JPS63136962A - Bypass pair control of control rectification device - Google Patents

Abstract

PURPOSE:To operate bypass pair simply and assuredly, by adding a logical control circuit to prohibit the input of firing pulse from other controlled rectifier when a bypass pair is put to work. CONSTITUTION:This is a controlled rectifier device comprising two controlled rectifiers connected in series. More specifically it comprises transformers for rectifier 2-1-2-2, control rectifiers 3-1-3-2, an inductive load 4, a DC current detector 5, an instrumentation transformer 6, a current regulator 7, phase control circuits 8-1-8-2 and a firing pulse distribution control circuit 9. On this occasion, a logical control circuit 10 is provided, to which and to the phase control circuits 8-1-8-2 is inputted a bypass pair operation command signal. This logical control circuit 10 ANDs the firing pulse and the reverse signal of a bypass pair operation command signal, prohibiting the input of the firing pulse in putting the bypass pair operation signal and yielding no output. The bypass pair operation can thereby be effected.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a method of controlling a controlled rectifier for causing current to flow through an inductive load, and particularly relates to a method of controlling a controlled rectifier for causing current to flow through an inductive load. The present invention relates to a method for controlling a bypass pair of controlled rectifiers connected to each other.

(Prior art) In the case of a polyphase controlled rectifier configured by connecting multiple unit controlled rectifiers in series, the commonly used double pulse method is used because the AC voltage phases between the unit controlled rectifiers are different. If the unit control rectifiers are individually controlled by the following, the following problems will occur and operation will not be possible.

■ Cannot start because load current does not flow during startup.

■ When the current drops below the holding current of the control rectifier near zero, it stops and the current does not flow again.

For this reason, conventionally, the ignition method using long pulses (hereinafter referred to as ``r ignition pulse control 1'') and the ignition pulse to the unit control rectifier with different voltage phases of the II current transformer are mutually ORed. , When one phase of the unit control rectifier commutates, a method of controlling the ignition pulse so that the ignition pulse is also input to the phases of all other control rectifiers that are energized at that time (hereinafter referred to as [ignition pulse control 2 ”).

The former "R ignition pulse control 1" requires complicated control rectifier gate circuits and related peripheral circuits;
Low voltage (approximately 100 OV or less) and small capacity (several hundred KV or less) power supplies are extremely uneconomical and impractical.On the other hand, the latter 'r ignition pulse control 2' This ignition pulse control method is generally used because control can be achieved by simply adding a simple control circuit to the final stage.

FIG. 2 shows the above-mentioned r ignition pulse control 2 in the ignition pulse method.
2 shows a block diagram of a conventional example of a controlled rectifier constructed by connecting two controlled rectifiers in series using the same method. In FIG. ,
3-1.3-2 is a control rectifier that converts alternating current voltage into direct current, 4 is an inductive load, and 5 is a direct current detector that detects the current flowing through the load. 6 is a controlled rectifier 3-1.3-
2 is a potential transformer (PT) for detecting a reference for the firing angle that controls 7, a current reference 51 and a DC current detector 5;
A constant current control circuit 8-1 controls the current to a constant value by inputting the difference between the detected load current 52 and the output of the voltage transformer 6. A phase control circuit that determines the ignition timing and controls the phase of the control rectifier 3-1; 8-2 is a phase control circuit that similarly controls the phase of the control rectifier 3-2; 9-2 is a phase control circuit 8-1.8 -2
The ignition pulse distribution control circuit inputs the output of the ignition pulse signals 53-3 and 53-4 to the control rectifiers 3-1 and 3-2. In order to make the U1 phase of the controlled rectification fJ3-1 and.

Although only a block diagram of the distribution control of the ignition pulse inputted to the U2 phase of the control rectifier 3-2 is shown, the same block diagram is shown for the other phases. In addition, the phase control circuit 8-
1.8-2 is a conventionally known control circuit, e.g.
-96351 "digital phase control circuit" etc. is sufficient.

In FIG. 2, the ignition pulse output from the phase control circuit 8-4.8-2 is input to the ignition pulse distribution control circuit 9-2, and the ignition pulse is sent to the control rectifier 3-1.3-2. pulse 5
3-3 and 53-4 are distributed and controlled by the method of "ignition pulse control 2" described above and output.

FIG. 3 shows the operating voltage waveform when the controlled rectifier 3-1.3-2 in FIG. The ignition pulse and its timing are shown.

In FIG. 3, (a) shows the operating voltage waveform of the control rectifier 3-1 and the output pulse UIP-V of the one-phase control circuit 8-1.
(b) shows the timing of IP, and the operating voltage waveform of the control rectifier 3-2 and the output pulse U of the phase control circuit 8-2.
For convenience of explanation, the voltage phases of rectifier transformers 2-1 and 2-2, which indicate the timing of 2P-Y2P, are (a) and (b).
) - (C), (d)
;Y1 ignition pulse distribution control circuit 9-2 output 53-3
, 53-4, the timings of the ignition pulses input to the U1 to Y1 phases of the control rectifier 3-1 and the U2 to Y2 phases of the control rectifier 3-2 are shown. In this figure, for example, it is assumed that the 01 and Z1 phases of the controlled rectifier 3-1 and the U2 and z2 phases of the controlled rectifier 3-2 are energized. In this state v1
When commutating to the z1 phase and the U2 . It can be seen that it is also input to the Z2 phase.

As explained above, in normal operation, the control rectifier in which unit control rectifiers are connected in series can be easily controlled by "r firing pulse control 2".

(Problems to be Solved by the Invention) By the way, bypass pair operation has conventionally been performed as one of the protective operations of the controlled rectifier.

Bypass pair operation is a protective operation in which a pair of control rectifier elements connected to the same phase on the AC side of a control rectifier are simultaneously energized, the DC load is short-circuited, and the load current is attenuated by the load's own time constant. Used in the event of an accident on the AC side, such as overcurrent or AC undervoltage. In the above-mentioned controlled rectifying device, when an attempt is made to protect the controlled rectifying device by putting the controlled rectifying device into bypass pair operation in the event of an accident on the AC side, for example, the following problems occur.

FIG. 4 shows the control rectifier when a bypass pair operation command is input to the phase-cut circuit 8-1.8-2 while operating in the state shown in FIG. 3! (a) shows the operating voltage waveform of 13-1.3-2 and the ignition pulse actually input to each phase of the control rectifier ff13-1.3-2 when the bypass pair operation command is input. is the operating voltage waveform of the control rectifier 3-1, the V11 phase post-arc bypass pair operation command is input, the phase control circuit 8-1 cuts the X1 phase firing pulse, and the pulse is input to the W1 phase eight points. Attempts to become a ziwi phase bypass pair. At this time, the ignition pulses input to each phase are shown in (c), and (b) is the control rectifier 3.
-2 operating voltage waveform. The Z22 phase post-arc bypass pair operation command is input, the phase control circuit 8-2 cuts the v2 phase firing pulse, the X2 phase eight firing pulses are input, and the U2. Attempts to become an X2 phase bypass pair. At this time,
The ignition pulses input to each phase are shown in (d), (C)
, (ci), the actual ignition pulse is generated by U2 and X of the controlled rectifier 3-2 as explained in FIG.
When the ignition pulse is input to the 2nd phase, U of the control rectifier 3-1
l.

Ignition pulses are also input to the Vl, Xi, and Vl phases. Therefore, in the control rectifier 3-1 after the bypass pair operation command is input, after commutation to the X1 phase, the ignition pulse is input to the Zl and w1 phases which are the bypass pair phases, and the Zl phase is .

Due to the reverse pressure period, bypass pair operation will not occur, and X
The l and w1 phases remain fired. In addition, in the control rectifier 3-2, after becoming a U2X2 phase bypass pair, the ignition pulse is input to the V2 phase, so it is commutated to the V2 phase and released from bypass pair operation, and the V2 and X2 phases are ignited. It remains as it was.

Also, Ul, Yl, U2. In the Y2 phase, since the ignition pulse is input during the reverse pressure period, the controlled rectifier has the problem of not being able to perform bypass pair operation, which causes element deterioration.

The object of the present invention is to solve the above-mentioned problems in a controlled rectifier that connects a plurality of unit control rectifiers in series and uses the above-mentioned "R firing pulse control 2" as a single firing pulse method.
An object of the present invention is to provide a bypass pair control method for a controlled rectifier that allows easy bypass pair operation.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides for controlling the control rectifier when a bypass pair operation is required, such as when a failure occurs on the AC side or the DC side and a protective stop is performed in the control rectifier. In order to enable bypass pair operation, once a bypass pair operation command is input, the input of an ignition pulse at the timing to ignite another unit control rectifier is prohibited.

(Function) In the control rectifier using the above-mentioned r ignition pulse control 2 as the ignition pulse method, when performing bypass pair operation, the bypass is prevented by prohibiting the input of ignition pulses from other control rectifiers. Pair operation is possible.

(Example) As an example of the present invention, a block diagram of a controlled rectifier configured by connecting two controlled rectifiers in series is shown below, using the above-mentioned ignition pulse control 2 as the ignition pulse method. 1st
As shown in the figure. Blocks with the same functions as those explained in the conventional example of FIG. 2 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In FIG. 1, 54 is a bypass pair operation command signal which is input to the phase control circuits 8-1, 8-2 and the logic control circuit 10. 9-1 is an ignition pulse distribution control circuit which inputs the output of the phase control circuit 8-1.8-2 and outputs the ignition pulse 55-1.55-2 to be input to another control rectifier through a logic control circuit. Go to 1o. The logic control circuit 10 generates a firing pulse 5
5-1.55-2 and the inverted signal of the bypass bare operation command signal 54, and the bypass pair operation signal 54 is obtained.
When using manual power, the input of ignition pulses 55-1 and 55-2 is prohibited and the output is not output, and the bypass bare operation command signal 5
When 4 is not input, that is, 1 during normal operation,
The ignition pulses 55-1 and 55-2 are output as they are to the ignition pulse distribution control circuit 9-1. Therefore, the ignition pulse distribution control circuit 9-1 uses the outputs of the phase control circuits 8-1 and 8-2 and the output of the logic control circuit 1o to control the control rectifier 3-1.
．． In FIG. 6, the block diagram of the ignition pulse distribution control circuit 9-1 and the logic control circuit 10 is U1 of the control rectifier 3-1. It is a block diagram of the ignition pulse input to the U2 phase of the control rectifier 3-2, and the other phases are omitted, but the same block diagram is shown for the other phases.

The operation of the present invention will be explained below with reference to FIG. Assume that a bypass pair operation command signal 54 is input. The bypass operation command signal 54 is transmitted to the phase control circuit 8-1.8-2.
and a 1-phase control circuit 8- input to the logic control circuit 10.
1.8-2 stores the current energization phase and outputs the ignition pulse of the phase that should be the bypass pair of the control rectifier 3-1.3-2 to the ignition pulse distribution control circuit 9-1. The firing pulse distribution control circuit 9-1 outputs the bypass pair phase firing pulses ss-1 and 5s-2 to the logic control path 10 as in the normal operation. However, since the bypass pair operation command signal 54 is input to the logic control circuit 1O, the input of the ignition pulses 55-1 and 55-2 is prohibited as described above, and the output of the logic control circuit 1O is It is not input to the ignition pulse distribution control circuit 9-1.

Therefore, the output 53-1 of the ignition pulse distribution control circuit 9-1
The output 53-2 is only the bypass pair phase firing pulse outputted from the phase control circuit 8-1, and the output 53-2 is only the bypass pair phase firing pulse outputted from the phase control circuit 8-2. Since the ignition pulses that are input to the other control rectifiers are not input to the control rectifier 3-1.3-2, the control rectifier 3-1.3-2 operates as a bypass pair, such as 0 or more. , when the bypass pair is turned on,
Bypass pair operation becomes possible by using a bypass pair control method that prohibits the input of an ignition pulse at the timing to ignite another control rectifier.

Although this example describes a controlled rectifier configured by connecting two controlled rectifiers in series, a similar bypass pair control method can also be used for a controlled current device configured by connecting multiple controlled rectifiers in series. Bypass pair operation becomes possible.

〔Effect of the invention〕

As explained above, as a method of connecting a plurality of unit control rectifiers in series and applying the ignition pulse to the control rectifier, the r
In a controlled rectifier using ignition pulse control 2, adding a logic control circuit that prohibits the input of ignition pulses from other control rectifiers when a bypass pair is turned on allows for easy and reliable bypass pair operation. A method for controlling a bypass pair of devices can be provided.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a conventional device, Fig. 3 is an operating voltage waveform diagram and a timing diagram of an ignition pulse, and Fig. 4 is a diagram showing defects. FIG. 3 is an example operating voltage waveform diagram and firing pulse timing diagram. 1... AC bus, 2-1.2-2... Rectifier transformer, 3-1.3-2
...Controlled rectifier. 4... Inductive load, 5... DC current detector, 6... Instrument transformer, 7... Constant current control circuit, 8-1.8-2... Phase control circuit. 9-1.9-2... Ignition pulse distribution control circuit, 10.
...Logic control circuit, 51...Current reference, 52
...Load current, 53-1 to 53-4.55-1.55-2...Ignition pulse signal. 54...Bypass pair operation command signal. Agent Patent Attorney Nori Chika Yudo Hirofumi Mitsumata

Claims (1)

[Claims] If multiple unit control rectifiers are connected in series and the ignition pulses to the unit control rectifiers with different voltage phases of the rectifier transformers are ORed, if one phase of the unit control rectifier commutates, then In a controlled rectifier that uses a ignition pulse control method that controls the ignition pulse to be input to the energized phase of all other energized unit control rectifiers, when the bypass pair is turned on, the other unit control rectifiers 1. A bypass pair control method for a controlled rectifier, characterized in that input of an ignition pulse at the timing for igniting a controlled rectifier is prohibited.