SU702455A1 - Device for controlling the condition of series connected rectifiers of a converter - Google Patents

Description

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This invention relates to the protection of converters in direct-current power lines.

A device is known for controlling a postconductively connected converter valve, which contains a voltage divider, which forms a bridge with the selective circuit of controlled valves, the diagonal of which includes a separate organ. However, insufficiently high balancing of the bridge affects the operation of the device and makes it dependent on the operating conditions of the converter.

Closest to the invention is a device for monitoring the state of serially connected converter valves, in parallel with which PC – pep containing a voltage divider, forming a bridge with a consistent pep of controlled valves, in which diagonal is connected an output organ with an actuating element at outlet 23.

The disadvantage of this device is the dependence on the operating conditions of the converter, i.e. low reliability

In order to increase reliability, the proposed device is supplied with rectifiers connected to the support: bridge shoulders, additional RC-switches (p 1, separating 1 diodes and a control key, forming a comparison circuit, at the output of which a switching element is switched on via dividing diodes the key is connected between the cathodes of the separation diodes and, negatively, the gaos of the converter.

The drawing shows a diagram of a sequential state control device,. Tight connected valves

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Claims (2)

The proposed device contains in the illustrative organ a comparison circuit on rectifiers B and b, resistances R and RI, capacitors C and C, G. Dissipative diodes D: and D, complete key (thyristor) T) current transformer TT and an executive element of IE. The voltage taken from the supporting shoulders of the bridge, formed by a thyristor cell T; and the resistor Rg, charges through the rectifier B (B |) and the charge resistance R {R) of the capacitor C 4 according to the sampling frequency of the thyristor Tj, these capacitors are discharged and compared with the output / signal of the current transformer TT to the actuator IE. The phase non-dependence of the process is due to the fact that by the time the key TC triggered, the voltage on C and Cj is equal to some Averaged Amplitude value of the value of Nai Krany taken from the corresponding reference arm of the bridge. The invention is a device for monitoring the state of serially connected converter valves, in parallel with which RC circuits are connected, containing a voltage divider, forming a bridge with the output pendulum of controlled valves, to the supporting arms of which an output element is connected Of course, in order to increase reliability and accuracy, it is equipped. connected to the supporting arms of the bridge with rectifiers, additional I C-uyp my, dividing diodes and a control key, forming a comparison circuit, at the output of which an operating element is connected through dividing diodes, and a control key is connected between the cathodes of dividing diodes and the negative pole . Sources of information taken into account in the examination 1. USSR author's certificate number 431963, cl. H 02 H 7/10, 1971. 2. Semiconductor rectifiers. M., Energie. 1967, p. 394. d.