JP3418779B2 - Converter device - Google Patents

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 supplying DC power converted from AC power to a load having a capacitor.

[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 is
The commercial AC power supply 1 supplies 3-phase AC power to a main circuit bridge 9 made of a semiconductor, and the main circuit bridge 9 rectifies the supplied 3-phase AC power into DC power and outputs the DC power. The DC power output from the main circuit bridge 9 is given to the inverters 3, 4 and 5 each having the smoothing capacitor 18. Among the three-phase input lines of the main circuit bridge 9, the CT6 (Current Transf
ormer) are respectively attached, the outputs of these two CT6 are given to the current detector 7, and the input current to the main circuit bridge 9 is detected.

A DC voltage detection circuit 8 is connected between the output lines of the main circuit bridge 9 and detects the DC voltage output from the converter device 2. The main circuit bridge 9, CT 6 and DC voltage detection circuit 8 constitute a converter main circuit 10. The DC voltage value detected by the DC voltage detection circuit 8 is given to the voltage controller 12 and the overvoltage detection circuit 13, and the voltage controller 12 gives this DC voltage value and the reference value of the DC voltage output by the converter device 2. The deviation from the reference DC voltage value from the reference circuit 11 is amplified and output. The overvoltage detection circuit 13 gives 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 given to the current controller 14 and the overcurrent detection circuit 15, and the current controller 14 amplifies the deviation between this current value and the output of the voltage controller 12 to obtain the current value. It is given to the main circuit bridge 9 as a control signal. The overcurrent detection circuit 15 outputs a signal for stopping 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 receiving a stop signal from the overvoltage detection circuit 13 or the overcurrent detection circuit 15.

The operation of the converter device 2 having such a configuration will be described below. The converter device 2 supplies direct-current power to the voltage source inverters 3 to 5 including the capacitor load 18, and controls the direct-current voltage to be constant against variations in the load. That is, the output voltage is the reference circuit 11
Is controlled by the voltage controller 12 so that it becomes the reference DC voltage value output by.

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 and uses it as the current instruction signal, when the load of the inverter 3 suddenly increases, the detection value of the DC voltage detection circuit 8 is increased. And the reference DC voltage value increase, and the reference current value output to the current controller 14 increases. Therefore, the current instruction value that the current controller 14 gives to the main circuit bridge 9 increases,
The main circuit bridge 9 operates so as to supply a large amount of current to the capacitor 18 and reduce fluctuations in the DC voltage detected by the DC voltage detection circuit 8.

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 stable. 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 given to the interlock circuit 16 from the overvoltage detection circuit 13, and the interlock circuit 16 stops the main circuit bridge 9 and the converter main circuit 10 to protect the constituent devices.

However, when the 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 as it is, the temperature of the capacitor 18, which is a load, may be increased by the ripple current and may be damaged. The overcurrent detection circuit 15 gives a signal for stopping to the interlock circuit 16 when the current value from the current detector 7 reaches a preset current value. The circuit bridge 9 is stopped and the converter main circuit 10 is stopped to protect the constituent devices.

[0009]

As described above, in the conventional converter device 2, the interlock circuit 16 is activated and stopped when the overvoltage more than the overvoltage set value occurs even once. Even if voltage fluctuation occurs due to load fluctuation of 5, the problem occurs that the overvoltage set value is set low to stop, and conversely, if the overvoltage set value is set high, the voltage range in which the interlock circuit 16 does not operate There is a problem that the capacitor 18 is damaged due to the hunting. The present invention has been made in view of the above-described circumstances, it is possible to stop protection from overvoltage and low voltage, and even if voltage hunting that does not reach these overvoltage and low voltage occurs, its frequency It is an object of the present invention to provide a converter device that can detect and stop regardless of the above.

[0010]

SUMMARY OF THE INVENTION A converter device according to a first aspect of the present invention is a converter unit for supplying a load having a capacitor with DC power converted from AC power, and a DC unit for detecting a DC voltage output by the converter unit. A voltage detection circuit, an instantaneous overvoltage setting unit that sets an overvoltage of the voltage detected by the DC voltage detection circuit that the converter unit should momentarily stop, and a low voltage of the voltage that the converter unit should momentarily stop. The instantaneous low voltage setting device, the voltage detected by the DC voltage detection circuit, the overvoltage set by the instantaneous overvoltage setting device and the low voltage set by the instantaneous low voltage setting device are compared, and the voltage is the overvoltage or When the low voltage is reached, the first comparator that outputs a signal that causes the converter unit to stop instantaneously and the DC voltage detection circuit detect
The voltage for judging the vibration when the voltage vibrates.
The vibration judgment voltage setting device and the DC voltage detection circuit
The voltage detected by the road and the vibration determination voltage setter set
Compared with the voltage, the detected voltage is the set voltage
A second comparator that outputs a voltage according to the amount exceeding
The converter is stopped based on the voltage output from the comparator.
When it is decided that it should be stopped and it is decided that it should be stopped,
Stop judgment that outputs a signal to stop the converter section
And an interlock circuit that stops the converter unit in response to a signal output from the first comparator or the stop determination unit .

[0011]

In the converter device according to the second aspect of the present invention, the stop determination unit sets the integrator for integrating the voltage output by the second comparator and the level of the voltage output by the integrator for stopping the converter unit. Comparing the stop level setting device and the level set by the stop level setting device with the voltage output by the integrator, and when the voltage reaches the level,
And a third comparator that outputs a signal for stopping the converter unit.

In the converter device according to the third aspect of the present invention, the stop determination unit includes a waveform shaping circuit that shapes the voltage output from the second comparator into a rectangular wave, and a counter that counts the rectangular wave output from the waveform shaping circuit. , A stop judgment value setting device that sets a judgment value for stopping the converter unit, of the count value of the counter, and a judgment value set by the stop judgment value setting device and the count value of the counter, and And a fourth comparator that outputs a signal for stopping the converter unit when the numerical value reaches the determination value.

A converter device according to a fourth aspect of the present invention includes a reset circuit for resetting a counter when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time.

In the converter device according to the fifth aspect of the present invention, the stop determination unit has a waveform shaping circuit for shaping the voltage output from the second comparator into a rectangular wave and a clock generator, and the waveform shaping circuit outputs the waveform. An up / down counter that counts a rectangular wave and counts down a clock generated by a clock generator; a stop determination value setting device that sets a determination value of the count value of the up / down counter that should stop the converter unit; A fifth comparator that compares the judgment value set by the stop judgment value setter with the count value of the up / down counter, and outputs a signal for stopping the converter unit when the count value reaches the judgment value. And a reset circuit for causing the up-down counter to start counting down the clock when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time. Characterized in that it comprises a.

A converter device according to a sixth aspect of the present invention is a converter unit for supplying a DC power converted from AC power to a load having a capacitor, a DC voltage detection circuit for detecting a DC voltage output from the converter unit, An instantaneous overvoltage setter for setting an overvoltage of the voltage detected by the DC voltage detection circuit that the converter should stop for an instant, and an instantaneous low voltage setter for setting a low voltage of the voltage that the converter should stop for an instant And comparing the voltage detected by the DC voltage detection circuit with the overvoltage set by the instantaneous overvoltage setting device and the low voltage set by the instantaneous low voltage setting device, and the voltage reaches the overvoltage or the low voltage. At times, by amplifying the deviation between the voltage and the overvoltage or the low voltage,
A first deviation amplifier which outputs as a signal for instantaneously stopping the converter section, and an electric current detected by the DC voltage detection circuit.
When the pressure vibrates, set the voltage to judge the vibration.
Vibration determination voltage setting device and the DC voltage detection circuit
Detected voltage and voltage set by the vibration judgment voltage setting device
And the detected voltage exceeds the set voltage.
The difference between the two voltages is amplified and output as a rectangular wave voltage.
Output second deviation amplifier and the quadrature output from the second deviation amplifier.
Determine whether to stop the converter based on the waveform voltage
If you decide to turn it off and stop it,
And a stop determination unit that outputs a signal that stops the switching unit, and an interlock circuit that stops the converter unit when receiving the signal output from the first deviation amplifier or the stop determination unit .

[0017]

In the converter device according to the seventh aspect of the present invention, the stop determination unit includes an integrator that integrates the rectangular wave voltage output by the second deviation amplifier and a level of the voltage output by the integrator that should stop the converter unit. Comparing the level set by the stop level setter and the voltage output by the integrator, and a signal for stopping the converter unit when the voltage reaches the level. And a sixth comparator for outputting.

In the converter device according to the eighth aspect of the present invention, the stop determination unit sets a counter that counts the rectangular wave voltage output by the second deviation amplifier and a determination value of the count value of the counter that should stop the converter unit. Stop judgment value setting device
A seventh comparison circuit that compares the determination value set by the stop determination value setting device with the count value of the counter, and outputs a signal to stop the converter unit when the count value reaches the determination value.
A comparator and a reset circuit that resets the counter when the rectangular wave voltage output from the second deviation amplifier is not input for a predetermined time.

In the converter device according to the ninth aspect of the present invention, the stop determination unit counts the rectangular wave voltage output by the second deviation amplifier, and has a clock generator, and outputs the clock generated by the clock generator. An up / down counter that counts down, a stop determination value setter that sets a determination value of the count value of the up / down counter that should stop the converter unit, a determination value set by the stop determination value setting device, and the up / down counter. Of the rectangular wave voltage output from the second deviation amplifier and the eighth comparator that outputs a signal to stop the converter when the count value reaches the determination value. And a reset circuit for causing the up / down counter to start counting down the clock when not input.

The converter device according to a tenth invention, con
DC power converted from AC power to a load with a capacitor
And a converter that supplies the
A DC voltage detection circuit for detecting a DC voltage and the DC voltage detection circuit.
Instantaneous stop of the converter part of the voltage detected by the output circuit
Instantaneous overvoltage setting device for setting the overvoltage to be
Set a low voltage that the converter section should stop for an instant.
Instantaneous low voltage setting device and the DC voltage detection circuit
Voltage and the overvoltage set by the instantaneous overvoltage setter and
Compare the low voltage set by the instantaneous low voltage setting device,
When the voltage reaches the overvoltage or the undervoltage, the
First comparison that outputs a signal that causes the converter to stop instantaneously
And a vibration determination voltage setting device that sets a voltage for determining the vibration when the voltage detected by the DC voltage detection circuit vibrates, a voltage detected by the DC voltage detection circuit, and the vibration determination voltage Compare the voltage set by the setter,
A ninth comparator which outputs an ON signal when the detected voltage exceeds the set voltage, a relay which is turned ON by an ON signal output by the ninth comparator, and when the relay is ON. A signal generator that generates a predetermined voltage signal, and whether to stop the converter unit based on the voltage signal generated by the signal generator. When it is determined that the converter unit should be stopped, the converter unit is stopped. A stop determination unit that outputs a signal that causes the converter to operate and an interlock circuit that stops the converter unit in response to the signal output from the first comparator or the stop determination unit are provided .

In the converter device according to the eleventh aspect of the invention, the stop determination unit sets the integrator for integrating the voltage signal output by the signal generator and the level of the voltage output by the integrator for stopping the converter unit. Comparing the level set by the stop level setter and the voltage output by the integrator, and outputs a signal for stopping the converter unit when the voltage reaches the level. First
And a zero comparator.

In the converter device according to the twelfth aspect of the invention, the stop judging unit sets the counter for counting the voltage signal output from the signal generator and the stop value for setting the judgment value of the counter value for stopping the converter unit. A judgment value setter, comparing the judgment value set by the stop judgment value setter with the count value of the counter, and when the count value reaches the judgment value,
An eleventh comparator that outputs a signal for stopping the converter unit is provided.

In the converter device according to the thirteenth aspect of the present invention, the stop determination unit counts the voltage signal output by the signal generator, and has a clock generator, and counts down the clock generated by the clock generator. An up / down counter, a stop determination value setter for setting a determination value for stopping the converter of the count value of the up / down counter, a determination value set by the stop determination value setter, and a sum of the up / down counter. A twelfth comparator that compares a numerical value and outputs a signal to stop the converter when the count value reaches the determination value, and the voltage signal output from the signal generator is not input for a predetermined time. And a reset circuit for causing the up / down counter to start counting down the clock.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings showing the embodiments thereof. Embodiment 1. FIG. 1 is a block diagram showing a configuration of an embodiment of a converter device according to the first to third inventions. The converter device 28 includes a main circuit bridge 9 made of a semiconductor that rectifies the three-phase AC power supplied from the commercial AC power supply 1 into DC power and outputs the DC power. The DC power output by the main circuit bridge 9 is smoothed. It is applied to inverters 3, 4 and 5 each having a capacitor 18. Of the three-phase input lines of the main circuit bridge 9, CT6 (Current Transformer) for detecting an alternating current is attached to each of the two-phase input lines, and the outputs of these two CT6 are the current detector 7
Input current to the main circuit bridge 9 is detected.

The converter device 28 also includes a DC voltage detection circuit 8 which is connected between the output lines of the main circuit bridge 9 and detects the DC voltage output by the converter device 28.
The main circuit bridge 9, CT6 and DC voltage detection circuit 8 are
The converter main circuit 10 is configured.

The converter device 28 is also provided with the DC voltage value detected by the DC voltage detection circuit 8, and the reference DC from the reference circuit 11 which gives this DC voltage value and the reference value of the DC voltage output by the converter device 28. The voltage controller 12 that amplifies and outputs the deviation from the voltage value and the current value detected by the current detector 7 are given, and the deviation between the current value and the output of the voltage controller 12 is amplified and used as a current control signal. Current controller 14 for circuit bridge 9
And an interlock circuit 16 for stopping the main circuit bridge 9 (converter main circuit 10) and a current value detected by the current detector 7, and when the current value reaches a preset current value. And an overcurrent detection circuit 15 for supplying a signal for stopping to the interlock circuit 16.

The converter device 28 also includes an instantaneous overvoltage setter 21 for setting an overvoltage value of the DC voltage value detected by the DC voltage detection circuit 8 at which the main circuit bridge 9 as the converter should be stopped instantaneously, and the DC voltage. An instantaneous low voltage setter 22 for setting a low voltage value of the voltage value at which the main circuit bridge 9 should stop instantaneously, a voltage value detected by the DC voltage detection circuit 8 and an overvoltage value and an instantaneous value set by the instantaneous overvoltage setter 21. The low voltage value set by the low voltage setting device 22 is compared, and when the detected voltage value reaches the overvoltage value or the low voltage value, a signal for instantaneously stopping the main circuit bridge 9 is output to the interlock circuit 16. And a comparator 20 (first and second comparators).

In the converter device 28, when the voltage value detected by the DC voltage detection circuit 8 vibrates (hunts), a vibration (hunting) determination voltage setter 19 sets a voltage value for determining the vibration. Equipped with a 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 outputs a voltage corresponding to the amount by which the detected voltage value exceeds the set voltage value. The converter device 28 also includes an integrator 23 that integrates the voltage output by the comparator 20, and a stop level setting device 24 that sets the level of the voltage output by the integrator 23 that should stop the main circuit bridge 9. The level set by the stop level setting unit 24 is compared with the voltage output by the integrator 23, and when the voltage reaches the level, the interlock circuit 1 outputs a signal for stopping the main circuit bridge 9.
6 and a comparator 25 (third comparator) that outputs the signal to the output terminal 6.

The operation of the converter device 28 having such a configuration will be described below. The converter device 28 supplies direct-current power to the voltage source inverters 3 to 5 including the capacitor load 18, and controls the direct-current voltage to be constant against variations in the load. That is, the voltage controller 12 controls the output voltage to be the reference DC voltage value output by 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. 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 and uses it as the current instruction signal, when the load of the inverter 3 suddenly increases, the detection value of the DC voltage detection circuit 8 is increased. And the reference DC voltage value increase, and the reference current value output to the current controller 14 increases. Therefore, the current instruction value that the current controller 14 gives to the main circuit bridge 9 increases,
The main circuit bridge 9 operates so as to supply a large amount of current to the capacitor 18 and reduce fluctuations in the DC voltage detected by the DC voltage detection circuit 8.

The overcurrent detection circuit 15 gives a signal for stopping to the interlock circuit 16 when the current value from the current detector 7 reaches a preset overcurrent value,
The interlock circuit 16 stops the main circuit bridge 9 and the converter main circuit 10 to protect the constituent devices.

The amplification factor of the voltage controller 12 is calculated on the basis of the capacity of the capacitor 18 or the like serving as a load, and is set so that the DC voltage control system is stable. Here, when the capacitance of the capacitor 18 changes, particularly 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, the DC voltage detection circuit 8
When the voltage value detected by the counter reaches the overvoltage value set by the instantaneous overvoltage setting unit 21, the comparator 20 outputs a signal for instantaneously stopping the main circuit bridge 9 to the interlock circuit 16 and the interlock circuit 16 Is the main circuit bridge 9
(Converter main circuit 10) is stopped to protect the components including the load capacitor 18.

Further, when the voltage value detected by the DC voltage detection circuit 8 reaches the low voltage value set by the instantaneous low voltage setting unit 22, the comparator 20 outputs a signal for stopping the main circuit bridge 9 for an instant. It outputs to the interlock circuit 16, and the interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10), and the inverters 3-5 which are loads.
Protect the components from abnormal operation of overcurrent due to lack of DC voltage.

The voltage value detected by the DC voltage detection circuit 8 is
When the overvoltage value set by the instantaneous overvoltage setting device 21 and the low voltage value set by the instantaneous low voltage setting device 22 are not reached and the hunting continues, the comparator 20 detects the DC voltage detection circuit 8. The voltage value is compared with the voltage value set by the hunting determination voltage setter 19, and a voltage corresponding to the amount by which the detected voltage value exceeds the set voltage value is output. The voltage output from the comparator 20 is integrated by the integrator 23 and output. The voltage integrated and output by the integrator 23 is compared with the level set by the stop level setting unit 24 by the comparator 25, and when the level is reached, the comparator 25
A signal for stopping the main circuit bridge 9 is output to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.

The detection time of the hunting operation varies depending on the amount of voltage exceeding the voltage value set by the hunting determination voltage setting device 19 and its frequency. This is because the integrator 23 is used to operate when the integrated value exceeds the level set by the stop level setting unit 24.
If the ripple is large, the detection time is short, and if the ripple is small, the detection time is long. The detection time also varies depending on the frequency of the hunting operation. However, the capacitor 18 can be protected by appropriately setting the setting level of the stop level setting unit 24 according to the characteristics of the capacitor 18.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 28 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 and the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

Embodiment 2. FIG. 2 is a block diagram showing a configuration of an embodiment of a converter device according to the fourth invention. In this converter device 35, 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 minutes
Waveform shaping circuit 29 for shaping a rectangular wave and waveform shaping circuit 2
And a counter 30 for counting the rectangular waves output by

The converter device 35 also includes a counter 3
A stop judgment value setter 31 for setting a judgment value for stopping the main circuit bridge 9 having a count value of 0 is compared with the judgment value set by the stop judgment value setter 31 and the count value of the counter 30 to calculate the total. A comparator 32 (fourth comparator) that outputs a signal for stopping the main circuit bridge 9 to the interlock circuit 16 when the numerical value reaches the determination value. Other configurations are the same as the configurations of converter device 28 described in the first embodiment, and description thereof will be omitted.

The operation of the converter device 35 having such a configuration will be described below. In the converter device 35, 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 the detected voltage value exceeding the set voltage value is output. The waveform shaping circuit 29 shapes the voltage output from the comparator 20 into a rectangular wave and outputs the rectangular wave. Counter 30
Counts the rectangular wave output from the waveform shaping circuit 29.

The comparator 32 compares the count value of the counter 30 with the judgment value set by the stop judgment value setting device 31, and when the count value reaches the judgment value, outputs a signal for stopping the main circuit bridge 9. It outputs to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.
Other operations are the same as the operations of converter device 28 described in the first embodiment, and therefore description thereof will be omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 35 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 and the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped 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 29 and counted by the counter 30, if the hunting frequency is the same, the detection time of the hunting operation is the DC voltage detection circuit 8. Are substantially the same regardless of the voltage value detected by.

Embodiment 3. FIG. 3 is a block diagram showing a configuration of an embodiment of a converter device according to the fifth invention. In this converter device 43, 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 minutes
Waveform shaping circuit 36 for shaping into a rectangular wave, and waveform shaping circuit 3
A counter 38 that counts the rectangular wave output by 6 and a reset circuit 37 that resets the counter 38 when the rectangular wave output by the waveform shaping circuit 36 is not input for a predetermined time.

The converter device 43 also includes a counter 3
The stop judgment value setter 31 for setting the judgment value for stopping the main circuit bridge 9 of the count value of 8 and the judgment value set by the stop judgment value setter 31 are compared with the count value of the counter 38 to calculate the total. The comparator 32 outputs a signal for stopping the main circuit bridge 9 to the interlock circuit 16 when the numerical value reaches the judgment value. Other configurations are the same as the configurations of converter device 28 described in the first embodiment, and description thereof will be omitted.

The operation of the converter device 43 having such a configuration will be described below. In the converter device 43, 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 the detected voltage value exceeding the set voltage value is output. The waveform shaping circuit 36 shapes this voltage output from the comparator 20 into a rectangular wave and outputs it. Counter 38
Counts the rectangular wave output from the waveform shaping circuit 36. On the other hand, the reset circuit 37 resets the counter 38 when the rectangular wave output from the waveform shaping circuit 36 is not input for a predetermined time.

The comparator 32 compares the count value of the counter 38 with the judgment value set by the stop judgment value setting device 31, and outputs a signal for stopping the main circuit bridge 9 when the count value reaches the judgment value. It outputs to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.
Other operations are the same as the operations of converter device 28 described in the first embodiment, and therefore description thereof will be omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 43 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 and the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped 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 36 and counted by the counter 38, if the hunting frequency is the same,
The detection time of the hunting operation becomes substantially the same regardless of the voltage value detected by the DC voltage detection circuit 8, and the counter 38 is reset when the hunting does not continue for a certain period of time. Even if hunting occurs temporarily due to the behavior, it can be distinguished from hunting due to the capacitance variation of the capacitor 18.

Fourth Embodiment FIG. 4 is a block diagram showing a configuration of an embodiment of a converter device according to the sixth invention. In this converter device 49, 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 minutes
An up / down counter that has a waveform shaping circuit 36 for shaping a rectangular wave and a clock generator (not shown), counts the rectangular wave output by the waveform shaping circuit 36, and counts down the clock generated by the clock generator. 44, and a reset circuit 37 that causes the up / down counter 44 to start clock countdown when the rectangular wave output from the waveform shaping circuit 36 is not input for a predetermined time.

The converter device 49 also includes a stop determination value setting unit 45 for setting a determination value of the count value of the up / down counter 44 for stopping the main circuit bridge 9 and a determination set by the stop determination value setting unit 45. A comparator 46 (fifth comparator) which compares the value with the count value of the up / down counter 44 and outputs a signal for stopping the main circuit bridge 9 when the count value reaches the determination value is provided. . Other configurations are the same as the configurations of converter device 28 described in the first embodiment, and description thereof will be omitted.

The operation of the converter device 49 having such a configuration will be described below. In the converter device 49, 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 the detected voltage value exceeding the set voltage value is output. The waveform shaping circuit 36 shapes and outputs this voltage output from the comparator 20 into a rectangular wave, and the up / down counter 44 counts the rectangular wave output from the waveform shaping circuit 36.

On the other hand, the reset circuit 37, when the rectangular wave output from the waveform shaping circuit 36 is not input for a predetermined time,
The up / down counter 44 starts the clock countdown. The up-down counter 44 terminates the countdown when it counts down to 0, and when the rectangular wave is input from the waveform shaping circuit 36 during the countdown, stops the countdown and returns the count value at that time. Start counting from.

The comparator 46 includes an up / down counter 44.
And the judgment value set by the stop judgment value setter 45 are compared, and when the count value reaches the judgment value, a signal for stopping the main circuit bridge 9 is output to the interlock circuit 16. The interlock circuit 16 includes the main circuit bridge 9
The (converter main circuit 10) is stopped to prevent the load capacitor 18 from being damaged due to the temperature rise due to the ripple current. Other operations are similar to those of converter device 28 described in the first embodiment, and
The description is omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 49 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 and the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped 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 36 and is counted by the up / down counter 44, 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 the hunting does not continue for a certain period of time, the up / down counter 44 starts counting down the clock. Therefore, even if the hunting occurs temporarily due to the load behavior of the inverters 3 to 5, the hunting due to the capacitance variation of the capacitor 18 occurs. When a rectangular wave is input before the countdown ends, the countdown is stopped and counting is started from the count value at that time. Therefore, the behavior of the loads of the inverters 3 to 5 can be distinguished. Therefore, even if the hunting is repeatedly generated in a short time, it can be distinguished from the hunting due to the capacitance variation 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 seventh to ninth inventions. The converter device 56 includes an instantaneous overvoltage setting device 21 for setting an overvoltage value of the DC voltage value detected by the DC voltage detection circuit 8 at which the main circuit bridge 9 should be stopped instantaneously,
An instantaneous low voltage setter 22 that sets a low voltage value of the DC voltage value at which the main circuit bridge 9 should stop instantaneously, a voltage value detected by the DC voltage detection circuit 8 and an overvoltage value set by the instantaneous overvoltage setter 21. And the low voltage value set by the instantaneous low voltage setting device 22, and when the voltage value reaches the overvoltage value or the low voltage value, the deviation between the voltage value and the overvoltage value or the low voltage value is amplified. And a deviation amplifier 50 (first and second deviation amplifiers) that outputs the signal as a signal for instantaneously stopping the main circuit bridge 9, and an interlock circuit 16 that receives the signal output by the deviation amplifier 50 and stops the main circuit bridge 9. Is equipped with.

The converter device 56 also includes a hunting determination voltage setter 19 for setting a voltage value for determining the hunting when the voltage detected by the DC voltage detection circuit 8 hunts. , 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 amplifies the deviation between both voltage values when the detected voltage value exceeds the set voltage value. And output as rectangular wave voltage.

The converter device 56 also sets an integrator 51 for integrating the rectangular wave voltage output by the deviation amplifier 50 and a stop level for setting the level of the voltage output by the integrator 51 for stopping the main circuit bridge 9. Comparing the setter 52 with the level set by the stop level setter 52 and the voltage output by the integrator 51, and outputting a signal for stopping the main circuit bridge 9 when the voltage reaches the level. And a device 53 (sixth comparator). The other configuration is the same as the converter device 2 described in the first embodiment.
Since the configuration is the same as that of No. 8, description will be omitted.

The operation of the converter device 56 having such a configuration will be described below. When the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the deviation amplifier 50 amplifies the deviation between the voltage value and the overvoltage value, and the main circuit bridge. 9 is output to the interlock circuit 16 as a signal for instantaneous stop, and the interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) and protects the components including the load capacitor 18.

When the voltage value detected by the DC voltage detection circuit 8 reaches the low voltage value set by the instantaneous low voltage setting unit 22, the deviation amplifier 50 causes the deviation between the low voltage value and the voltage value. Is output to the interlock circuit 16 as a signal for instantaneously stopping the main circuit bridge 9, and the interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to load the inverters 3 to 5 protects components from abnormal operation of overcurrent due to insufficient DC voltage.

The voltage value detected by the DC voltage detection circuit 8 is
When the hunting is continued without reaching the overvoltage value set by the instantaneous overvoltage setting device 21 or the low voltage value set by the instantaneous low voltage setting device 22, the deviation amplifier 50 detects the DC voltage detection circuit 8. The voltage value is compared with the voltage value set by the hunting determination voltage setter 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.

The rectangular wave voltage output from the deviation amplifier 50 is
It is integrated by the integrator 51 and output. The voltage integrated and output by the integrator 51 is compared with the level set by the stop level setting unit 52 by the comparator 53, and when the level is reached, the comparator 53 outputs a signal for stopping the main circuit bridge 9. Is output to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.
Other operations are the same as the operations of converter device 28 described in the first embodiment, and therefore description thereof will be omitted.

As a result, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting unit 21, the converter device 56 sets the low voltage set by the instantaneous low voltage setting unit 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

Sixth Embodiment FIG. 6 is a block diagram showing a configuration of an embodiment of a converter device according to the tenth invention. The converter device 64 includes a counter 59 that counts the rectangular wave voltage output from the deviation amplifier 50, a stop determination value setter 60 that sets a determination value of the count value of the counter 59 that should stop the main circuit bridge 9, Comparing the judgment value set by the stop judgment value setting device 60 with the count value of the counter 59, and outputting a signal for stopping the main circuit bridge 9 when the count value reaches the judgment value (the seventh comparator 7 And a reset circuit 58 for resetting the counter 59 when the rectangular wave voltage output from the deviation amplifier 50 is not input for a predetermined time. Other configurations are the same as the configurations of converter device 56 described in the fifth embodiment, and description thereof will be omitted.

The operation of the converter device 64 having such a configuration will be described below. When the deviation amplifier 50 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, the converter device 64 detects that the detected voltage value exceeds the set voltage value. Is
The deviation between the two voltage values is amplified and output as a rectangular wave.
The counter 59 counts the rectangular wave voltage output by the deviation amplifier 50. On the other hand, the reset circuit 58 includes the deviation amplifier 5
When the rectangular wave output by 0 is not input for a predetermined time, the counter 59 is reset.

The comparator 61 compares the count value of the counter 59 with the judgment value set by the stop judgment value setting device 60, and outputs a signal for stopping the main circuit bridge 9 when the count value reaches the judgment value. It outputs to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.
Other operations are the same as the operations of converter device 56 described in the fifth embodiment, and therefore description thereof will be omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 64 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

Further, since the deviation amplifier 50 shapes the output voltage into a rectangular wave and counts it by the counter 59, if the hunting frequency is the same, the detection time of the hunting operation is the voltage detected by the DC voltage detection circuit 8. When the hunting does not continue regardless of the value and the hunting does not continue for a certain time, the counter 59 is reset. Therefore, even if the hunting occurs temporarily due to the behavior of the loads of the inverters 3 to 5, the capacitance of the capacitor 18 is reduced. It can be distinguished from hunting due to fluctuation.

Embodiment 7. FIG. 7 is a block diagram showing the configuration of the embodiment of the converter device according to the eleventh invention. The converter device 71 includes an up / down counter 66. The up / down counter 66 counts the rectangular wave voltage output from the deviation amplifier 50, and has a clock generator (not shown), and counts down the clock generated by the clock generator.

The converter device 71 also includes a stop determination value setting device 67 for setting a determination value of the count value of the up / down counter 66 for stopping the main circuit bridge 9, and a determination value set by the stop determination value setting device 67. The comparator 68 (eighth comparator) that compares the value with the count value of the up / down counter 66 and outputs a signal to stop the main circuit bridge 9 when the count value reaches the determination value, and the deviation amplifier 50. And a reset circuit 65 that causes the up / down counter 66 to start the countdown of the clock when the rectangular wave voltage output by is not input for a predetermined time. The other configuration is the converter device 56 described in the fifth embodiment.
Since the configuration is the same as that of 1, the description thereof will be omitted.

The operation of the converter device 71 having such a configuration will be described below. When the deviation amplifier 50 compares the voltage value detected by the DC voltage detection circuit 8 with the voltage value set by the hunting determination voltage setter 19, and the detected voltage value exceeds the set voltage value. Is
The deviation between the two voltage values is amplified and output as a rectangular wave.
The up / down counter 66 counts the rectangular wave output by the deviation amplifier 50.

On the other hand, the reset circuit 65 includes the deviation amplifier 5
When the rectangular wave output by 0 is not input for a predetermined time, the up / down counter 66 starts the clock countdown. The up / down counter 66 ends the countdown when it counts down to 0, and when the rectangular wave is input from the deviation amplifier 50 during the countdown, stops the countdown and starts counting from the count value at that time. Start counting.

The comparator 68 is an up / down counter 66.
And the judgment value set by the stop judgment value setting unit 67 are compared, and when the count value reaches the judgment value, a signal for stopping the main circuit bridge 9 is output to the interlock circuit 16. The interlock circuit 16 includes the main circuit bridge 9
The (converter main circuit 10) is stopped to prevent the load capacitor 18 from being damaged due to the temperature rise due to the ripple current. Other operations are similar to those of converter device 56 described in the fifth embodiment,
The description is omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 71 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

Further, since the deviation amplifier 50 shapes the output voltage into a rectangular wave and counts it by the up / down counter 66, if the hunting frequency is the same, the DC voltage detection circuit 8 detects the hunting operation detection time. It becomes almost the same regardless of the applied voltage value. If hunting does not continue for a certain period of time, the up / down counter 66 starts counting down the clock.
Even if the hunting temporarily occurs due to the load behavior of No. 5, it can be distinguished from the hunting due to the capacitance variation of the capacitor 18, and if the rectangular wave is input before the countdown ends, the countdown is stopped. Since counting is started from the count value at that time, even if hunting repeatedly occurs in a short time due to the behavior of the loads of the inverters 3 to 5, it can be distinguished from the hunting due to the capacitance variation of the capacitor 18.

Embodiment 8. FIG. 8 is a block diagram showing a configuration of an embodiment of a converter device according to the twelfth and thirteenth inventions. The converter device 84 includes a hunting determination voltage setter 19 that sets a voltage for determining hunting when the voltage value detected by the DC voltage detection circuit 8 hunts, and a voltage detected by the DC voltage detection circuit 8. The value is compared with the voltage value set by the hunting determination voltage setter 19 and compared with a comparator 72 (a ninth comparator) that outputs an ON signal when the detected voltage value exceeds the set voltage value. A relay 74 (relay contact 75) that is turned on by an ON signal output from the device 72, and a signal generator 73 that generates a predetermined voltage signal when the relay 74 is turned on are provided.

The converter device 84 also compares the voltage value detected by the DC voltage detection circuit 8 with the overvoltage value set by the instantaneous overvoltage setting device 21 and the low voltage value set by the instantaneous low voltage setting device 22 to obtain a voltage value. When the value reaches the overvoltage value or the low voltage value, the main circuit receives the signal output from the comparator 76 (first comparator) that instantaneously stops the main circuit bridge 9 and the signal output from the comparator 76. And an interlock circuit 16 for stopping the bridge 9.

The converter device 84 also includes an integrator 79 for integrating the voltage signal output by the signal generator 73 and a stop level for setting the level of the voltage output by the integrator 79 for stopping the main circuit bridge 9. The interlock circuit compares the level set by the setter 80 and the stop level setter 80 with the voltage output by the integrator 79, and when the voltage reaches the level, the signal for stopping the main circuit bridge 9 is generated. 16 and a comparator 81 (tenth comparator) for outputting to 16. Comparator 72, signal generator 73, relay 7
4 (relay contact 75) and the comparator 76 are isolated comparators 78
Are configured. Other configurations are the same as the configurations of converter device 28 described in the first embodiment, and description thereof will be omitted.

The operation of the converter device 84 having such a configuration will be described below. When the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting unit 21, the comparator 76 outputs a signal for instantaneously stopping the main circuit bridge 9 to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) and protects the components including the load capacitor 18.

When the voltage value detected by the DC voltage detection circuit 8 reaches the low voltage value set by the instantaneous low voltage setting unit 22, the comparator 76 outputs a signal for stopping the main circuit bridge 9 for an instant. It outputs to the interlock circuit 16, and the interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10), and the inverters 3-5 which are loads.
Protect the components from abnormal operation of overcurrent due to lack of DC voltage.

The voltage value detected by the DC voltage detection circuit 8 is
When the overvoltage value set by the instantaneous overvoltage setting device 21 or the low voltage value set by the instantaneous low voltage setting device 22 is not reached and the hunting continues, the comparator 72 detects the DC voltage detection circuit 8. The voltage value is compared with the voltage value set by the hunting determination voltage setter 19, and when the detected voltage value exceeds the set voltage value, an ON signal is output. The relay 74 is turned on by the ON signal output from the comparator 72, and the signal generator 73 outputs a predetermined voltage signal when the relay 74 is turned on.

The voltage signal output from the signal generator 73 is integrated by the integrator 79 and output. The voltage integrated and output by the integrator 79 is compared by the comparator 81 with the level set by the stop level setting unit 80, and when the level is reached, the comparator 81 outputs a signal for stopping the main circuit bridge 9. Is output to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current. Other operations are the same as the operations of converter device 28 described in the first embodiment, and therefore description thereof will be omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 84 sets the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

The comparator 72, the relay 74, and the signal generator 73 can insulate the protection circuit after the integrator 79 from the DC voltage detection circuit 8, and the relay 74 converts the output voltage of the signal generator 73 into a rectangular wave. Since they are molded and integrated by the integrator 79, if 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.

Ninth Embodiment FIG. 9 is a block diagram showing the configuration of the embodiment of the converter device according to the fourteenth invention. The converter device 90 includes a counter 85 that counts the voltage signal output from the signal generator 73 and a counter 8
The stop judgment value setter 86 for setting the judgment value for stopping the main circuit bridge 9 of the count value of 5, and the judgment value set by the stop judgment value setter 86 and the count value of the counter 85 are compared, and A comparator 87 (11th comparator) that outputs a signal for stopping the main circuit bridge 9 when the numerical value reaches the determination value. Other configurations are the same as the configurations of converter device 84 described in the eighth embodiment, and description thereof will be omitted.

The operation of the converter device 84 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 does not reach the overvoltage value set by the instantaneous overvoltage setting device 21 or the low voltage value set by the instantaneous low voltage setting device 22 and the hunting is continued, a comparison is made. Vessel 72
The voltage value detected by the DC voltage detection circuit 8 is compared with the voltage value set by the hunting determination voltage setter 19, and when the detected voltage value exceeds the set voltage value, an ON signal is output. The relay 74 is turned on by the ON signal output from the comparator 72, and the signal generator 73 outputs a predetermined voltage signal when the relay 74 is turned on. Counter 8
5 counts the voltage signal which is the rectangular wave output from the signal generator 73.

The comparator 87 compares the count value of the counter 85 with the judgment value set by the stop judgment value setting device 86, and outputs a signal for stopping the main circuit bridge 9 when the count value reaches the judgment value. It outputs to the interlock circuit 16. The interlock circuit 16 stops the main circuit bridge 9 (converter main circuit 10) to prevent the load capacitor 18 from being damaged due to temperature rise due to ripple current.
Other operations are the same as the operations of converter device 84 described in the eighth embodiment, and therefore description thereof will be omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting unit 21, the converter device 90 sets the low voltage set by the instantaneous low voltage setting unit 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

The comparator 72, the relay 74, and the signal generator 73 can insulate the DC voltage detection circuit 8 from the protection circuit after the counter 85, and the relay 74 shapes the output voltage of the signal generator 73 into a rectangular wave. However, since the counter 85 counts, if 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.

[Embodiment 10] FIG. 10 is a block diagram showing the configuration of the embodiment of the converter device according to the fifteenth invention. The converter device 97 includes an up / down counter 91. The up / down counter 91 is
It counts the voltage signal output from the signal generator 73, and has a clock generator (not shown), and counts down the clock generated by the clock generator.

The converter device 97 also includes a stop determination value setter 93 for setting a determination value of the count value of the up / down counter 91 for stopping the main circuit bridge 9, and a determination set by the stop determination value setter 93. A comparator 94 (a twelfth comparator) that compares the value with the count value of the up / down counter 91 and outputs a signal to stop the main circuit bridge 9 when the count value reaches the determination value, and a signal generator. The up / down counter 91 is provided with a reset circuit 92 for starting the countdown of the clock when the voltage signal output by the terminal 73 is not input for a predetermined time. The other configuration is the converter device 84 described in the eighth embodiment.
Since the configuration is the same as that of 1, the description thereof will be omitted.

The operation of the converter device 97 having such a configuration will be described below. If the voltage value detected by the DC voltage detection circuit 8 does not reach the overvoltage value set by the instantaneous overvoltage setting device 21 or the low voltage value set by the instantaneous low voltage setting device 22 and the hunting is continued, a comparison is made. Vessel 72
The voltage value detected by the DC voltage detection circuit 8 is compared with the voltage value set by the hunting determination voltage setter 19, and when the detected voltage value exceeds the set voltage value, an ON signal is output. The relay 74 is turned on by the ON signal output from the comparator 72, and the signal generator 73 outputs a predetermined voltage signal when the relay 74 is turned on. The up / down counter 91 counts the voltage signal which is a rectangular wave output from the signal generator 73.

On the other hand, the reset circuit 92 includes the signal generator 7
When the rectangular wave output by 3 is not input for a predetermined time, the up / down counter 91 starts the clock countdown. The up / down counter 91 terminates the countdown when it counts down to 0, and when the rectangular wave is input from the signal generator 73 while it is counting down, stops the countdown and returns the count value at that time. Start counting from.

The comparator 94 includes an up / down counter 91.
And the judgment value set by the stop judgment value setter 93 are compared, and when the count value reaches the judgment value, a signal for stopping the main circuit bridge 9 is output to the interlock circuit 16. The interlock circuit 16 includes the main circuit bridge 9
The (converter main circuit 10) is stopped to prevent the load capacitor 18 from being damaged due to the temperature rise due to the ripple current. Other operations are similar to those of converter device 84 described in the eighth embodiment,
The description is omitted.

As a result of the above, when the voltage value detected by the DC voltage detection circuit 8 reaches the overvoltage value set by the instantaneous overvoltage setting device 21, the converter device 97 detects the low voltage set by the instantaneous low voltage setting device 22. When the value is reached, the overvoltage value set by the instantaneous overvoltage setting device 21 or the instantaneous low voltage setting device 22
When the hunting continues without reaching the low voltage value set by, the converter main circuit 10 can be stopped to protect the constituent devices.

Further, the comparator 72, the relay 74 and the signal generator 73 can insulate the protection circuit after the up / down counter 91 from the DC voltage detection circuit 8, and the relay 74 can output the output voltage of the signal generator 73 to a rectangular wave. Since the hunting operation is performed and counted by the up / down counter 91, if 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. When the hunting does not continue for a certain period of time, the up / down counter 91 starts counting down the clock. Therefore, even if the hunting occurs temporarily due to the behavior of the loads of the inverters 3 to 5, the hunting is caused by the capacitance variation of the capacitor 18. When a rectangular wave is input before the countdown ends, the countdown is stopped and counting is started from the count value at that time. Therefore, the behavior of the loads of the inverters 3 to 5 can be distinguished. Therefore, even if the hunting is repeatedly generated in a short time, it can be distinguished from the hunting due to the capacitance variation of the capacitor 18.

[0097]

According to the converter device of the first aspect of the present invention, the converter section supplies the load having the capacitor with the DC power converted from the AC power, and the DC voltage detection circuit outputs the DC voltage output from the converter section. To detect. The instantaneous overvoltage setter sets the overvoltage of the voltage detected by the DC voltage detection circuit that the converter unit should stop for an instant, and the instantaneous low voltage setter sets the overvoltage of the voltage detected by the DC voltage detection circuit of the converter unit. Set the low voltage that should be stopped instantaneously. The first comparator compares the voltage detected by the DC voltage detection circuit with the overvoltage set by the instantaneous overvoltage setting device and the low voltage set by the instantaneous low voltage setting device, and the voltage detected by the DC voltage detection circuit is overvoltage or When it reaches a low voltage, it outputs a signal that causes the converter unit to stop instantaneously . Vibration judgment voltage
The setter vibrates the voltage detected by the DC voltage detection circuit.
Sometimes, the voltage for determining the vibration is set. Second
The comparator detects the set voltage and the DC voltage detection circuit.
The detected voltage exceeds the set voltage.
It outputs the voltage according to the gain. The stop judgment unit
Determine whether to stop the converter section based on the pressure,
Stop the converter section when it is determined that it should be stopped
Output the signal to The interlock circuit has a first ratio
The converter unit is stopped in response to the signal from the comparator or the stop judging unit . Thus, the output and voltage is overvoltage value and
When the hunting continues without reaching the low voltage value, it can be stopped to protect the components.

[0098]

According to the converter device of the second invention,
In the stop determination unit, the integrator integrates the voltage output by the second comparator, and the stop level setting unit sets the level of the voltage output by the integrator at which the converter unit should be stopped.
The third comparator compares the level with the voltage output by the integrator, and outputs a signal for stopping the converter unit when the voltage output by the integrator reaches the level. Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices.

According to the converter device of the third invention,
In the stop determination unit, the waveform shaping circuit shapes the voltage output from the second comparator into a rectangular wave, and the counter counts the rectangular wave. The stop judgment value setter sets a judgment value of the count value at which the converter unit should be stopped, and a fourth comparator compares the judgment value with the count value of the counter, and the count value becomes the judgment value. When it reaches, it outputs a signal to stop the converter unit. Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices. Further, if the hunting frequency is the same, the hunting operation detection time is substantially the same regardless of the voltage value.

According to the converter device of the fourth invention,
The reset circuit resets the counter when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time, so even if hunting occurs temporarily due to the load behavior of the inverter, it can be distinguished from hunting due to fluctuations in the capacitance of the capacitor. can do.

According to the converter device of the fifth invention,
In the stop determination unit, the waveform shaping circuit shapes the voltage output from the second comparator into a rectangular wave, and the up / down counter counts the rectangular wave and counts down the clock generated by the clock generator. The stop determination value setter sets a determination value of the count value of the up / down counter that should stop the converter unit, and a fifth comparator compares the determination value with the count value of the up / down counter, When reaches the judgment value, a signal for stopping the converter is output. The reset circuit causes the up / down counter to start counting down the clock when the rectangular wave output from the waveform shaping circuit is not input for a predetermined time.

As a result, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices. Further, if the hunting frequency is the same, the hunting operation detection time 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 the fluctuation of the capacitance of the capacitor. It can be distinguished from hunting due to capacity fluctuation.

According to the converter device of the sixth invention,
The converter unit supplies the load having the capacitor with the DC power converted from the AC power, and the DC voltage detection circuit
The DC voltage output by the converter is detected. The instantaneous overvoltage setting device sets the overvoltage of the detected DC voltage at which the converter should stop instantaneously, and the instantaneous low voltage setting device
A low voltage of the detected DC voltage at which the converter unit should stop instantaneously is set. The first deviation amplifier compares the voltage detected by the DC voltage detection circuit with the overvoltage set by the instantaneous overvoltage setting device and the low voltage set by the instantaneous low voltage setting device,
When the detected voltage reaches overvoltage or undervoltage,
A deviation between the detected voltage and the overvoltage or the low voltage is amplified and output as a signal for instantaneously stopping the converter unit. The vibration judgment voltage setter detects the DC voltage detection circuit.
The voltage for judging the vibration when the voltage vibrates.
The second deviation amplifier sets the set voltage and DC
The voltage detected by comparing the voltage detected by the voltage detection circuit
When the voltage exceeds the set voltage, the deviation between both voltages is amplified.
Output as rectangular wave voltage. The stop decision unit uses the rectangular wave
Determines whether to stop the converter section based on the voltage
The converter section when it is determined that the
Output the signal to stop. Interlock circuit, the first
1) The converter unit is stopped in response to the signal from the deviation amplifier or the stop judging unit . Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices.

[0105]

According to the converter device of the seventh invention,
In the stop determination unit, the integrator integrates the rectangular wave voltage output by the second deviation amplifier, and the stop level setting unit sets the level of the voltage output by the integrator for stopping the converter unit. The sixth comparator compares the level with the voltage output by the integrator, and outputs a signal for stopping the converter unit when the voltage output by the integrator reaches the level. Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices.

According to the converter device of the eighth invention,
In the stop determination unit, the counter counts the rectangular wave voltage output by the second deviation amplifier, and the stop determination value setter sets the determination value of the count value of the counter that should stop the converter unit. The seventh comparator compares the determination value with the count value of the counter, and outputs a signal to stop the converter unit when the count value reaches the determination value. The reset circuit
When the rectangular wave voltage output from the second deviation amplifier is not input for a predetermined time, the counter is reset. This allows
When the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices. Also, if the hunting frequency is the same, the hunting operation detection time will be approximately the same regardless of the voltage value, and even if the hunting occurs temporarily due to the behavior of the load of the inverter, the capacitance fluctuation of the capacitor will occur. Can be distinguished from hunting by.

According to the converter device of the ninth invention,
In the stop determination unit, the up / down counter counts the rectangular wave voltage output by the second deviation amplifier, and also counts down the clock generated by the clock generator. The stop judgment value setting device sets a judgment value of the count value of the up / down counter that should stop the converter unit, and an eighth comparator compares the judgment value with the count value of the up / down counter to obtain the count value. Outputs a signal for stopping the converter unit when reaches the judgment value. The reset circuit is the second
When the rectangular wave voltage output from the deviation amplifier is not input for a predetermined time, the up / down counter starts the clock countdown.

As a result, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent devices. Further, if the hunting frequency is the same, the hunting operation detection time 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 the fluctuation of the capacitance of the capacitor. It can be distinguished from hunting due to capacity fluctuation.

According to the converter device of the tenth aspect of the present invention, the converter section applies the alternating current to the load having the capacitor.
DC voltage detection circuit that supplies DC power converted from power
Detects the DC voltage output by the converter. Instant
The overvoltage setting device detects the voltage detected by the DC voltage detection circuit.
, The converter section sets an overvoltage that should
The low-voltage setter detects the voltage detected by the DC voltage detection circuit.
Pressure, set a low voltage at which the converter section should stop instantaneously.
It The first comparator detects the voltage detected by the DC voltage detection circuit and
Overvoltage and instantaneous undervoltage set by the instantaneous overvoltage setter
The DC voltage detection circuit compares the low voltage set by the
When the output voltage reaches overvoltage or undervoltage, the converter
Outputs a signal that causes the data unit to stop instantaneously. The vibration judgment voltage setting device sets a voltage for judging the vibration when the voltage detected by the DC voltage detection circuit vibrates, and the ninth comparator judges the voltage detected by the DC voltage detection circuit and the vibration judgment. It compares the voltage set by the voltage setting device and outputs an ON signal when the detected voltage exceeds the set voltage. The relay is turned on by the ON signal, and the signal generator generates a predetermined voltage signal when the relay is turned ON. The stop determination unit determines whether to stop the converter unit based on the voltage signal, and when it determines that the converter unit should stop, outputs a signal to stop the converter unit. The interlock circuit includes a first comparator or a stop determination unit.
The converter unit is stopped in response to the signal from .

As a result, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent 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 is substantially the same regardless of the voltage value.

According to the converter device of the eleventh aspect of the present invention, in the stop determination unit, the integrator integrates the voltage signal output by the signal generator, and the stop level setting unit converts the voltage signal output by the integrator. Set the level at which the department should be stopped. The tenth comparator compares the level with the voltage output by the integrator, and outputs a signal for stopping the converter unit when the voltage output by the integrator reaches the level. Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent 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 is substantially the same regardless of the voltage value.

According to the converter device of the twelfth invention, in the stop determination unit, the counter counts the voltage signal output by the signal generator, and the stop determination value setting unit controls the converter unit of the count value of the counter. Set the judgment value to stop. The eleventh comparator compares the judgment value with the count value of the counter, and when the count value reaches the judgment value, outputs a signal for stopping the converter unit. Thus, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, it is possible to stop and protect the constituent 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 is substantially the same regardless of the voltage value.

According to the converter device of the thirteenth invention, in the stop determination unit, the up / down counter counts the voltage signal output by the signal generator and counts down the clock generated by the clock generator. The stop determination value setter sets a determination value of the count value of the up / down counter that should stop the converter unit, and a twelfth comparator compares the determination value with the count value of the up / down counter to determine the count value. Outputs a signal for stopping the converter unit when reaches the judgment value. The reset circuit causes the up / down counter to start counting down the clock when the voltage signal output from the signal generator is not input for a predetermined time.

As a result, when the output voltage does not reach the overvoltage value and the low voltage value and the hunting continues, the constituent devices can be protected by stopping the hunting. 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 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 the fluctuation of the capacitance of the capacitor. It can be distinguished from hunting due to capacity fluctuation.

[Brief description of 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 showing a configuration of an embodiment of a converter device according to the present invention.

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

FIG. 7 is a block diagram showing 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 showing a configuration example of a conventional converter device.

[Explanation of symbols]

1 Commercial AC power supply, 3-5 inverters, 6 CT, 7
Current detector, 8 DC voltage detection circuit, 10 converter main circuit, 11 reference circuit, 16 interlock circuit,
18 (smoothing) capacitor, 19 Hunting judgment voltage setting device (vibration judgment voltage setting device), 20, 25, 32, 4
6,53,61,68,72,76,81,87,94
Comparator, 21 Instantaneous overvoltage setting device, 22 Instantaneous low voltage setting device, 23, 51, 79 Integrator, 24, 52, 80
Stop level setting device, 29, 36 waveform shaping circuit, 3
0,38,59,85 counter, 31,45,60,
67,86,93 Stop judgment value setting device, 37,58,6
5,92 reset circuit, 44,66,91 up / down counter, 50 deviation amplifier, 73 signal generator,
74 relay, 75 relay contact, 78 insulation comparator.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 7/155

Claims (13)

(57) [Claims] 1. A converter section for supplying direct-current power converted from alternating-current power to a load having a capacitor, a direct-current voltage detection circuit for detecting a direct-current voltage output by the converter section, and a direct-current voltage detection circuit for detecting the direct-current voltage. An instantaneous overvoltage setting device for setting an overvoltage of the voltage at which the converter unit should stop instantaneously, an instantaneous low voltage setting device for setting a low voltage of the voltage for the converter unit to stop instantaneously, and the DC voltage detection circuit Comparing the detected voltage and the overvoltage set by the instantaneous overvoltage setting device and the low voltage set by the instantaneous low voltage setting device, and when the voltage reaches the overvoltage or the low voltage, the converter unit Detected by the first comparator that outputs a signal to stop instantaneously and the DC voltage detection circuit
When the generated voltage vibrates, the voltage for judging the vibration
Vibration judgment voltage setter for setting pressure and DC voltage detection
The voltage detected by the circuit and the vibration judgment voltage setting device
The detected voltage is compared with the set voltage.
A second comparator that outputs a voltage corresponding to the amount that exceeds the pressure;
2 The converter is stopped based on the voltage output from the comparator.
When it is judged that it should be stopped and when it is judged that it should be stopped
To output a signal to stop the converter section
A determination unit receives the first comparator or signal the stop determination unit is output, the converter device characterized in that it comprises an interlock circuit for stopping the converter unit. 2. The stop determination unit is configured to output the voltage output from the second comparator.
The integrator that integrates the pressure and the voltage output by the integrator
Stop level that sets the level at which the inverter section should be stopped.
And the level set by the stop level setter
The voltage output from the integrator is compared, and the voltage is
Signal to stop the converter section when
The converter device according to claim 1 , further comprising a third comparator that outputs 3. The stop determination unit, a waveform shaping circuit for shaping the voltage output from the second comparator into a rectangular wave, and the waveform shaping circuit.
A counter for counting the rectangular wave output by the
Set the judgment value of the count value that should stop the converter
Stop judgment value setting device and the stop judgment value setting device
The determined value is compared with the counted value of the counter, and the counted value is
Stops the converter section when reaches the judgment value
Converter device according to claim 1, further comprising a fourth comparator for outputting a signal to. 4. The rectangular wave output from the waveform shaping circuit is at a predetermined time.
Reset for resetting the counter when there is no input
The converter device according to claim 3, further comprising a switching circuit . 5. The stop determination unit is configured to output the voltage output from the second comparator.
Waveform shaping circuit for shaping pressure into rectangular wave and clock generator
The square wave output from the waveform shaping circuit is counted and
Count down the clock generated by the lock generator
Up / down counter and the up / down counter
Set the judgment value of the count value that should stop the converter
Stop judgment value setting device and the stop judgment value setting device
Compare the judgment value with the count value of the up / down counter
When the count value reaches the judgment value, the converter
A fifth comparator for outputting a signal for stopping the data section;
The rectangular wave output from the waveform shaping circuit is not input for the specified time
Sometimes, the clock of the clock is
Converter device according to claim 1, further comprising a reset circuit for starting the countdown. 6. Is AC power applied to a load having a capacitor?
And a converter unit for supplying DC power converted from the
DC voltage detection circuit that detects the DC voltage output from the barter section
And the voltage of the voltage detected by the DC voltage detection circuit.
Instantaneous overvoltage that sets the overvoltage at which the burner unit should stop instantaneously
The setter and the converter section for the voltage will stop instantaneously.
A low-voltage setting device that sets an appropriate low voltage, and
Set the voltage detected by the pressure detection circuit and the instantaneous overvoltage setting device.
Constant overvoltage and the low voltage set by the instantaneous low voltage setting device.
Compared with the pressure, the voltage becomes the overvoltage or the undervoltage.
When reached, the voltage and the overvoltage or the low voltage
Amplifies the deviation of and stops the converter section instantaneously
A first deviation amplifier for outputting as a signal, and the DC voltage detector
When the voltage detected by the output circuit vibrates, the vibration is detected.
The vibration determination voltage setting device that sets the voltage for
The voltage detected by the DC voltage detection circuit and the vibration judgment voltage setting
The voltage detected by the detector is compared with the voltage set by
When the specified voltage is exceeded, the deviation between both voltages is amplified.
A second deviation amplifier that outputs a rectangular wave voltage, and a second deviation
The converter is stopped based on the rectangular wave voltage output from the amplifier.
It was decided whether to stop it, and it was decided that it should be stopped
Stop, which outputs a signal to stop the converter section.
A stop determination portion, or the stop determination unit first deviation amplifier outputs
Signal to stop the converter section
And a lock circuit . 7. The stop judgment section outputs the second deviation amplifier.
And an integrator that integrates the rectangular wave voltage
Set the voltage level at which the converter section should be stopped.
Stop level setting device and the stop level setting device
The level is compared with the voltage output by the integrator, and the voltage
Stops the converter section when reaches the level
7. A sixth comparator which outputs a signal for
On-board converter device. 8. The stop judgment unit outputs the second deviation amplifier.
And a counter for counting the rectangular wave voltage
Set the judgment value of the value that should stop the converter
The stop judgment value setter and the judgment set by the stop judgment value setter.
The constant value and the count value of the counter are compared, and the count value is
When the judgment value is reached, stop the converter section.
The 7th comparator that outputs the signal
If the rectangular wave voltage is not input for a predetermined time,
Claim and a reset circuit for resetting the counter 6
The converter device described. 9. The stop determination unit counts the rectangular wave voltage output from the second deviation amplifier , and has a clock generator,
Count down the clock generated by the clock generator
Up / down counter and the up / down counter
Of the judgment value of the
Set the stop judgment value setting device and the stop judgment value setting device.
The determined judgment value and the count value of the up / down counter
Compare, when the count value reaches the judgment value, the
An eighth comparator for outputting a signal for stopping the inverter section,
The rectangular wave voltage output from the second deviation amplifier is input for a predetermined time.
The up / down counter,
7. The converter device according to claim 6 , further comprising a reset circuit for starting a countdown of the clock. 10. AC power is applied to a load having a capacitor.
A converter unit for supplying DC power converted from
DC voltage detection to detect the DC voltage output from the inverter
Of the circuit and the voltage detected by the DC voltage detection circuit.
Instantaneous overvoltage that sets the overvoltage at which the inverter section should stop instantaneously
Instantaneous stop of the pressure setting device and the converter of the voltage
An instantaneous low voltage setting device for setting a low voltage to be
Wherein the voltage detection voltage circuit detects instantaneous overvoltage setter is
The set overvoltage and the low voltage set by the instantaneous low voltage setting device.
The voltage is compared with the voltage, and the voltage is the overvoltage or the undervoltage
Is reached, the signal to stop the converter section instantly is reached.
Signal output from the first comparator and the DC voltage detection circuit.
When the generated voltage vibrates, it is for judging the vibration.
The vibration judgment voltage setter that sets the voltage and the DC voltage detector
The voltage detected by the output circuit and the vibration judgment voltage setting device set
The detected voltage is compared with the voltage
Ninth comparator that outputs an ON signal when the voltage is exceeded
And a relay that is turned on by the ON signal output from the ninth comparator.
And a specified voltage signal when the relay is on.
And a signal generator that generates
Determine whether to stop the converter unit based on the voltage signal
If you decide to turn it off and stop it,
A stop determination unit that outputs a signal to stop
In response to the signal output from the comparator or the stop judgment unit,
And an interlock circuit for stopping the inverter unit
A converter device characterized by the above . 11. The stop determination unit is output by a signal generator.
The integrator that integrates the voltage signal and the voltage output by the integrator
, Which sets the level at which the converter section should be stopped.
Stop level setter and the level set by the stop level setter.
And the voltage output by the integrator is compared to
When the above level is reached, stop the converter section
11. The converter device according to claim 10 , further comprising: a tenth comparator that outputs a signal that outputs a signal . 12. The stop determination section is output by a signal generator.
Counter for counting voltage signals and count value of the counter
, Which sets the judgment value that should stop the converter
Stop judgment value setter and judgment set by the stop judgment value setter
The value is compared with the count value of the counter, and the count value is
When the judgment value is reached, stop the converter section
The converter device according to claim 10 , further comprising an eleventh comparator that outputs a signal . 13. The stop determination unit counts the voltage signal output from the signal generator, and has a clock generator,
Count down the clock generated by the lock generator
Up / down counter and the up / down counter
Set the judgment value of the count value that should stop the converter
Stop judgment value setting device and the stop judgment value setting device
Compare the judgment value with the count value of the up / down counter
When the count value reaches the judgment value, the converter
A twelfth comparator that outputs a signal for stopping the data unit,
The voltage signal output from the signal generator is not input for the specified time.
The clock of the up / down counter
The converter device according to claim 10 , further comprising a reset circuit that starts a countdown .