JPS6236460B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a multi-phase parallel chopper circuit that is designed to operate in the same manner as before the failure when a multi-phase chopper circuit fails in parallel operation of chopper circuits that require high reliability. The present invention relates to a control circuit.

Although the present invention can be applied to a general polyphase parallel chopper, for convenience of explanation, a two-phase chopper will be described.

Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 is the input power supply DC voltage positive side, 2 is the input power supply DC voltage reference side, 3a, 3b
4 is a fuse, 4 is a main chopper main circuit, 5 is an auxiliary chopper main circuit, 6 is a chopping operation abnormality detector, 7 is a short circuit thyristor, 8 is a short circuit current suppressing resistor, 9 is a control circuit, and 10 is a load.

Next, the operation will be explained. In the conventional circuit, normal operation is a circuit formed by a loop connecting the fuse 3a, the main chopper main circuit 4, the chopping abnormality detector 6, and the load 10. At this time, the auxiliary chopper main circuit 5 is not operating.

Now, for some reason, the main chopper main circuit 4 is
If arc extinguishing fails and a failure occurs, the chopping abnormality detector 6 transmits the occurrence of the abnormality to the control circuit 9. The control circuit 9 immediately sends an ignition signal to the gate of the short circuit thyristor 7 to cause a short circuit current to flow through the short circuit current suppressing resistor 8. This short circuit current blows the fuse 3a, which causes the main chopper main circuit 4
After that, a signal is sent from the control circuit 9 to the gate of the auxiliary chopper main circuit 5, and a circuit is formed with a loop connecting the fuse 3b, the auxiliary chopper main circuit 5, the chopping abnormality detector 6, the load 10, and then the main chopper If the main circuit 4 fails due to ignition failure, the operation is almost the same as when the extinguishing failure occurs, but even if a signal is sent to the gate of the short circuit thyristor 7, the fuse 3a will not blow due to the ignition failure. The only difference is in one point.

Since the conventional multi-phase chopper device is constructed as described above, the auxiliary chopper main circuit 5 does not work at all in the normal state and is driven only when the main chopper main circuit 4 is abnormal, so that it can be activated in the event of an abnormality. The reliability was low. In addition, in the control circuit 9, it was necessary to take advantage of the gate of the auxiliary chopper main circuit 5 with sufficient margin in case of a failure (failure to extinguish the arc) in the main chopper main circuit 4, otherwise the fuse 3a would fail.
If a signal enters the gate of the auxiliary chopper main circuit 5 before the fuse 3a is blown by the short-circuit current flowing through the main chopper main circuit 4, the chopping abnormality detector 6, the short-circuit thyristor 7, and the short-circuit current suppression resistor 8, the auxiliary chopper main circuit 5 is activated. The fuse 3b will also be blown. Another disadvantage is that the control circuit 9 is complicated in order to prevent the output signal from the main chopper main circuit 4 from being applied when ignition fails.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by completely updating the control circuit, the two chopper main circuits of the main circuit are always in a driving state, and in the event of a failure, multiple chopper main circuits can be activated at the same time. The control circuit is simplified so that no problems occur even when the main circuit is driven, and the switching time is shortened.Also, even if either of the main circuits of the chopper fails (failed to extinguish or fail to ignite), the faulty main circuit is disconnected. The purpose is to provide a chopper device that can perform

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. In FIG. 2, the configurations 14 and 15 are the same as the chopper main circuits 4 and 5 in FIG. 1, but 14 is the first chopper main circuit, and 15 is the second chopper main circuit. It is called Chiyotsupa main circuit. 11a is the first chiyotsupa NFB, 11b is the second
Chopper NFB, 6a is the first chopply hopping abnormality detector, 6b is the second chopply hopping abnormality detector, 7a is the first chopply short-circuit thyristor, 8a is also the short-circuit current suppression resistor, and 7b is the second chopply hopping abnormality detector.
8b is a short-circuit current suppressing resistor, 12 is a control circuit, 13a and 13b are butt diodes, and 16 is a current detector.
In FIG. 3, 18a is a first chopper hopping abnormality detection circuit, 18b is a second chopper hopping abnormality detection circuit, 19a is a first chopper short-circuit thyristor, 7a is a gate signal generation circuit, and 19b is a second chopper hopping abnormality detection circuit. A gate signal generation circuit for the short-circuit thyristor 7b, 20 is an oscillator, 21 and 22 are integral functions +
A circuit with a comparator function, 23 is a switching circuit,
24 is a comparator circuit, 25 is a first chopper firing pulse generation circuit, 26 is a differentiation circuit, and 27 is a first
28 is a second chopper ignition pulse generation circuit, 29 is a second chopper quenching pulse generation circuit, 30 is a low level addition + switching circuit, 31 is a circuit in case of failure of the first and second chopper An ignition pulse generation circuit, 32 an extinguishing pulse generation circuit when the first and second choppers fail, 34 a current reference circuit, 3
5 is a computing unit. In FIG. 4, 36 is a signal from the oscillator 20 to the circuit 21, 37 is a signal from the oscillator 20 to the circuit 22, 38 is the output of the circuit 21, and 3
9 is the output of the circuit 22, 40 is the input of the first chopper firing pulse generator 25, 41 is the input of the second chopper firing pulse generator 28, 42 is the input of the first chopper firing pulse generator 27, 43 is the input of the second chopper arc extinguishing pulse generator 29, 44 is the output of the low level addition + switching circuit 30, and 45 is the first and second
46 is the input of the ignition pulse generation circuit 31 when the chopper is out of order, 46 is the input of the extinguishing pulse generation circuit 32 when the first and second choppers are out of order, and 47 is the output of the arithmetic circuit 35.The operation will be explained with reference to FIG. , an example of the control circuit 12 is shown in FIG. 3, and an example of the signals therein is shown in FIG.

The second part explains the operation using Figures 2 to 4.
In the figure, in a normal state, the first chopper main circuit 1
4 and the second chopper main circuit 15 are alternately turned on and off. This will be explained using FIGS. 3 and 4. In FIG. 3, from the oscillator 20,
Integral comparator circuit 21, 22, phase 180
Signals shown as waveforms 36 and 37 in FIG. 4 shifted by .degree. are input. As a result, the integral comparator circuit 21,2
The outputs of switching circuit 2 have waveforms 38 and 39 in FIG. 4, respectively.In a normal state, the outputs of switching circuit 2 in FIG.
3 is opened, and the gate of the low level addition + switching circuit 30 is closed. Therefore, by comparing the current feedback 16 and the current reference 34,
The comparator 24 compares the reference waveform 47 and the signals 38 and 39 in FIG. Waveform 4
0, the ignition pulse signal of the second chopper ignition pulse generation circuit 28 becomes waveform 41 in FIG. 4, and at the same time, the signals of waveforms 42 and 43 in FIG. Add.

Therefore, under normal conditions, 40 and 4 in FIG.
1, and the waveforms 42 and 43 are signals with a phase shift of 180 degrees, and this drives the main circuit in Fig. 2, so the first and second chopper main circuits 1
4 and 15 will alternately repeat firing and extinguishing.

Now, assuming that the first chopper main circuit 14 has failed for some reason, the chopping abnormality detector 6a detects the abnormality, the chopping abnormality detection circuit 18a shown in FIG.
closes the gate of the switching circuit 23 and opens the gate of the low-level adder+switching circuit 30, and at the same time sends a signal to the gate signal generation circuit 19a of the short-circuit thyristor 7a. As a result, the short-circuit thyristor 7a conducts, and the NFB 11a trips due to the short-circuit current. On the other hand, the switching circuit 23 of the control circuit 12 closes the gate, and the low-level adder + switching circuit 30 generates the waveforms 38 and 39 in FIG. Low level addition is performed, and a waveform 44 in FIG. 4 appears at the output of 30. The following is similar to the normal condition, waveforms 47 and 44 of FIG. 4 are compared at 24, and this condition is shown in waveform 45. Further, a signal having a waveform 46 in FIG. 4 which has passed through the differentiating circuit 26 is simultaneously applied as an extinction pulse to the first and second chopper main circuits.

The main circuit trips the NFB 11 regardless of whether it fails to start or extinguish, so the faulty main circuit is disconnected, so even if a signal is given to the gate, no problem will occur.

Furthermore, even if the control circuit sends a signal to the gate of the healthy chopper main circuit during the trip operation of the NFB 11 by the diode 13 in Fig. 2, a secondary failure will not be induced and power will be output at twice the frequency of the normal state. death,
This means that power is supplied to the load at the same frequency both in normal and abnormal states.

In the above embodiment, a two-phase parallel chopper main circuit is described, but the present invention is generally applied to a multi-phase parallel chopper main circuit. Also, although the main circuit is disconnected using NFB, it is also possible to use a high-speed tripping device such as a fuse.

As described above, according to the present invention, the multi-phase chopper main circuit is driven even in the normal state, so in the unlikely event that a phase in which a problem occurs can be covered by the remaining phase chopper main circuits. Yes, it is highly reliable.
Furthermore, since failure detection, switching, etc. are handled using electrical signals, switching time can be shortened. Furthermore, after a failure, the abnormal main circuit is completely disconnected by NFB or the like, so even if a signal enters the thyristor gate of the failed chopper main circuit, there is no problem, and the control circuit is also simplified.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional two-phase chopper device, FIG. 2 is a circuit diagram showing an embodiment of the present invention,
FIG. 3 is a block diagram showing details of a control circuit according to an embodiment of the present invention, and FIG. 4 is a waveform diagram showing waveforms of various parts of the block shown in FIG. 4... Main chopper main circuit, 5... Auxiliary chopper main circuit, 6... Chopping abnormality detector, 7... Short circuit thyristor, 8... Short circuit current suppression resistor, 9... Control circuit, 10... Load, 12... Control circuit of the present invention, 13...
Diode, 14...First chopper main circuit, 15...
2nd chopper main circuit, 16... current detector, 18...
Chopping abnormality detection circuit, 19... Short circuit thyristor gate pulse generation circuit, 20... Oscillator, 21,
22... Integral + comparator circuit, 23... Switching circuit, 24... Comparator, 25... First chopper firing pulse, 26... Differential circuit, 27... First chopper extinguishing pulse circuit, 28... Second chopper firing pulse, 29 ...Second chopper arc extinguishing pulse circuit, 30...
Low level adder + switching circuit, 31... First and second chopper main circuit ignition pulse circuit in case of failure, 32...
1st and 2nd chopper main circuit arc extinguishing pulse circuit at the time of failure, 34...Current reference, 35...Arithmetic circuit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a device that controls a multi-phase parallel chopper main circuit, a plurality of tripping devices are inserted between each chopper main circuit and the input power source and are activated by an increase in passing current, and this tripping device and each of the chopper main circuits mentioned above are connected to each other. a plurality of first circuits each inserted between the circuit and the circuit, each receiving an input signal and causing a short-circuit current to flow to the corresponding tripping device; a plurality of second circuits each generating a signal having a phase shift by a predetermined angle; The firing signals and extinction signals of the corresponding chopper main circuits are derived from the signals generated by the plurality of second circuits, and the signals generated by the plurality of third circuits and the plurality of second circuits are derived. A fourth circuit that generates the combined signal; a fifth circuit that derives the firing signal and extinguishing signal for each chopper main circuit from the output of this fourth circuit; and detects an abnormality in any chopper main circuit. 6th
a seventh circuit that supplies an input signal to the first circuit corresponding to the arbitrary chopper main circuit by the operation of this sixth circuit; A multiphase parallel chopper control device comprising an eighth circuit that cuts off the operation and supplies the firing signal and extinction signal generated by the fifth circuit to each chopper main circuit.