JPS58151824A - Monitor for ac/dc converter controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monitoring device for a control device for an AC/DC converter in a DC power transmission system.

BACKGROUND ART Conventionally, a gate control element consisting of a plurality of thyristors or the like has been applied to a control device for an AC/DC converter in a DC power transmission system. The timing and pulse width of the gate element control pulse are interconnected with the gate pulses of other gate elements and operate in a predetermined order, so the temporal accuracy is severe and the quality is degraded by the equipment in the power transmission system. destruction of
was also a contributing factor. In recent years, as the number of systems that configure DC power transmission systems by multiplexing AC/DC converters has increased, the importance of controlling the accuracy of the gate pulses mentioned above has rapidly come into question. There is no device that comprehensively monitors the output of the device, including its operational accuracy.

Figure 1 is a circuit of the main part that simply shows the AC/DC converter section of a well-known conventional DC power transmission system. 1 is the main transformer on the power transmission side, and 2 is the circuit that controls the DC transmission current by gate control. It is a thyristor.

Normally, the control device of an AC/DC converter controls six thyristors U, V, W, X, Y, and Z to set DC power, DC current, DC voltage, commutation margin angle of thyristors, etc. to desired values. It is configured to deliver an ignition pulse for gate control.

Therefore, the thyristor tr output from one control device,
v, w and X, Y.

The six types of ignition pulses to 2 are collectively referred to as ``ignition pulse group'' here.

FIG. 2 shows a conventional example in which the above-mentioned control devices are multiplexed, 3-1.3-2.3-3 is an example in which a plurality of the above-mentioned control devices are configured in parallel, and 4-1. 4-2.4-
3 is the ignition pulse group of the plurality of control devices 6-1, 3-2, 5-3, or 5 is the ignition pulse group 4 of the plurality of control devices 6-1, 3-2, 5-3.
-1, 4-2, 4-6 selection devices; 6 is a firing pulse group selected by the selection device; 16 is an AC/DC converter controlled by the firing pulse group 6;

In conventional AC/DC converter control devices configured in this way, a monitoring method has been established that includes the timing of gate control pulse generation and its subtle temporal accuracy, such as pulse generation phase shift angle and pulse width. Specifically, the internal and external electrical failure factors that the gate pulse generation circuit is subject to due to the lack of proper protection include changes in the characteristics of semiconductor elements and capacitors due to changes in the temperature environment, deterioration over time, and external noise to the circuit elements. Circuit reliability countermeasures are taken to prevent the inherent causes of accidents such as phase-to-phase short circuits and voltage pulsations, which are major problems for gate control devices of AC/DC converters, such as electrical shocks caused by electrical shocks, and even lower reliability of the entire circuit. Needless to say, there was an urgent need to establish a circuit monitoring system.

The present invention has been made to eliminate the above-mentioned drawbacks, and when a plurality of AC/DC converter control devices are multiplexed, the pulse signals that are the output signals of the control devices, that is, the gate pulses for controlling the thyristors, can be mutually transmitted. Monitoring of an AC/DC converter control device that monitors the waveform of the output signal of the control device, including its temporal accuracy, by a device completely independent of the gate control device, by comparing several time elements. The purpose is to provide equipment.

Hereinafter, one embodiment of the present invention will be specifically explained with reference to FIGS. 3 and 4.

That is, FIG. 43 and @4 show one embodiment of the present invention, and FIG. 3 shows a defect determination circuit for determining whether a control device output pulse is defective. KH2 for ease of understanding
Conventional control device for gate control shown in the figure 5-1.3-
The ignition pulse to the thyristor U in No. 2 will be explained as an example.

First, 7-1 is a mismatch detection circuit that outputs logic @1@1jt to its output when the input logic, that is, the output signals U, , U of the control devices 3-1 and 6-2 in FIG. (exclusive OR circuit) and its output side Klf
A mismatch width detection circuit 8 is connected which outputs a predetermined pulse when the pulse width of the output signal of the mismatch detection circuit 7-1 exceeds a certain value. Then, a counter circuit 9 that counts the output pulses of the mismatch width detection circuit 8 determines a specific condition, that is, the output signal 15 of the timer 10 is set to logic @11.
Counting is possible only when Therefore, timer 10
The counter circuit 9 is always reset to the initial state when the output signal 15 of the gate control device 3-1. Only when the pulses are generated continuously, the timer circuit 10YIJ) is triggered and the counter 9tt operating condition is set.Then, when the counter 9 counts a certain value and generates an output pulse, the number of pulses is memorized. A memory circuit 11 is connected to the output of the counter 9 to monitor the two ignition pulses Ul when the output signal 12 of the memory circuit 11 switches to logic 1.

It is determined that either one of U and U has malfunctioned. Of course, mismatch width detection circuit 8, counter 9, timer 1
The constant setting in each circuit of 0 is determined by the accuracy of control of the monitored device. Next, an example will be described in which the present invention is applied to the example of the defect determination circuit Y shown in FIG. 2, which was explained in FIG. ! ! In Figure 4 ◆1. 2. +5 is @2 respectively
Thyristors U, , U, of the control device 3-1.5-2.3-3+ in the figure.

is the ignition pulse of U. The mismatch detection circuits 7-2 and 7-3 in FIG. 4 are respectively the same as the mismatch detection circuit 7-1 shown in FIG.
-2 and 14-3 are the same as the circuit configuration in the defective determination circuit 14-1 in Figure @3. Therefore, in the defect determination circuit 14-1 shown in Figure @4, the ignition pulse φ1. or φ2 is defective, and the defect determination circuit 14-3 determines whether the ignition pulse generator 1. or 3 is defective. Here, if the defective determination circuit 14-1.
Or, if it is determined that both circuits 14-6 are defective and the output of the AND circuit 15-1 becomes logic 1, the ignition pulse is used as a common input for the defect determination circuits 14-1 and 14-3. The content of ÷1 is determined to be defective. Similarly, the outputs of AND circuits 15-2 and 15-5 are respectively logic 111.
In each case, the ignition pulse φ2. It is determined that the contents of step 6 are defective. In addition, here, thyristor U,
, U.

, U, respectively, but it is by no means limited to this, and other thyristors V, W
, X, Y, and Z are also exactly the same.

In addition, in the embodiment, the time lag of the ignition pulse was used to determine whether the ignition pulse was defective, but if the control output is a voltage, the difference could be determined using the same logic as above. A circuit can be constructed with. In addition, there are 3 control devices
There is no limit to the number of machines, and it does not matter how many machines there are.

As described above, the present invention enables highly accurate monitoring of the output content of the control device by looking only at the output signal of the control device consisting of the gate control element, and when the object to be controlled is applied to a digital control device, the KtfCPU Since the output pulse can be monitored completely independently of the operation of the thyristor, it is not limited to the control use of thyristor control devices, but can be applied to a wide range of applications, and has the remarkable effect of greatly improving the reliability of control contents. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the AC/DC converter section in a conventional AC/DC conversion system, Fig. 2 is an ignition pulse system diagram showing an example of a case where control devices are multiplexed, and Fig. 3 is a diagram of the control output according to the present invention. FIG. 4 is a block diagram showing one embodiment of a defective determination circuit, and is an example in which the defective determining circuit example of the present invention shown in Figure 3 is applied to the example of multiplexing of the control device shown in FIG. be. 1...Transformer, 2...Thyristor, 5-1.5-
2.3-5...control device, 4-1, 4-2, 4-
5.6... Ignition pulse group, 5... Selection device, 16.
... AC/DC converter, 7-1, 7-2, 7-5... Mismatch detection circuit, 8... Mismatch width detection circuit, 9... Color/Re, 10... Tie 1.11. -・Memory, 15-
1.15-2゜15-6...AND circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Makoto Kuzuno (and 1 other person) Figure 1

Claims (2)

[Claims] (1) In a plurality of control devices having a plurality of ignition pulse group output signals in a multiplexed AC/DC converter control device of a DC power transmission system, a corresponding ignition of the ignition pulse group of the plurality of control devices When a deviation of a predetermined value or more exists between a comparison circuit that relatively compares pulses and a plurality of corresponding ignition pulses of the comparison circuit more than a predetermined number of times within a predetermined time, the plurality of 9 control devices are abnormal. 1. A monitoring device for a control device for an AC/DC converter, comprising: a determination circuit for detecting a certain condition. (2) The control device outputs output signals of three or more ignition pulse groups in the AC/DC converter, and the control device compares the corresponding ignition pulses χ of three sets of ignition pulse groups two by two. Claim 1 characterized by comprising a discrepancy detection circuit that determines an abnormality, and a plurality of AND circuits that determine which firing pulse group is abnormal based on the determination result of the discrepancy detection circuit. A monitoring device for the AC/DC converter control device described above.