying AC power obtained by a conversion operation.
And a control means for controlling the inverse conversion device by a forward conversion operation characteristic.
And a control means for controlling the inverse conversion device by an inverse operation characteristic.
Stage and control for controlling the resistance chopper device by constant current characteristics
Means and control for controlling the resistance chopper device by a constant voltage characteristic
Means and, when said inverters are running operation, by detecting the output current of the forward converter, the resistor chopper set in advance
A first current detection means for detecting that the current has become equal to or greater than a first current set value corresponding to a current reference value for current control of the power device; and a detection signal from the first current detection means being input. and current correcting means for correcting the current reference value added current correction value to the current reference value of the current control of the resistor chopper device detects the output current of the forward converter, corrected by the current correcting means the Current control of resistance chopper device
A second current detection means for detecting that the current value has become equal to or greater than a second current set value corresponding to the current reference value; and a detection signal from the second current detection means is inputted. Means for stopping and canceling the correction by the current correcting means, and when the inverter is in regenerative operation, detects an input current of the inverter and is equal to or greater than a preset third current set value A third current detecting means for detecting that the current has become zero, and when a detection signal is inputted from the third current detecting means, the forward conversion device is stopped and the resistance chopper device is turned off.
A voltage higher than a voltage reference value of the voltage control of the forward conversion device
First operating means for performing voltage control based on a reference value, and detecting an input current of the inverting device to detect that the current has become equal to or less than a fourth current set value smaller than a preset third current set value. Power conversion means, comprising: a fourth current detection means for performing the operation; and a second operation means for operating the forward conversion device when a detection signal is input from the fourth current detection means. apparatus.