JPH11113261A - Converter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a converter device which can be protected from low-level voltage hunting, by detecting the voltage hunting regardless of the frequency of the voltage hunting when the voltage hunting occurs. SOLUTION: A converter device is provided with a converter section 10 which supplies DC power obtained by converting AC power, a voltage controller 12a which amplifies and outputs the difference between the reference value of the DC voltage of the DC power and the value of the DC voltage detected by means of a DC voltage detector 8, a current controller 14 which amplifies the difference between the value of the input current to the converter section 10 detected by means of a current detector 7 and the output value of the voltage controller 12a and gives the amplified difference to the converter section 10, an oscillation discriminating voltage setter 19 which sets the voltage used for discriminating the oscillation of the detected DC voltage, a first comparator which compares the detected value of the DC voltage with its set value and outputs the voltage corresponding to the difference between the detected voltage and the set value, and gain discriminating sections which reduce the proportional gain of the voltage controller 12a based on the output voltage of the first comparator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to protection of a converter device for converting DC power from AC power and supplying the same.

[0002]

2. Description of the Related Art FIG. 11 is a block diagram showing a configuration example of a conventional converter device. This converter device 2
Three-phase AC power is supplied from the commercial AC power supply 1 to a main circuit bridge 9 made of a semiconductor, and the main circuit bridge 9 rectifies the supplied three-phase AC power into DC power and outputs the DC power. The DC power output from the main circuit bridge 9 is provided to inverters 3, 4, and 5 each having a smoothing capacitor 18. Of the three-phase input lines of the main circuit bridge 9, two-phase input lines have a CT 6 (Current Transf.) For detecting an alternating current.
ormer) is attached, and the outputs of these two CTs 6 are supplied to a current detector 7 to detect an input current to the main circuit bridge 9.

A DC voltage detection circuit 8 is connected between output lines of the main circuit bridge 9 and detects a DC voltage output from the converter device 2. The main circuit bridge 9, the CT 6, and the DC voltage detection circuit 8 constitute a converter main circuit 10. The DC voltage value detected by the DC voltage detection circuit 8 is supplied to the voltage controller 12 and the overvoltage detection circuit 13, and the voltage controller 12 supplies the DC voltage value and a reference value of the DC voltage output from the converter device 2. A deviation from the reference DC voltage value from the reference circuit 11 is amplified and output. The overvoltage detection circuit 13 supplies a signal for stopping to the interlock circuit 16 when the DC voltage value from the DC voltage detection circuit 8 reaches a preset overvoltage.

The current value detected by the current detector 7 is supplied to a current controller 14 and an overcurrent detection circuit 15, and the current controller 14 amplifies a deviation between the current value and the output of the voltage controller 12, and The control signal is given to the main circuit bridge 9. The overcurrent detection circuit 15 outputs a stop signal to the interlock circuit 16 when the current value from the current detector 7 reaches a preset current value.
Give to. The interlock circuit 16 stops the main circuit bridge 9 and stops the converter main circuit 10 when a stop signal is given from the overvoltage detection circuit 13 or the overcurrent detection circuit 15.

[0005] The operation of the converter device 2 having such a configuration will be described below. The converter device 2 supplies DC power to the voltage-type inverters 3 to 5 including the capacitor load 18, and controls the DC voltage to be constant with respect to the load fluctuation. That is, the output voltage is
Is controlled by the voltage controller 12 so that the reference DC voltage value is output.

When the load includes the capacitor 18, for example, if the load of the inverter 3 increases and a large amount of current flows, the charge of the capacitor 18 decreases, and the DC voltage instantaneously decreases. Since the voltage controller 12 amplifies the deviation between the detection value of the DC voltage detection circuit 8 and the reference DC voltage value to generate a current instruction signal, when the load of the inverter 3 increases rapidly, the detection value of the DC voltage detection circuit 8 increases. And the reference DC voltage value increases, and the reference current value output to the current controller 14 increases. Therefore, the current instruction value given by the current controller 14 to the main circuit bridge 9 increases,
The main circuit bridge 9 operates to supply a large amount of current to the capacitor 18 so as to reduce the fluctuation of the DC voltage detected by the DC voltage detection circuit 8.

[0007] The amplification factor of the voltage controller 12 is calculated based on the capacity of the capacitor 18 or the like serving as a load, and is set so that the DC voltage control system is stabilized. For example, when the amplification factor is high, overshoot and undershoot are repeated. In that case, when the change amount reaches the voltage value set in the overvoltage detection circuit 13,
A signal for stopping is supplied from the overvoltage detection circuit 13 to the interlock circuit 16, and the interlock circuit 16 stops the main circuit bridge 9 and stops the converter main circuit 10 to protect the components.

However, when hunting, which is a repetition of overshoot and undershoot, does not reach the voltage value set in the overvoltage detection circuit 13,
If the interlock circuit 16 does not operate and the hunting continues, the temperature of the capacitor 18 as a load may be increased due to the ripple current and may be damaged. The overcurrent detection circuit 15 supplies a stop signal to the interlock circuit 16 when the current value from the current detector 7 reaches a preset current value, and the interlock circuit 16 The circuit bridge 9 is stopped and the converter main circuit 10 is stopped to protect the components.

[0009]

As described above, in the conventional converter device 2, when an overvoltage equal to or higher than the overvoltage set value occurs even once, the interlock circuit 16 is activated and stopped. In the case where the voltage fluctuation occurs due to the normal load fluctuation of FIG. 5, if the overvoltage set value is set low, the operation stops. On the contrary, if the overvoltage set value is set high, the interlock circuit 16 is stopped.
There is a problem that the hunting in a voltage range in which the capacitor does not operate may cause the damage of the capacitor 18.

Japanese Patent Laid-Open Publication No. Hei 6-284732 discloses a technique for preventing voltage fluctuation of DC power, which detects a voltage change of a smoothing capacitor due to a change in load and obtains a rate of the change to prevent the control characteristics from becoming unstable. A "voltage power supply device" is disclosed in which the change rate value is adjusted by a voltage change rate value gain adjuster to be a part of a feedback amount to a current control arithmetic unit, thereby suppressing a change in output voltage. . The present invention has been made in view of the above-described circumstances, and when low-level voltage hunting occurs, detects and suppresses the voltage hunting regardless of the frequency to protect the hunting from voltage hunting. It is an object of the present invention to provide a converter device capable of performing the following.

[0011]

According to a first aspect of the present invention, there is provided a converter unit for supplying DC power converted from AC power, a DC voltage detection circuit for detecting a DC voltage output from the converter unit, A reference circuit that outputs a reference value of a DC voltage; a voltage controller that amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit; and an input to the converter unit. A current detector that detects a current, a current controller that amplifies a deviation between the current value detected by the current detector and an output value of the voltage controller, and provides the current control signal to the converter unit; and the DC voltage detection circuit includes: When the detected voltage vibrates, a vibration determination voltage setting device that sets a voltage for determining the vibration, and a voltage detected by the DC voltage detection circuit. A first comparator that compares a voltage set by the vibration determination voltage setter with a voltage set by the detected voltage and outputs a voltage corresponding to the amount exceeding the set voltage, and a voltage output by the first comparator. A gain determining unit that determines whether to reduce the proportional gain of the voltage controller based on the gain, and outputs a signal that reduces the proportional gain by a predetermined value when it is determined that the proportional gain should be reduced. I do.

[0012] In the converter device according to the second aspect of the invention, the gain judging section should reduce an integrator for integrating the voltage output from the first comparator and a proportional gain of the voltage controller for the voltage output from the integrator. A level setting device for setting a level, comparing the level set by the level setting device with the voltage output by the integrator, and when the voltage reaches the level, reduces the proportional gain by a predetermined value. A second comparator for outputting a signal and resetting the integrator.

[0013] In the converter device according to a third aspect of the present invention, the gain judging section comprises: a waveform shaping circuit for shaping the output of the first comparator into a rectangular wave; a counter for counting the square wave output from the waveform shaping circuit; A judgment value setting device for setting a judgment value of the count value of the counter to reduce the proportional gain of the voltage controller; comparing the judgment value set by the judgment value setting device with the count value of the counter; And a third comparator for outputting a signal for reducing the proportional gain by a predetermined value when the value reaches the determination value, and for resetting the counter.

According to a fourth aspect of the present invention, there is provided a converter device including a reset circuit for resetting a counter when a rectangular wave output from the waveform shaping circuit is not input for a predetermined time.

According to a fifth aspect of the present invention, the gain determination section has a waveform shaping circuit for shaping the output of the first comparator into a rectangular wave, and a clock generator, and the rectangular wave output from the waveform shaping circuit. An up / down counter for counting down the clock generated by the clock generator, a determination value setting device for setting a determination value of the count value of the up / down counter to reduce the proportional gain of the voltage controller, A fourth comparing step of comparing a judgment value set by the value setting device with a count value of the up / down counter and outputting a signal for reducing the proportional gain by a predetermined value when the count value reaches the judgment value; And the up-down counter when the fourth comparator outputs the signal and when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time. Characterized in that it comprises a reset circuit for starting the countdown.

According to a sixth aspect of the present invention, there is provided a converter unit for supplying DC power converted from AC power, a DC voltage detection circuit for detecting a DC voltage output from the converter unit, and a reference value for the DC voltage. A reference circuit to output,
A voltage controller that amplifies and outputs a difference between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit; a current detector that detects an input current to the converter unit; Amplifies the deviation between the current value detected by the detector and the output value of the voltage controller, and provides a current controller to the converter unit as a current control signal, and when the voltage detected by the DC voltage detection circuit vibrates, A vibration determination voltage setting device for setting a voltage for determination, a voltage detected by the DC voltage detection circuit is compared with a voltage set by the vibration determination voltage setting device, and the detected voltage is the set voltage. A deviation amplifier that amplifies the difference between the two voltages when the difference is exceeded and outputs it as a rectangular wave voltage; and a voltage controller based on the square wave voltage output by the deviation amplifier. Determining whether to reduce the proportional gain, when it is determined that should be reduced, characterized in that it comprises a gain determination unit that outputs a signal to the proportional gain is reduced a predetermined value min.

In the converter device according to a seventh aspect of the present invention, the gain determining section should reduce an integrator for integrating the rectangular wave voltage output from the deviation amplifier and a proportional gain of the voltage controller for the voltage output from the integrator. A level setting device for setting a level, comparing the level set by the level setting device with the voltage output by the integrator, and when the voltage reaches the level, reduces the proportional gain by a predetermined value. A fifth comparator for outputting a signal and resetting the integrator.

In the converter device according to an eighth aspect of the present invention, the gain determining section includes a counter for counting the rectangular wave voltage output from the deviation amplifier, and a determination value for reducing the proportional gain of the voltage controller, based on the count value of the counter. A judgment value setting device to be set, and a judgment value set by the judgment value setting device is compared with a count value of the counter. When the count value reaches the judgment value, the proportional gain is reduced by a predetermined value. And a reset circuit that resets the counter when the sixth comparator outputs the signal and when the square wave voltage output from the deviation amplifier is not input for a predetermined time. It is characterized by the following.

[0019] In the converter device according to the ninth aspect, the gain judging section counts the rectangular wave voltage output from the deviation amplifier,
An up / down counter for counting down a clock generated by the clock generator; and a determination value for setting a determination value of the count value of the up / down counter to reduce a proportional gain of the voltage controller. A setting device, for comparing a judgment value set by the judgment value setting device with a count value of the up / down counter, and when the count value reaches the judgment value, a signal for reducing the proportional gain by a predetermined value. And the up / down counter starts counting down the clock when the seventh comparator outputs the signal and when the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time. And a reset circuit.

A converter unit according to a tenth aspect of the present invention includes a converter unit for supplying DC power converted from AC power,
A DC voltage detection circuit for detecting a DC voltage output by the converter unit, a reference circuit for outputting a reference value of the DC voltage, a reference value output by the reference circuit, and a DC voltage value detected by the DC voltage detection circuit A voltage controller that amplifies and outputs the deviation of the current, a current detector that detects an input current to the converter unit, and a current value detected by the current detector and a deviation between the output value of the voltage controller and the current controller. A current controller to be provided to the converter section as a control signal, a vibration determination voltage setting device for setting a voltage for determining the vibration when the voltage detected by the DC voltage detection circuit vibrates, and the DC voltage detection circuit Compares the detected voltage with the voltage set by the vibration determination voltage setting device, and outputs an ON signal when the detected voltage exceeds the set voltage. An eighth comparator, a relay that is turned on by an on signal output from the eighth comparator, a signal generator that generates a predetermined voltage signal when the relay is on, and a signal generator that generates the predetermined voltage signal. A gain determining unit that determines whether to reduce the proportional gain of the voltage controller based on the voltage signal that has been made, and, when it is determined that the proportional gain should be reduced, outputs a signal that reduces the proportional gain by a predetermined value. It is characterized by having.

[0021] In the converter device according to the eleventh aspect, the gain judging unit should reduce the proportional gain of the voltage controller of the voltage output by the integrator and the voltage output by the signal generator. A level setting device for setting a level, comparing the level set by the level setting device with the voltage output by the integrator, and when the voltage reaches the level, reduces the proportional gain by a predetermined value. A ninth comparator that outputs a signal and resets the integrator.

In the converter device according to the twelfth aspect, the gain determining section includes a counter for counting the voltage signal output from the signal generator, and a determination value for reducing the proportional gain of the voltage controller, based on the count value of the counter. A judgment value setting device to be set, a comparison between the judgment value set by the judgment value setting device and the count value of the counter, and when the count value reaches the judgment value, a signal for reducing the proportional gain. Output,
In addition, a tenth comparator for resetting the counter is provided.

[0023] In the converter device according to the thirteenth aspect, the gain judging section counts the voltage signal output by the signal generator,
And an up / down counter for counting down the clock generated by the clock generator, and a determination value for setting a determination value of the count value of the up / down counter to reduce the proportional gain of the voltage controller. A setting device, which compares a judgment value set by the judgment value setting device with a count value of the up / down counter, and outputs a signal for reducing the proportional gain when the count value reaches the judgment value. An eleventh comparator, and a reset circuit for causing the up / down counter to start counting down the clock when the eleventh comparator outputs the signal and when the voltage signal output from the signal generator is not input for a predetermined time. It is characterized by having.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention. The converter device 27 includes a main circuit bridge 9 made of a semiconductor, which rectifies three-phase AC power supplied from the commercial AC power supply 1 to DC power and outputs the DC power. The DC power output from the main circuit bridge 9 is smoothed. It is provided to inverters 3, 4, and 5 each having a capacitor 18. 3 of main circuit bridge 9
Of the phase input lines, two-phase input lines are provided with CT6 (Current Transformer) for detecting an AC current, respectively, and the outputs of the two CT6 are supplied to a current detector 7 and a main circuit bridge 9 is provided. The input current to is detected.

The converter device 27 further includes a DC voltage detection circuit 8 connected between the output lines of the main circuit bridge 9 and detecting the DC voltage output from the converter device 27.
The main circuit bridge 9, the CT 6, and the DC voltage detection circuit 8
The converter main circuit 10 is constituted.

The converter device 27 is also supplied with the DC voltage value detected by the DC voltage detection circuit 8, and receives a reference DC voltage from the reference circuit 11 that provides the DC voltage value and a reference value of the DC voltage output from the converter device 27. A voltage controller 12a for amplifying and outputting a deviation from the voltage value and a current value detected by the current detector 7 are provided. The deviation between the current value and the output of the voltage controller 12a is amplified, and the amplified value is mainly used as a current control signal. Current controller 1 applied to circuit bridge 9
4, an interlock circuit 25 for stopping the main circuit bridge 9 (converter main circuit 10), and a current value detected by the current detector 7, and the current value reaches a preset current value. Sometimes, an overcurrent detection circuit 15 for providing a signal for stopping to the interlock circuit 25 is provided.

The converter device 27 also includes a vibration (hunting) determination voltage setting unit 19 for setting a voltage value for determining the vibration when the voltage value detected by the DC voltage detection circuit 8 vibrates (hunting). And the voltage value detected by the DC voltage detection circuit 8 and the hunting determination voltage setting device 19
The comparator 20 compares the detected voltage value with the set voltage value and outputs a voltage corresponding to the amount of the detected voltage value exceeding the set voltage value.
(First comparator).

Converter device 27 also includes a comparator 20
And a level setter 22 for setting a level of the voltage output by the integrator 21 at which the proportional gain of the voltage controller 12a should be reduced.
And the level set by the level setting unit 22 and the voltage output by the integrator 21. When the voltage reaches the level, the signal for reducing the proportional gain of the voltage controller 12a and the integrator 21 are reset. Comparator 23 (second comparator) for outputting a signal to be
And a gain correction circuit 24 for receiving a signal for reducing the proportional gain of 2a and reducing the proportional gain of the voltage controller 12a by a predetermined value.

The operation of the converter device 27 having such a configuration will be described below. The converter device 27 supplies DC power to the voltage-type inverters 3 to 5 including the capacitor load 18, and controls the DC voltage to be kept constant with respect to the load fluctuation. That is, the voltage controller 12a controls the output voltage to be the reference DC voltage value output from the reference circuit 11.

When the load includes the capacitor 18, for example, if the load of the inverter 3 increases and a large amount of current flows, the charge of the capacitor 18 decreases and the DC voltage instantaneously decreases. The voltage controller 12a amplifies the difference between the detection value of the DC voltage detection circuit 8 and the reference DC voltage value to generate a current instruction signal. Therefore, when the load of the inverter 3 increases rapidly, the detection value of the DC voltage detection circuit 8 And the reference DC voltage value increases, and the reference current value output to the current controller 14 increases. Therefore, the current instruction value given to the main circuit bridge 9 by the current controller 14 increases, and the main circuit bridge 9 supplies a large amount of current to the capacitor 18 to reduce the fluctuation of the DC voltage detected by the DC voltage detection circuit 8. It works as follows.

When the current value from the current detector 7 reaches a preset overcurrent value, the overcurrent detection circuit 15 provides a signal for stopping to the interlock circuit 25,
The interlock circuit 25 stops the main circuit bridge 9 and stops the converter main circuit 10 to protect the components.

The amplification factor of the voltage controller 12a is calculated based on the capacity of the capacitor 18 or the like serving as a load, and is set so that the DC voltage control system is stabilized. Here, when the capacitance of the capacitor 18 changes, especially when it decreases, the amplification factor becomes relatively high with respect to the capacitance of the capacitor 18, and hunting between overshoot and undershoot is repeated.

In this case, if the voltage value detected by the DC voltage detection circuit 8 continues hunting, the comparator 2
0 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and outputs a voltage corresponding to the detected voltage value exceeding the set voltage value. . The voltage output from the comparator 20 is output to the integrator 21
Is integrated and output. The voltage integrated and output by the integrator 21 is compared with the level set by the level setter 22 by the comparator 23. When the voltage reaches the level, the comparator 23 reduces the proportional gain of the voltage controller 12a. The signal is given to the gain correction circuit 24, and the signal for resetting the integrator 21 is given to the integrator 21.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The integrator 21 is reset by receiving a signal for resetting the integrator 21. Converter device 27 reduces the proportional gain of voltage controller 12a by a predetermined value.
If the voltage value detected by the DC voltage detection circuit 8 continues hunting, the above operation is repeated until the voltage integrated and output by the integrator 21 does not reach the level set by the level setting device 22. , Load capacitor 18
However, it prevents the temperature from rising due to the ripple current and causing damage.

The detection time of the hunting operation varies depending on the amount of the voltage exceeding the voltage value set by the hunting determination voltage setting device 19 and the frequency thereof. This is because the integrator 21 is used to operate when the integrated value exceeds the level set by the level setting unit 22. If the ripple is large, the detection time becomes short, If the ripple is small, the detection time will be long. The detection time also varies depending on the level of the frequency of the hunting operation.
However, the capacitor 18 can be protected by appropriately setting the set level of the level setting unit 22 according to the characteristics of the capacitor 18. As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 27 can detect and suppress the hunting to protect the component devices.

Embodiment 2 FIG. 2 is a block diagram showing the configuration of the embodiment of the converter device according to the present invention. In the converter device 34, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and the detected voltage value exceeds the set voltage value. The voltage output according to the minute,
A waveform shaping circuit 28 for shaping into a rectangular wave, and a waveform shaping circuit 2
8 is provided with a counter 29 for counting the rectangular waves output.

The converter device 34 also includes a counter 2
A judgment value setting unit 30 for setting a judgment value of the count value of 9 to reduce the proportional gain of the voltage controller 12a;
The judgment value set by the judgment value setting unit 30 is compared with the count value of the counter 29. When the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the counter 29 are generated. Output comparator 3
1 (third comparator) and a signal for reducing the proportional gain of the voltage controller 12a.
Gain correction circuit 2 for reducing the proportional gain of a by a predetermined value
4 is provided. Other configurations are the same as the configuration of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

The operation of the converter device 34 having such a configuration will be described below. In the converter device 34, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19,
A voltage corresponding to a portion where the detected voltage value exceeds the set voltage value is output. The waveform shaping circuit 28 shapes this voltage output from the comparator 20 into a rectangular wave and outputs it. Counter 29
Counts the rectangular waves output by the waveform shaping circuit 28.

The comparator 31 compares the count value of the counter 29 with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a. To the gain correction circuit 24, and a signal for resetting the counter 29 to the counter 29. The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value. The counter 29 is reset by receiving a signal for resetting the counter 29.

The converter device 34 reduces the count value of the counter 29 if the voltage value detected by the DC voltage detection circuit 8 continues hunting even if the proportional gain of the voltage controller 12a is reduced by a predetermined value. , Judgment value setting device 3
The above operation is repeated until 0 does not reach the set count value, thereby preventing the capacitor 18 of the load from being damaged due to the rise in temperature due to the ripple current. Other operations are similar to those of converter device 27 described in the first embodiment.
Since the operation is the same as that described above, the description is omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 34 can detect and suppress the hunting to protect the constituent devices. Further, since the waveform of the output voltage of the comparator 20 is shaped into a rectangular wave by the waveform shaping circuit 28 and counted by the counter 29, if the hunting frequency is the same, the detection time of the hunting operation is determined by the DC voltage detection circuit 8 Are substantially the same regardless of the detected voltage value.

Embodiment 3 FIG. 3 is a block diagram showing the configuration of the embodiment of the converter device according to the present invention. In the converter device 42, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and the detected voltage value exceeds the set voltage value. The voltage output according to the minute,
A waveform shaping circuit 35 for shaping into a rectangular wave, and a waveform shaping circuit 3
5 includes a counter 37 for counting the rectangular waves output by the counter 5 and a reset circuit 36 for resetting the counter 37 when the rectangular waves output by the waveform shaping circuit 35 are not input for a predetermined time.

The converter device 42 also includes a counter 3
A judgment value setting unit 30 for setting a judgment value of the count value of 7 to reduce the proportional gain of the voltage controller 12a;
The judgment value set by the judgment value setting device 30 is compared with the count value of the counter 37, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the counter 37 are generated. Output comparator 3
9 (third comparator) and a signal for reducing the proportional gain of the voltage controller 12a.
Gain correction circuit 2 for reducing the proportional gain of a by a predetermined value
4 is provided. Other configurations are the same as the configuration of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

The operation of the converter device 42 having such a configuration will be described below. In the converter device 42, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19,
A voltage corresponding to a portion where the detected voltage value exceeds the set voltage value is output. The waveform shaping circuit 35 shapes this voltage output from the comparator 20 into a rectangular wave and outputs it. Counter 37
Counts the rectangular waves output by the waveform shaping circuit 35. On the other hand, the reset circuit 36 resets the counter 37 when the rectangular wave output from the waveform shaping circuit 35 is not input for a predetermined time.

The comparator 39 compares the count value of the counter 37 with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a. To the gain correction circuit 24 and a signal for resetting the counter 37 to the reset circuit 36.
Give to each. The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a,
The proportional gain of the voltage controller 12a is reduced by a predetermined value. The reset circuit 36 resets the counter 37 upon receiving a signal for resetting the counter 37.

Even if the converter device 42 reduces the proportional gain of the voltage controller 12a by a predetermined value, if the voltage value detected by the DC voltage detection circuit 8 continues to hunt, the count value of the counter 37 is increased. , Judgment value setting device 3
The above operation is repeated until 0 does not reach the set count value, thereby preventing the capacitor 18 of the load from being damaged due to the rise in temperature due to the ripple current. Other operations are similar to those of converter device 27 described in the first embodiment.
Since the operation is the same as that described above, the description is omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 42 can detect and suppress the hunting to protect the constituent devices. Further, since the waveform of the output voltage of the comparator 20 is shaped into a rectangular wave by the waveform shaping circuit 35 and counted by the counter 37, if the hunting frequency is the same, the detection time of the hunting operation is determined by the DC voltage detection circuit 8 Are substantially the same irrespective of the detected voltage value, and when hunting does not continue for a certain period of time, the counter 37 is reset. Therefore, even if hunting occurs temporarily due to the behavior of the load of the inverters 3 to 5, It can be distinguished from hunting due to a change in the capacitance of the capacitor 18.

Embodiment 4 FIG. 4 is a block diagram showing the configuration of the embodiment of the converter device according to the present invention. In the converter device 48, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and the detected voltage value exceeds the set voltage value. The voltage output according to the minute,
An up / down counter having a waveform shaping circuit 35 for shaping into a rectangular wave, and a clock generator (not shown) for counting the square waves output from the waveform shaping circuit 35 and counting down the clock generated by the clock generator. 43, and a reset circuit 36 that causes the up / down counter 43 to start counting down the clock when the rectangular wave output from the waveform shaping circuit 35 is not input for a predetermined time.

The converter device 48 also includes a judgment value setting device 30 for setting a judgment value of the count value of the up / down counter 43 to reduce the proportional gain of the voltage controller 12a, and a judgment value set by the judgment value setting device 30. The comparator compares the value with the count value of the up / down counter 43, and outputs a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the up / down counter 43 when the count value reaches the determination value. 45 (fourth comparator) and a gain correction circuit 24 that receives a signal for reducing the proportional gain of the voltage controller 12a and reduces the proportional gain of the voltage controller 12a by a predetermined value.

The reset circuit 36 receives the signal for resetting the up / down counter 43 and causes the up / down counter 43 to start counting down the clock.
Other configurations are the same as the configuration of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

The operation of the converter device 48 having such a configuration will be described below. In the converter device 48, the comparator 20 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19,
A voltage corresponding to a portion where the detected voltage value exceeds the set voltage value is output. The waveform shaping circuit 35 shapes the voltage output from the comparator 20 into a rectangular wave and outputs the rectangular wave, and the up / down counter 43 counts the rectangular waves output from the waveform shaping circuit 35.

On the other hand, when the rectangular wave output from the waveform shaping circuit 35 is not input for a predetermined time, the reset circuit 36
The up / down counter 43 starts counting down the clock. The up / down counter 43 terminates the countdown when counting down to 0, and stops counting down when a rectangular wave is input from the waveform shaping circuit 35 while counting down, and stops counting at that time. Starts counting from.

The comparator 45 has an up / down counter 43
Is compared with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a is sent to the gain correction circuit 24, and the up-down counter A signal for resetting 43 is output to the reset circuit 36.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The reset circuit 36 receives the signal for resetting the up / down counter 43 and causes the up / down counter 43 to start counting down the clock. Other operations are similar to those of converter device 27 described in the first embodiment.
Since the operation is the same as that described above, the description is omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 48 can detect and suppress the hunting to protect the constituent devices. Since the waveform of the output voltage of the comparator 20 is shaped into a rectangular wave by the waveform shaping circuit 35 and counted by the up / down counter 43, if the hunting frequency is the same, the detection time of the hunting operation is:
They are substantially the same regardless of the voltage value detected by the DC voltage detection circuit 8.

When hunting does not continue for a certain period of time, the up / down counter 43 starts counting down the clock. It can be distinguished from hunting due to fluctuation, and if a rectangular wave is input before the countdown ends, the countdown is stopped and counting is started from the count value at that time. Even if hunting occurs repeatedly in a short time due to the behavior of the load, it can be distinguished from hunting due to a change in the capacitance of the capacitor 18.

Embodiment 5 FIG. 5 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention. The converter device 55 includes a hunting determination voltage setting device 19 that sets a voltage value for determining hunting when the DC voltage value detected by the DC voltage detection circuit 8 hunts, and the DC voltage detection circuit 8 detects the hunting. The detected voltage value is compared with the voltage value set by the hunting determination voltage setting device 19, and when the detected voltage value exceeds the set voltage value, the deviation between the two voltage values is amplified and output as a rectangular wave voltage. An amplifier 49 is provided.

The converter device 55 also sets an integrator 50 for integrating the rectangular wave voltage output from the deviation amplifier 49 and a level at which the proportional gain of the voltage controller 12a of the voltage output from the integrator 50 is reduced. The level setter 22 compares the level set by the level setter 22 with the voltage output by the integrator 50, and when the voltage reaches the level, a signal for reducing the proportional gain of the voltage controller 12a and an integration. A comparator 52 (fifth comparator) for outputting a signal for resetting the unit 50, and a gain correction circuit for receiving a signal for reducing the proportional gain of the voltage controller 12a and reducing the proportional gain of the voltage controller 12a by a predetermined value. 24. Other configurations are the same as the configuration of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

The operation of the converter device 55 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 continues hunting, the deviation amplifier 49 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19. And
When the detected voltage value exceeds the set voltage value, the difference between the two voltage values is amplified and output as a rectangular wave.

The square wave voltage output from the deviation amplifier 49 is
It is integrated by the integrator 50 and output. The voltage output from the integrator 50 is compared with the level set by the level setter 22 by the comparator 52. When the voltage reaches the level, the comparator 52 outputs a signal for reducing the proportional gain of the voltage controller 12a. The gain correction circuit 24 includes an integrator 5
A signal for resetting 0 is output to the integrator 50, respectively.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
Other operations are the same as the operations of converter device 27 described in the first embodiment, and a description thereof will not be repeated. As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 55 can detect and suppress the hunting to protect the constituent devices.

Embodiment 6 FIG. FIG. 6 is a block diagram showing the configuration of the embodiment of the converter device according to the present invention. The converter device 63 includes a counter 58 for counting the rectangular wave voltage output from the deviation amplifier 56, and a counter 5
A judgment value setting unit 30 for setting a judgment value of the count value of 8 to reduce the proportional gain of the voltage controller 12a;
The judgment value set by the judgment value setting unit 30 is compared with the count value of the counter 58. When the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the counter 58 are generated. And a comparator 60 (sixth comparator) for outputting the respective signals.

The converter device 63 receives the signal for reducing the proportional gain of the voltage controller 12a, and receives the signal for resetting the counter 58 and the gain correction circuit 24 for reducing the proportional gain of the voltage controller 12a by a predetermined value. And a reset circuit 57 for resetting the counter 58 when receiving the rectangular wave voltage output from the deviation amplifier 56 for a predetermined time.
Other configurations are the same as those of converter device 55 described in the fifth embodiment, and a description thereof will not be repeated.

Hereinafter, the operation of the converter device 63 having such a configuration will be described. The converter device 63 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19 when the deviation amplifier 56 determines that the detected voltage value exceeds the set voltage value. Is
The difference between the two voltage values is amplified and output as a rectangular wave.
The counter 58 counts the rectangular wave voltage output by the deviation amplifier 56. On the other hand, the reset circuit 57
When the rectangular wave output from 6 is not input for a predetermined time, the counter 58 is reset.

The comparator 60 compares the count value of the counter 58 with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a. To the gain correction circuit 24 and a signal for resetting the counter 58 to the reset circuit 57.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The reset circuit 57 resets the counter 58 upon receiving a signal for resetting the counter 58. Other operations are the same as those of converter device 55 described in the fifth embodiment, and a description thereof will not be repeated.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 63 can detect and suppress the hunting to protect the components. Further, since the deviation amplifier 56 shapes the output voltage into a rectangular wave and counts it by the counter 58, if the hunting frequency is the same, the detection time of the hunting operation is related to the voltage value detected by the DC voltage detection circuit 8. When the hunting does not continue for a certain period of time, the counter 58 is reset. Therefore, even if the hunting occurs temporarily due to the behavior of the load of the inverters 3 to 5, the hunting due to the variation in the capacitance of the capacitor 18 occurs. Can be distinguished.

Embodiment 7 FIG. 7 is a block diagram showing a configuration of a converter device according to an embodiment of the present invention. The converter device 70 has an up / down counter 6
5 is provided. The up / down counter 65 counts the square wave voltage output from the deviation amplifier 56, has a clock generator (not shown), and counts down the clock generated by the clock generator.

The converter device 70 also includes a judgment value setting unit 30 for setting a judgment value of the count value of the up / down counter 65 to reduce the proportional gain of the voltage controller 12a, and a judgment value set by the judgment value setting unit 30. The comparator 67 compares the value with the count value of the up / down counter 65, and outputs a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the counter 58 when the count value reaches the determination value. A seventh comparator).

The converter device 70 receives the signal for reducing the proportional gain of the voltage controller 12a, and resets the gain correction circuit 24 for reducing the proportional gain of the voltage controller 12a by a predetermined value and the up / down counter 65. A reset circuit 64 is provided which causes the up / down counter 65 to start counting down the clock when receiving the signal and when the rectangular wave voltage output from the deviation amplifier 56 is not input for a predetermined time. Other configurations are the same as those of converter device 55 described in the fifth embodiment, and a description thereof will not be repeated.

The operation of converter device 70 having such a configuration will be described below. The converter device 70 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19 when the deviation amplifier 56 determines that the detected voltage value exceeds the set voltage value. Is
The difference between the two voltage values is amplified and output as a rectangular wave.
The up / down counter 65 counts the rectangular waves output by the deviation amplifier 56.

On the other hand, the reset circuit 64
When the rectangular wave output from 6 is not input for a predetermined time, the up / down counter 65 starts counting down the clock. The up / down counter 65 ends the countdown when counting down to 0, and stops counting down when a rectangular wave is input from the deviation amplifier 56 while counting down, and stops counting down from the count value at that time. Start counting.

The comparator 67 has an up / down counter 65
Is compared with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a is sent to the gain correction circuit 24, and the up-down counter A signal for resetting the reset signal 65 is output to the reset circuit 64.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The reset circuit 64 receives the signal for resetting the up / down counter 65 and causes the up / down counter 65 to start counting down the clock. Other operations are similar to those of converter device 55 described in the fifth embodiment.
Since the operation is the same as that described above, the description is omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 70 can detect and suppress the hunting to protect the component devices. Further, since the deviation amplifier 56 shapes the output voltage into a rectangular wave and counts it by the up / down counter 65, if the hunting frequency is the same, the detection time of the hunting operation is determined by the voltage value detected by the DC voltage detection circuit 8. Irrespective of.

When hunting does not continue for a certain period of time, the up / down counter 65 starts counting down the clock. It can be distinguished from hunting due to fluctuation, and if a rectangular wave is input before the countdown ends, the countdown is stopped and counting is started from the count value at that time. Even if hunting occurs repeatedly in a short time due to the behavior of the load, it can be distinguished from hunting due to a change in the capacitance of the capacitor 18.

Embodiment 8 FIG. FIG. 8 is a block diagram showing the configuration of the embodiment of the converter device according to the present invention. The converter device 81 includes a hunting determination voltage setting device 19 that sets a voltage for determining hunting when a voltage value detected by the DC voltage detection circuit 8 hunts, and a voltage detected by the DC voltage detection circuit 8. The comparator 71 (eighth comparator) that compares the value with the voltage value set by the hunting determination voltage setting device 19 and outputs an ON signal when the detected voltage value exceeds the set voltage value, 73 which is turned on by the ON signal output from the heater 71
(Relay contact 74) and a signal generator 72 for generating a predetermined voltage signal when the relay 73 is on. Comparator 71, relay 73 and signal generator 72
Constitutes an insulation comparator 75.

The converter device 81 also sets an integrator 76 for integrating the voltage signal output from the signal generator 72 and a level at which the proportional gain of the voltage controller 12a of the voltage output from the integrator 76 should be reduced. The level setter 22 compares the level set by the level setter 22 with the voltage output by the integrator 76, and when the voltage reaches the level, a signal for reducing the proportional gain of the voltage controller 12a and the integration. 78 (a ninth comparator) for outputting a signal for resetting the comparator 76, and a gain correction circuit for receiving a signal for reducing the proportional gain of the voltage controller 12a and reducing the proportional gain of the voltage controller 12a by a predetermined value. 24. Other configurations are the same as the configuration of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

The operation of the converter device 81 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 continues hunting, the comparator 71
Compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and outputs an ON signal when the detected voltage value exceeds the set voltage value. The relay 73 is turned on by the ON signal output from the comparator 71, and the signal generator 72 outputs a predetermined voltage signal when the relay 73 is turned on.

The voltage signal output by signal generator 72 is integrated by integrator 76 and output. The voltage output from the integrator 76 is compared by the comparator 78 with the level set by the level setter 22, and when the voltage reaches that level,
The comparator 78 outputs a signal for reducing the proportional gain of the voltage controller 12a to the gain correction circuit 24 and a signal for resetting the integrator 76 to the integrator 76.

The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The integrator 76 is reset by receiving a signal for resetting the integrator 76. Other operations are the same as the operations of converter device 27 described in the first embodiment, and a description thereof will not be repeated.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 81 can detect and suppress the hunting to protect the components. The comparator 71 and the relay 73
Further, the protection circuit after the integrator 76 and the DC voltage detection circuit 8 can be insulated by the signal generator 72, and the output voltage of the signal generator 72 is shaped into a rectangular wave by the relay 73.
6, the detection time of the hunting operation is substantially the same regardless of the voltage value detected by the DC voltage detection circuit 8 if the hunting frequency is the same.

Embodiment 9 FIG. FIG. 9 is a block diagram showing a configuration of a converter device according to an embodiment of the present invention. The converter device 87 includes a counter 82 for counting the voltage signal output from the signal generator 72, and a counter 82
The judgment value setter 30 for setting the judgment value for reducing the proportional gain of the voltage controller 12a of the count value of the voltage controller 12a is compared with the judgment value set by the judgment value setter 30 and the count value counted by the counter 82, A comparator 84 (tenth comparator) is provided which outputs a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the counter 82 when the counted value reaches the determination value.

The converter device 87 further includes a gain correction circuit 24 which receives a signal for reducing the proportional gain of the voltage controller 12a and reduces the proportional gain of the voltage controller 12a by a predetermined value. Other configurations are the same as those of converter device 81 described in the eighth embodiment, and a description thereof will not be repeated.

The operation of converter device 87 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 continues hunting, the comparator 71
Compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and outputs an ON signal when the detected voltage value exceeds the set voltage value. The relay 73 is turned on by the ON signal output from the comparator 71, and the signal generator 72 outputs a predetermined voltage signal when the relay 73 is turned on. The counter 82 counts the voltage signal that is a rectangular wave output from the signal generator 72.

The comparator 84 compares the count value of the counter 82 with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a. To the gain correction circuit 24 and a signal to reset the counter 82 to the counter 82. The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value.
The counter 82 is reset by receiving a signal for resetting the counter 82. Other operations are the same as those of converter device 80 described in the eighth embodiment, and a description thereof will not be repeated.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 87 can detect and suppress the hunting to protect the components. The comparator 71 and the relay 73
The signal generator 72 can insulate the protection circuit subsequent to the counter 82 from the DC voltage detection circuit 8, and the output voltage of the signal generator 72 is shaped into a rectangular wave by the relay 73 and counted by the counter 82. If the frequencies are the same, the detection time of the hunting operation is substantially the same regardless of the voltage value detected by the DC voltage detection circuit 8.

Embodiment 10 FIG. FIG. 10 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention. This converter device 94 has an up / down counter 88. The up / down counter 88 counts the voltage signal output by the signal generator 72 and has a clock generator (not shown), and counts down the clock generated by the clock generator.

The converter device 94 further includes a judgment value setting device 30 for setting a judgment value of the count value of the up / down counter 88 to reduce the proportional gain of the voltage controller 12a, and a judgment value set by the judgment value setting device 30. The value is compared with the count value counted by the up / down counter 88, and when the count value reaches the determination value, a signal for reducing the proportional gain of the voltage controller 12a and a signal for resetting the up / down counter 88 are respectively provided. And an output comparator 91 (eleventh comparator).

The converter 94 also receives a signal for reducing the proportional gain of the voltage controller 12a, and outputs the gain correction circuit 24 for reducing the proportional gain of the voltage controller 12a by a predetermined value and the signal generator 72. A reset circuit 88 is provided which causes the up / down counter 88 to start counting down the clock when a voltage signal is not input for a predetermined time or when a signal for resetting the up / down counter 88 is received. Other configurations are the same as those of converter device 81 described in the eighth embodiment, and a description thereof will not be repeated.

The operation of the converter device 94 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 continues hunting, the comparator 71
Compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setting device 19, and outputs an ON signal when the detected voltage value exceeds the set voltage value. The relay 73 is turned on by the ON signal output from the comparator 71, and the signal generator 72 outputs a predetermined voltage signal when the relay 73 is turned on. The up / down counter 88 counts a voltage signal that is a rectangular wave output from the signal generator 72.

On the other hand, the reset circuit 89 includes the signal generator 7
When the rectangular wave output from 2 is not inputted for a predetermined time, the up / down counter 88 starts counting down the clock. The up / down counter 88 terminates the countdown when counting down to 0, and stops counting down when a rectangular wave is input from the signal generator 72 while counting down, and stops counting at that time. Starts counting from.

The comparator 91 has an up / down counter 88
Is compared with the judgment value set by the judgment value setting unit 30, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller 12a is sent to the gain correction circuit 24, and the up-down counter A signal for resetting 88 is output to a reset circuit 89. The gain correction circuit 24 receives the signal for reducing the proportional gain of the voltage controller 12a, and reduces the proportional gain of the voltage controller 12a by a predetermined value. The reset circuit 89 receives the signal for resetting the up / down counter 88 and causes the up / down counter 88 to start counting down the clock. Other operations are the same as those of converter device 81 described in the eighth embodiment, and a description thereof will not be repeated.

As a result, when the voltage value detected by the DC voltage detection circuit 8 continues hunting, the converter device 94 can detect and suppress the hunting to protect the constituent devices. Also, the converter device 94
The comparator 71, the relay 72, and the signal generator 72 can insulate the protection circuit after the up / down counter 88 and the DC voltage detection circuit 8 from each other.
Is shaped into a square wave, and the up-down counter 8
Since the hunting frequency is the same, the detection time of the hunting operation is substantially the same regardless of the voltage value detected by the DC voltage detection circuit 8 if the hunting frequency is the same.

If hunting does not continue for a certain period of time, converter 94 sets up / down counter 8
8 causes the clock 8 to start counting down, so that even if hunting occurs temporarily due to the behavior of the loads of the inverters 3 to 5, it can be distinguished from hunting due to a change in the capacitance of the capacitor 18 and before the countdown ends. When a rectangular wave is input, the countdown is stopped and counting is started from the count value at that time. Therefore, even if hunting repeatedly occurs in a short time due to the behavior of the load of the inverters 3 to 5, the capacitor 18 Hunting due to the variation in the capacitance.

[0096]

According to the first aspect of the present invention, the converter supplies the DC power converted from the AC power, the DC voltage detection circuit detects the DC voltage output from the converter, and the reference circuit. Output the reference value of the DC voltage. The voltage controller amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit. The current detector detects an input current to the converter unit, and the current controller amplifies a deviation between the current value detected by the current detector and the output value of the voltage controller, and supplies the difference to the converter unit as a current control signal. When the voltage detected by the DC voltage detection circuit vibrates, the vibration determination voltage setting device sets a voltage for determining the vibration, and the first comparator determines the voltage detected by the DC voltage detection circuit and the vibration determination. The voltage setter compares the set voltage with a voltage set by the voltage setter, and outputs a voltage corresponding to the detected voltage exceeding the set voltage.

The gain determining section determines whether or not the proportional gain of the voltage controller should be reduced based on the voltage output from the first comparator. A signal for reducing by a predetermined value is output. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components.

According to the converter device of the second invention,
In the gain determination unit, the integrator integrates the voltage output by the first comparator, and the level setter outputs the voltage of the voltage output by the integrator.
Set the level at which the proportional gain of the voltage controller should be reduced. The second comparator compares the level set by the level setting unit with the voltage output by the integrator, and outputs a signal for reducing the proportional gain of the voltage controller by a predetermined value when the voltage reaches the level. And reset the integrator. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components.

According to the converter device of the third invention,
The gain determination unit is configured such that the waveform shaping circuit shapes the voltage output by the first comparator into a rectangular wave, the counter counts the square waves output by the waveform shaping circuit, and the determination value setting unit determines the count value of the counter. Of the voltage controller should be set to reduce the proportional gain. The third comparator compares the judgment value set by the judgment value setting device with the count value of the counter, and when the count value reaches the judgment value, a signal for reducing the proportional gain of the voltage controller by a predetermined value. Is output, and the counter is reset. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components. If the hunting frequency is the same, the detection time of the hunting operation is substantially the same regardless of the voltage value.

According to the converter device of the fourth aspect,
The reset circuit resets the counter when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time. Therefore, even if hunting occurs temporarily due to the behavior of the load of the inverter, the resetting circuit causes a change in the capacitance of the capacitor of the load. Hunting can be distinguished.

According to the converter device of the fifth aspect,
The gain determination unit is configured such that the waveform shaping circuit shapes the voltage output from the first comparator into a rectangular wave, the up / down counter counts the square wave output from the waveform shaping circuit, and outputs the clock generated by the clock generator. Count down. A judgment value setting device sets a judgment value of the count value of the up / down counter to reduce the proportional gain of the voltage controller, and a fourth comparator compares the set judgment value with the count value of the up / down counter. Then, when the count value reaches the determination value, a signal for reducing the proportional gain of the voltage controller by a predetermined value is output. The reset circuit causes the up / down counter to start counting down the clock when the fourth comparator outputs the signal and when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time.

Thus, when the hunting is continued at a low level of the output voltage, the hunting can be detected and suppressed to protect the components. If the hunting frequency is the same, the detection time of the hunting operation is substantially the same regardless of the voltage value. In addition, even if hunting occurs temporarily due to the behavior of the load of the inverter, it can be distinguished from hunting due to variation in the capacitance of the capacitor of the load, and hunting occurs repeatedly in a short time due to the behavior of the load of the inverter. Also,
It can be distinguished from hunting due to variation in the capacitance of the capacitor.

According to the converter device of the sixth aspect,
The converter supplies DC power converted from the AC power, the DC voltage detection circuit detects the DC voltage output by the converter, and the reference circuit outputs a reference value of the DC voltage. The voltage controller amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit. The current detector detects an input current to the converter unit, and the current controller amplifies a deviation between the current value detected by the current detector and the output value of the voltage controller, and provides the difference as a current control signal to the converter unit. When the voltage detected by the DC voltage detection circuit vibrates, the vibration determination voltage setting device sets a voltage for determining the vibration, and the deviation amplifier sets the voltage detected by the DC voltage detection circuit and the vibration determination voltage. When the detected voltage exceeds the set voltage, the difference between the two voltages is amplified and output as a rectangular wave voltage.

The gain judging section judges whether or not the proportional gain of the voltage controller should be reduced based on the rectangular wave voltage output from the deviation amplifier. A signal to reduce the value is output. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components.

According to the converter device of the seventh aspect,
In the gain determination unit, the integrator integrates the rectangular wave voltage output from the deviation amplifier, and the level setter sets a level at which the proportional gain of the voltage controller of the voltage output by the integrator is reduced. The fifth comparator compares the level set by the level setting unit with the voltage output by the integrator, and outputs a signal for reducing the proportional gain of the voltage controller by a predetermined value when the voltage reaches the level. And
Reset the integrator. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components.

According to the converter device of the eighth aspect,
In the gain determination unit, the counter counts the rectangular wave voltage output from the deviation amplifier, and the determination value setting unit sets a determination value of the count value of the counter to reduce the proportional gain of the voltage controller. The sixth comparator compares the judgment value set by the judgment value setting device with the count value of the counter, and when the count value reaches the judgment value, reduces the proportional gain of the voltage controller by a predetermined value. Is output. The reset circuit resets the counter when the sixth comparator outputs the signal and when the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time.

Thus, when the hunting is continued at a low level of the output voltage, the hunting can be detected and suppressed to protect the components. If the hunting frequency is the same, the detection time of the hunting operation becomes substantially the same irrespective of the voltage value, and even if the hunting occurs temporarily due to the behavior of the inverter load, the capacitor of the load is Hunting due to the variation in the capacitance.

According to the converter device of the ninth aspect,
In the gain determination unit, the up / down counter counts the rectangular wave voltage output from the deviation amplifier, counts down the clock generated by the clock generator, and the determination value setting unit determines the voltage of the count value of the up / down counter. Set the judgment value to reduce the proportional gain of the controller. The seventh comparator compares the judgment value set by the judgment value setting device with the count value of the up / down counter, and when the count value reaches the judgment value, reduces the proportional gain of the voltage controller by a predetermined value. The signal to be output is output. The reset circuit is
When the seventh comparator outputs the signal and when the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time, the up / down counter starts counting down the clock.

Thus, when the hunting is continued at a low level of the output voltage, the hunting can be detected and suppressed to protect the components. If the hunting frequency is the same, the detection time of the hunting operation is substantially the same regardless of the voltage value. In addition, even if hunting occurs temporarily due to the behavior of the load of the inverter, it can be distinguished from hunting due to variation in the capacitance of the capacitor of the load, and hunting occurs repeatedly in a short time due to the behavior of the load of the inverter. Also,
It can be distinguished from hunting due to variation in the capacitance of the capacitor.

According to the converter device of the tenth aspect, the converter unit supplies the DC power converted from the AC power, the DC voltage detection circuit detects the DC voltage output from the converter unit, and the reference circuit The reference value of the DC voltage is output. The voltage controller amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit. The current detector detects an input current to the converter unit, and the current controller amplifies a deviation between the current value detected by the current detector and the output value of the voltage controller, and provides the difference as a current control signal to the converter unit.
When the voltage detected by the DC voltage detection circuit vibrates, the vibration determination voltage setting device sets a voltage for determining the vibration. The eighth comparator determines the voltage detected by the DC voltage detection circuit and the vibration determination. A voltage setter compares the voltage with the set voltage, and outputs an ON signal when the detected voltage exceeds the set voltage. The relay is turned on by the ON signal output by the eighth comparator, and generates a predetermined voltage signal when the signal generator semiconductor and the relay are turned on.

The gain determination section determines whether or not to reduce the proportional gain of the voltage controller based on the voltage signal generated by the signal generator. A signal for reducing by a predetermined value is output. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components. Further, if the protection circuit and the DC voltage detection circuit can be insulated and the hunting frequency is the same, the detection time of the hunting operation becomes substantially the same regardless of the voltage value.

According to the converter device of the eleventh aspect, in the gain determining section, the integrator integrates the voltage signal output from the signal generator, and the level setting section controls the voltage controller of the voltage output from the integrator. Set the level to reduce the proportional gain of. The ninth comparator compares the level set by the level setting unit with the voltage output by the integrator, and outputs a signal for reducing the proportional gain of the voltage controller by a predetermined value when the voltage reaches the level. And reset the integrator. Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components.
Further, if the protection circuit and the DC voltage detection circuit can be insulated and the hunting frequency is the same, the detection time of the hunting operation becomes substantially the same regardless of the voltage value.

According to the converter device of the twelfth aspect, in the gain determination section, the counter counts the voltage signal output by the signal generator, and the determination value setting section determines that the count value of the counter is proportional to the voltage controller. Set the judgment value to reduce the gain. The tenth comparator compares the judgment value set by the judgment value setting device with the count value of the counter, and outputs a signal for reducing the proportional gain of the voltage controller when the count value reaches the judgment value. Moreover, the counter is reset. Thus, when the output voltage is low and the hunting continues, the hunting can be detected and suppressed to protect the component devices. Further, if the protection circuit and the DC voltage detection circuit can be insulated and the hunting frequency is the same, the detection time of the hunting operation becomes substantially the same regardless of the voltage value.

According to the converter device of the thirteenth aspect, in the gain determining section, the up / down counter counts the voltage signal output by the signal generator and counts down the clock generated by the clock generator, and determines the gain. A value setting unit sets a determination value of the count value of the up / down counter to reduce the proportional gain of the voltage controller.
The eleventh comparator compares the determination value set by the determination value setting device with the count value of the up / down counter, and when the count value reaches the determination value, outputs a signal for reducing the proportional gain of the voltage controller. Output. The reset circuit has a first
When the comparator outputs the signal and when the voltage signal output from the signal generator is not input for a predetermined time, the up / down counter starts counting down the clock.

Thus, when the output voltage continues to hunt at a low level, the hunting can be detected and suppressed to protect the components. Further, if the protection circuit and the DC voltage detection circuit can be insulated and the hunting frequency is the same, the detection time of the hunting operation becomes substantially the same regardless of the voltage value. In addition, even if hunting occurs temporarily due to the behavior of the load of the inverter, it can be distinguished from hunting due to variation in the capacitance of the capacitor of the load, and hunting occurs repeatedly in a short time due to the behavior of the load of the inverter. This can also be distinguished from hunting due to variation in the capacitance of the capacitor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 2 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 3 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 4 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 5 is a block diagram illustrating a configuration of an embodiment of a converter device according to the present invention.

FIG. 6 is a block diagram illustrating a configuration of an embodiment of a converter device according to the present invention.

FIG. 7 is a block diagram illustrating a configuration of an embodiment of a converter device according to the present invention.

FIG. 8 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 9 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 10 is a block diagram showing a configuration of an embodiment of a converter device according to the present invention.

FIG. 11 is a block diagram illustrating a configuration example of a conventional converter device.

[Explanation of symbols]

1 Commercial AC power supply, 3-5 inverter, 6 CT, 7
Current detector, 8 DC voltage detection circuit, 10 converter main circuit (converter section), 11 reference circuit, 12a
Voltage controller, 14 Current controller, 18
(Smoothing) capacitor, 19 Hunting judgment voltage setting device (vibration judgment voltage setting device), 20, 23, 31, 39, 4
5, 52, 60, 67, 71, 78, 84, 91 comparator, 21, 50, 76 integrator, 22 level setter,
24 gain correction circuit, 25 interlock circuit, 2
7, 34, 42, 48, 55, 63, 70, 81, 8
7, 94 converter device, 28, 35 waveform shaping circuit, 29, 37, 58, 82 counter, 30 judgment value setting device, 36, 57, 64, 89 reset circuit, 4
3,65,88 Up / down counter, 49,56
Deviation amplifier, 72 signal generator, 73 relay, 74
Relay contact, 75 insulation comparator.

Claims (13)

[Claims] A converter for supplying DC power converted from AC power, a DC voltage detection circuit for detecting a DC voltage output from the converter, a reference circuit for outputting a reference value of the DC voltage, A voltage controller that amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit, a current detector that detects an input current to the converter unit, and the current detector Amplifies the deviation between the detected current value and the output value of the voltage controller, and provides a current controller to the converter section as a current control signal. When the voltage detected by the DC voltage detection circuit vibrates, the vibration is determined. A vibration determination voltage setting device that sets a voltage for performing the operation, a voltage detected by the DC voltage detection circuit is compared with a voltage set by the vibration determination voltage setting device, A first comparator that outputs a voltage corresponding to the amount by which the detected voltage exceeds the set voltage, and whether to reduce a proportional gain of the voltage controller based on the voltage output by the first comparator. A converter that outputs a signal for reducing the proportional gain by a predetermined value when it is determined that the proportional gain should be reduced. 2. A gain determining section, comprising: an integrator for integrating a voltage output by a first comparator;
A level setting device for setting a level to reduce the proportional gain of the voltage controller, comparing the level set by the level setting device with the voltage output by the integrator, and when the voltage reaches the level, The converter device according to claim 1, further comprising a second comparator that outputs a signal for reducing the proportional gain by a predetermined value and that resets the integrator. 3. A gain determining section comprising: a waveform shaping circuit for shaping the output of the first comparator into a rectangular wave; a counter for counting the square wave output from the waveform shaping circuit; and a voltage of the count value of the counter. A judgment value setting device for setting a judgment value for reducing the proportional gain of the controller, and comparing the judgment value set by the judgment value setting device with the count value of the counter, and the count value reaches the judgment value. 2. The converter device according to claim 1, further comprising a third comparator that outputs a signal for reducing the proportional gain by a predetermined value and resets the counter. 4. The converter device according to claim 3, further comprising a reset circuit for resetting a counter when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time. 5. The gain determining section has a waveform shaping circuit for shaping the output of the first comparator into a rectangular wave, and a clock generator, counts the square waves output by the waveform shaping circuit, and generates a clock signal. An up-down counter that counts down a clock in which a clock has occurred, a judgment value setting device that sets a judgment value of the count value of the up / down counter to reduce the proportional gain of the voltage controller, and a judgment value set by the judgment value setting device. A fourth comparator for comparing a value with a count value of the up / down counter, and outputting a signal for reducing the proportional gain by a predetermined value when the count value reaches the determination value; When the counter outputs the signal and when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time, the up / down counter starts counting down the clock. And a set circuit.
The converter device as described. 6. A converter for supplying DC power converted from AC power, a DC voltage detection circuit for detecting a DC voltage output by the converter, a reference circuit for outputting a reference value of the DC voltage, A voltage controller that amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit, a current detector that detects an input current to the converter unit, and the current detector Amplifies the deviation between the detected current value and the output value of the voltage controller, and provides a current controller to the converter section as a current control signal. When the voltage detected by the DC voltage detection circuit vibrates, the vibration is determined. A vibration determination voltage setting device that sets a voltage for performing the operation, a voltage detected by the DC voltage detection circuit is compared with a voltage set by the vibration determination voltage setting device, When the detected voltage exceeds the set voltage, a deviation amplifier that amplifies a deviation between the two voltages and outputs the amplified voltage as a rectangular wave voltage, and a proportional gain of the voltage controller based on the rectangular wave voltage output by the deviation amplifier. A converter device comprising: a gain determination unit configured to determine whether or not to reduce the gain, and to output a signal for reducing the proportional gain by a predetermined value when the reduction is determined. 7. A gain judging unit, comprising: an integrator for integrating a rectangular wave voltage output by the deviation amplifier; and a level setting unit for setting a level of the voltage output by the integrator for reducing a proportional gain of the voltage controller. And comparing the level set by the level setter with the voltage output by the integrator,
7. The converter device according to claim 6, further comprising: a fifth comparator that outputs a signal for reducing the proportional gain by a predetermined value when the voltage reaches the level, and that resets the integrator. 8. A gain judging section, comprising: a counter for counting the rectangular wave voltage output by the deviation amplifier; a judgment value setting device for setting a judgment value of the count value of the counter to reduce a proportional gain of the voltage controller; Comparing the judgment value set by the judgment value setting device with the count value of the counter, and outputting a signal for reducing the proportional gain by a predetermined value when the count value reaches the judgment value. The converter device according to claim 6, further comprising: a comparator; and a reset circuit that resets the counter when the sixth comparator outputs the signal and when the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time. . 9. A gain judging section counts the rectangular wave voltage output from the deviation amplifier, has a clock generator, and counts down a clock generated by the clock generator. A judgment value setting device for setting a judgment value for reducing the proportional gain of the voltage controller of the count value of the counter, and comparing the judgment value set by the judgment value setting device with the count value of the up / down counter, Outputting a signal for reducing the proportional gain by a predetermined value when the count value reaches the determination value;
A comparator, and a reset circuit that causes the up / down counter to start counting down the clock when the seventh comparator outputs the signal and when the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time. The converter device according to claim 6. 10. A converter for supplying DC power converted from AC power, a DC voltage detection circuit for detecting a DC voltage output by the converter, a reference circuit for outputting a reference value of the DC voltage, A voltage controller that amplifies and outputs a deviation between the reference value output by the reference circuit and the DC voltage value detected by the DC voltage detection circuit, a current detector that detects an input current to the converter unit, and the current detector Amplifies the deviation between the detected current value and the output value of the voltage controller, and provides a current controller to the converter section as a current control signal. When the voltage detected by the DC voltage detection circuit vibrates, the vibration is determined. A voltage for setting a voltage for performing the operation, and comparing the voltage detected by the DC voltage detection circuit with the voltage set by the vibration determination voltage setter. An eighth comparator that outputs an ON signal when the detected voltage exceeds the set voltage, a relay that is turned on by the ON signal output by the eighth comparator, and when the relay is turned on. A signal generator for generating a predetermined voltage signal; and determining whether to reduce the proportional gain of the voltage controller based on the voltage signal generated by the signal generator. A converter for outputting a signal for reducing the proportional gain by a predetermined value. 11. A gain judging unit, comprising: an integrator for integrating a voltage signal output by a signal generator; and a level setting unit for setting a level of the voltage output by the integrator for reducing a proportional gain of the voltage controller. And comparing the level set by the level setter with the voltage output by the integrator,
The converter device according to claim 10, further comprising: a ninth comparator that outputs a signal for reducing the proportional gain by a predetermined value when the voltage reaches the level, and that resets the integrator. 12. A gain determination unit comprising: a counter for counting a voltage signal output by a signal generator; and a determination value setting unit for setting a determination value of a count value of the counter to reduce a proportional gain of a voltage controller. Comparing the judgment value set by the judgment value setting device with the count value of the counter, and when the count value reaches the judgment value, outputs a signal for reducing the proportional gain; The converter device according to claim 10, further comprising: a tenth comparator for resetting a value. 13. The gain determining section counts the voltage signal output by the signal generator, and further includes a clock generator.
An up / down counter for counting down a clock generated by the clock generator, a judgment value setting device for setting a judgment value of a count value of the up / down counter to reduce a proportional gain of a voltage controller, and a judgment value setting device The set value is compared with the count value of the up / down counter, and when the count value reaches the judgment value,
An eleventh comparator for outputting a signal for reducing the proportional gain, and when the eleventh comparator outputs the signal and when the voltage signal output by the signal generator is not input for a predetermined time, the up / down counter The converter device according to claim 10, further comprising: a reset circuit that starts counting down of the clock.