SU913511A1 - Device for monitoring state of series-connected power diodes of rectifier - Google Patents

Description

The invention relates to the control and protection of high-voltage converters.

A device is known for controlling a circuit of series-connected gates, which contains in each arm of a bridge converter a reacting element included in the diagonal of a bridge formed by a voltage divider connected to the arm and a chain of series-connected shoulder gates [1]

Its disadvantage is the complexity of the scheme.

Closest to the proposed technical means and the achieved result is a device for monitoring the state of series-connected converter valves, containing a voltage divider and reacting bodies connected between a chain of series-connected valves and a divider [2].

The disadvantages of this device are the complexity and large energy losses, reduced reliability and limited functionality.

The purpose of the invention is to simplify and reduce energy losses.

2

The supplied circuit is achieved by the fact that the voltage supporter is connected between the DC poles of the converter and connected to all the reacting organs.

To increase the reliability, the device is equipped with two groups of diodes, each included according to the OR scheme between the circuits of the anodic and cathodic groups of valves and the corresponding reacting organs.

To extend the functionality of controlling a controlled converter, the device is equipped with AND diagrams, IDNs and current sensors of the converter’s shoulders, the inputs of the AND circuit of each arm are connected to the outputs of the reacting body of this arm and the OR circuit, whose inputs are connected to the output of the control system and the current sensor of the opposite arm valves same phase.

FIG. 1 shows a diagram of a device with individual reacting organs for

each transducer arm; in fig. 2 - with common reacting organs for the anodic and cathodic groups of valves; FIG. 3 013511

3

circuit with advanced functionality.

The voltage inverter (see Fig. 1 and 2) is formed by a series connection in each arm of the bridge controlled gates 1 and counter-parallel diodes 2. A voltage divider on the resistors 3-6 is turned on between the DC poles of the inverter. Responsive bodies 7 and 8 are connected between the outputs of the divider and the circuits of the valves. FIG. 3 also shows the schemes AND .9, OR 10, the current centers 11, the control system of the converter 12.

Since in each phase one of the gates is always turned on, the voltage at the non-conductive gate is equal to the voltage at the poles. If all the valves in the circuit are intact, then the voltage of the shoulders of the bridge formed by these valves and the divider is equal and organs 7 and 8 do not work. If one or more valves fail, the voltage on the valve to which the reacting body is connected increases and the latter is triggered.

In the diagram in FIG. 2 only two reacting organs are used, however, if the support valve is damaged, the circuit becomes inoperative, so the support valve must have increased electrical strength.

The diagrams of FIG. 1 and 2 are applicable for single and multi-phase voltage inverters, single-phase current inverters and rectifiers.

In the diagram of FIG. 3, suitable for current and voltage transducers, the control is carried out with the help of high-speed reacting organs, when one arm of the phase is switched on, and the pole voltage is applied to the other.

The signal at the output of the reacting organ appears when one of the valves in the chain is broken or when the opposite arm of this phase is not turned on. Only when the opposite arm is on, which can be when there are control signals on it or a current flows through it, at the output of the circuits

four

OR there will be a signal, and in case of imbalance of the measuring bridge formed by the divider and the valve circuit, the signal from the reacting body passes through the circuit I.,

The device has a simple circuit, reduced energy loss, increased reliability and enhanced functionality.

Claims (3)

Claim 1. A device for monitoring the accessibility of series-connected converter valves, containing a voltage divider and reacting bodies, connected between a series of series-connected valves and a divider, characterized in that, in order to simplify and reduce losses, a voltage divider is connected between the DC poles of the converter and connected to all responding authorities. 2. Device by π. 1, in order to increase reliability, it is equipped with two groups of diodes, each included in the OR scheme between the circuits of the anodic and cathodic groups of valves and the corresponding reacting organs. 3. Device pop. 1, that is, in order to expand the functionality of the controlled converter, it is equipped with AND, OR circuits and current sensors of the converter’s shoulders, and the inputs of the AND circuit of each arm are connected to the outputs of the reacting organ of this arm and the OR circuit, whose inputs are connected to the output of the control system and the current sensor of the valves of the opposite arm of the same phase.