SU81933A1 - Device for switching on and off of direct current circuits - Google Patents

Description

In the known devices for switching on and off high voltage DC circuits, the main ion gate is controlled by cutting a single wire of the circuit and, in parallel with it, a high-voltage switching capacitor, a constant ion capacitor with a second auxiliary control. To turn on the DC line, the blocking voltage is removed from the control grid of the main ion valve and the auxiliary valve is closed.

To turn off the line, the auxiliary valve is unlocked, which closes the discharge current circuit high on the voltage switching capacitor connected in parallel with the main ion valve. A capacitor creates an oscillating bit that. if there is a countercurrent in the main valve circuit, it makes it possible to lock it.

In order to reduce the inrush current during a short circuit in the disconnecting line, inductive resistance is switched on in series with the main ion valve.

When the ionic valves are operated as switches, a considerable overvoltage in the network arises, which can cause the output of the equipment, due to the breakdown of the insulation. With high short-circuit currents, a high-voltage switching capacitor of considerable capacity is required to create the necessary conditions for mashing the main shut-off valve.

In the described device, in order to reduce overvoltages in cCtejMe when the short-circuit currents are disconnected, the inductive impedance is controlled by a controlled valve with a series-connected ohmic impedance, and to reduce the switching capacitor capacitance and facilitate locking

the main valve is intended to install a second high-voltage capacitor with a valve device connected in parallel to the line.

Diagram of the device for switching on and off the DC circuits shown in the drawing.

In series with the main ion valve / inductive resistance 2 is switched on, shunted by controlled valve 3 and ohmic resistance 4 connected in series with it, as well as by a high-speed mechanical switch 5. At the moment the current in the switchable circuit starts to decrease, valve 3 must be open and switch 5 is turned on, and when current increases, valve 3 is locked and switch 5 is turned off.

Inductive resistance 2 in this case will prevent the increase of the current and will be bridged when the current drops, which will reduce the overvoltage in the system.

An additional capacitor 6 is connected in parallel to the line to the switching point of the main ion valve 1. During normal operation of the line, the controlled ion valves 7, 8 and 9 are closed and the capacitor 6 is constantly recharged from the network through the controlled valve 10 and resistances // and 12.

When the line is disconnected by the ion valve 1, the valve 8 is opened and the capacitor 6 is discharged to the supply network and thus reduces the amount of current flowing through the valve /, which facilitates the locking of the ion valve 1 and reduces the capacity of the switching capacitor 13.

Subject invention

Claims (3)

1. Device for switching on and off of DC circuits, consisting of the main ion valve (rectifier), switching capacitor, switching valves, ohmic and inductive Active resistance, characterized in that, in order to reduce current jolt and overvoltages in the supply network, the inductive resistance included in the main circuit is shunned by a valve (rectifier) with a series-connected ohmic resistance. 2. The device according to claim 1, wherein, in order to reduce the capacity of the switching capacitor, a second capacitor with a valve m (rectifier) and ohmic power supply is connected in parallel to the main network. 3. The device according to claim 2, characterized in that a high-speed mechanical switch is connected in series to the main current circuit in series with inductive resistance. -3- № 81933