JPH025273B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thyristor operation monitoring device in a high-voltage thyristor AC/DC converter or the like configured by a plurality of thyristors connected in series.

[Prior Art] Conventionally, in this type of thyristor operation monitoring device, for example, in the above-mentioned high-voltage thyristor AC/DC converter, as shown in FIG. 1, a large number of thyristors 1a, 1b,
..., 1n, light emitting diode 2
a, 2b,..., 2n and resistors 3a, 3b,..., 3n
When the thyristor elements are connected in series and connected in parallel, and each thyristor element is operating normally, and the voltage shared by each thyristor element is applied to each thyristor element during each blocking period, the applied voltage A corresponding current flows through each light emitting diode, causing it to emit light. The light emitted by each light emitting diode during healthy operation of each of these thyristor elements is expressed by each light emitting diode 2a, 2b, ..., 2n.
A large number of light guides 4a each combined with
4b,..., 4n, the monitoring device 5 placed at ground potential receives the light, and each thyristor element 1a, 1b,
..., 1n, each light emitting diode 2a,
It was possible to monitor the light emission states of the lights 2b, . . . , 2n by comparing them with the monitoring device 5.

[Problems to be Solved by the Invention] To this end, in conventional thyristor operation monitoring devices, a large number of signal transmission devices, such as expensive light guides and light emitting diodes, are used for each circuit component, for example, for each thyristor element. Not only does the equipment cost of the signal transmission system increase as the number of circuit components increases, but also the configuration of the monitoring device becomes complicated.

In addition, in the above example, current flows through the light emitting diode throughout the blocking period of the thyristor and it emits light, so increasing the light emitting output to clearly transmit information will shorten the life of the light emitting diode. Conversely, if the light emitting output of the light emitting diode is suppressed in consideration of its lifespan, it becomes necessary to increase the light receiving sensitivity, which poses a problem in the noise resistance of the monitoring device 5.

Therefore, the present invention eliminates the drawbacks of the conventional device described above, significantly reduces the number of signal transmission systems required, and simplifies the configuration of the operation monitoring device, thereby stably and reliably operating the thyristor over a long period of time at low cost. An object of the present invention is to provide a device for monitoring the operation of a thyristor.

[Means for Solving the Problems] In order to solve these problems, the present invention has the following features:
A plurality of thyristors connected in series, a plurality of voltage detection resistors each having one end connected to the anode and cathode of each of the thyristors, each having two input terminals, and each input terminal has a a plurality of comparators connected to the other ends of voltage detection resistors connected to the anode and cathode of each of the thyristors; a pulse generator generating continuous pulse signals; each having two input ends; a plurality of AND gates, each of which has one input terminal to which the output of each of the comparators is guided, and the other input terminal to which a continuous pulse signal generated from the pulse generator is sequentially guided; one OR gate to which the outputs of the plurality of AND gates are guided, a pulse amplifier that amplifies the output pulse of this OR gate, one light emitting diode that is pulse driven by this pulse amplifier, and one light emitting diode that is pulse driven by this pulse amplifier; By monitoring one light guide that transmits light emission and the light emission state of the light emitting diode transmitted by this light guide,
Monitoring the operating states of the plurality of thyristors 1
The invention is characterized by comprising a monitoring device.

〔Example〕

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

First, an example of the configuration when the present invention is applied to the above-mentioned high voltage thyristor AC/DC converter is shown in FIG.
Figures 3 and 4 show the operating waveforms of each part of the thyristor, which is a circuit component, during normal operation and during failure.
Each is shown in the figure.

In the configuration example shown in Fig. 2, n thyristors 1a, 1b, ..., 1n of the thyristors of the same arm in the high voltage converter are set as one group, and one set of monitoring devices is attached to each group. , n thyristors can be commonly monitored through one light emitting diode and one light guide. That is, each thyristor 1a, 1b,..., 1n is provided with a voltage detection resistor 6.
thyristors 1a, 1b, 6n are connected to each other, and each thyristor 1a, 1b,
The anode and cathode potentials of the thyristors 1a, 1b, . . . , 1n are introduced to the + and - input terminals of the n comparators 7a, 7b, . When divided, each comparator 7
A high logic level signal of a comparison output is obtained from a, 7b, . . . , 7n. The comparison output signals of each comparator 7a, 7b,..., 7n are led to one input terminal of each AND gate 8a, 8b,..., 8n, and the sequential pulse signals from the shift register 11 are sent to the AND gates. 8
It is supplied to the other input terminals of a, 8b, . . . , 8n. Under the control of the transmission command calculator 12, the shift register sequentially outputs pulse signals in accordance with the clock signal (having a cycle sufficiently shorter than the thyristor operation cycle) from the transmission command calculator 12. Since the output pulse signal is shifted, each AND gate 8a, 8b,
..., 8n are sequentially closed, and each comparator 7a,
The comparison output signals from 7b, .
According to the step of the output pulse signal of the shift register 11, the light-emitting diode 2 performs each comparison of each comparator 7a, 7b,..., 7n representing the healthy operation of each thyristor 1a, 1b,..., 1n. It emits light sequentially according to the output pulse. The sequential light emission is electrically insulated and safely transmitted via the light guide 4 to a monitoring device 5 placed at ground potential, and the number of light emission pulses is counted, for example, to each thyristor 1a, 1b, . . . . 1n for healthy operation.

FIG. 3 shows the operation waveforms of each part of the thyristor operation monitoring device according to the present invention having the above-described configuration when each thyristor is operating normally. In other words, when all the thyristors 1a, 1b,..., 1n are operating normally, each comparator 7a, 7b,..., 7n
Comparison output signals of logical level "1" shown in waveforms 7a, 7b, . . . , 7n are supplied to each AND gate 8a, 8b, . . . , 8n. In such a state, waveform 1 from the transmission command calculator 12
Shift register 1 in response to the command pulse shown in 2.
1 advances, and each AND gate 8a, 8b,...,8
Shift pulses as shown in waveforms 8a, 8b,..., 8n are sequentially applied to n, and the AND gates 8a, 8b,..., 8n are sequentially closed, and the OR gate 9 produces a shift pulse as shown in waveform 10. The motion detection output signal converted into a series of n consecutive pulses causes the light emitting diode 2 to emit light via the pulse amplifier 10.

In contrast to the operating waveforms during normal operation, for example, the operating waveforms of each part when the thyristor 1b fails and does not share its forward voltage and therefore no comparison output signal is obtained from the comparator 7b are shown below. It is shown in FIG. 4 according to FIG. 3. That is, since only the comparison output of the comparator 7b is at the logic level "0" as shown in waveform 7b, the operation detection output signal finally applied from the pulse amplifier 10 to the light emitting diode 2 is as shown in waveform 10. Thus, there are (n-1) pulse train signals in which the second pulse corresponding to the thyristor 1b is deleted.
Therefore, by counting the light emitted from the light emitting diodes 2 based on the operation detection output signal in the monitoring device 5, it is possible to grasp the number of healthy elements or the number of failed elements and monitor the operating state of each circuit component. , Furthermore, from the position of the missing pulse,
It is also possible to determine which circuit component has failed.

In the above configuration example, the forward voltage of the thyristor elements 1a, 1b, ..., 1n is monitored, but if the polarity of the comparators 7a, 7b, ..., 7n is changed, the reverse voltage of each thyristor element can be monitored. Furthermore, it is also possible to identify and monitor whether each thyristor element has shared the voltage, regardless of the forward or reverse voltage polarity.

Further, the transmission command calculator 12 can also supply a control signal to the shift register 11 using a signal supplied from a control device placed at a ground potential.

[Effects of the Invention] As is clear from the above description, according to the present invention, for example, n thyristors in a high-voltage orthogonal conversion device can be commonly used by simply providing a single set of expensive light guides, light receiving and emitting elements, etc. Therefore, the configuration of the entire monitoring device can be simplified. In addition, for example, since the current flowing through the light emitting diode is pulsed, the light emitting diode can be used for a long time, and at the same time, the instantaneous amount of light emitted can be increased to clarify the transmission of information, and It is also possible to increase the noise margin of the light receiving circuit by eliminating the need to increase the light receiving sensitivity of the light receiving circuit, thereby improving the noise resistance of the monitoring device.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional thyristor operation monitoring device, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a waveform diagram showing operation waveforms of each part during normal operation. FIG. 4 is a waveform diagram showing the operation waveforms of each part at the time of failure. 1a, 1b,..., 1n...thyristor, 2, 2
a, 2b,..., 2n... Light emitting diode, 3a,
3b,..., 3n...Resistance, 4, 4a, 4b,...,
4n...Light guide, 5...Monitoring device, 6a,
6b,..., 6n...Resistance, 7a, 7b,..., 7n
... Comparator, 8a, 8b, ..., 8n ... AND gate, 9 ... OR gate, 10 ... Pulse amplifier, 11 ... Shift register, 12 ... Transmission command calculator.

Claims (1)

[Claims] 1. A plurality of thyristors 1a, 1 connected in series.
b,..., 1n, and a plurality of voltage detection resistors 6a, 6b, 6c,..., 6n, 6n+1 each having two input terminals, one end of which is connected to the anode and cathode of each of the thyristors, respectively. , a plurality of comparators 7a, 7b, . . . , 7n, each of which has its input terminal connected to the other end of a voltage detection resistor connected to the anode and cathode of each of the thyristors, respectively, and a continuous pulse signal. Generating pulse generator 1
1 and each has two input terminals, one input terminal receives the output of each of the comparators, and the other input terminal receives a continuous pulse signal generated from the pulse generator, respectively. a plurality of AND gates 8a, 8b,..., 8n from which the outputs of the plurality of AND gates are sequentially guided; and 1 from which the outputs of the plurality of AND gates are guided.
or gate 9; a pulse amplifier 10 for amplifying the output pulse of the or gate; and a pulse amplifier 10 driven by the pulse amplifier.
light emitting diodes 2; one light guide 4 that transmits the light emitted from the light emitting diodes; and by monitoring the light emitting state of the light emitting diodes transmitted by the light guide, A thyristor operation monitoring device comprising: one monitoring device 5 for monitoring an operating state.