SU1309104A1 - D.c.contactor with arcless switching - Google Patents

Abstract

The invention relates to switching electrical apparatus and is intended for the arc-free switching of electrical circuits (1 STATE) current. The purpose of the invention is to reduce the contactor gabargov. The goal is achieved by enforcing the block. Commmuth Rbiiio.jiicii iio bridge circuit, in the two opposite arms of which are included electrolytic capacitors 5 and 6, and in two different lono. iiintelle semiconductor 1 switch: 1 (PC) 3 and 4. In the first diagonal of Mocror.oii circuit: switched PC 7 is switched on, one output of the second diagonal is connected to; . resistor 8, the other - on the output terminal of the contactor. The control outputs of the auxiliary PC and switching PCs 3 and 4 and 7 are connected to the outputs of the control unit () av.1eni. 1 il. SO About about 4:

Description

This invention relates to switching electrical apparatus and is intended for arc-free. switching electric circuits of direct current.

The purpose of the invention is to reduce the dimensions of the DC contactor with arc-free commutation.

The drawing shows a diagram of the contactor.

The contactor contains contact 1, in parallel with which a semiconductor switch 2 is connected, a forced switching unit with a charging circuit consisting of additional semiconductor switches 3 and 4, switching electrolytic capacitors 5 and b, switching switching semiconductor switch 7 and a charging current limiting resistor 8 and a block 9 control, controlling the semiconductor switches 2, 3, 4 and 7. The source of the direct current source 10 is connected to the input of the coactivator, and the load is connected to the output, which is clamped by a diode 12, excluding the effect of inductive load on the operation of the contactor.

The contactor works as follows.

When the contactor is turned on, its contact 1 closes and a load current begins to flow through it in the direction indicated by the arrow.

When the contactor is disconnected at the beginning of the opening process of contact 1, the semiconductor switch 2 is turned on by the control unit 9. The load current from the contact circuit 1 enters the semiconductor key circuit, which remains open until the opening process of contact 1 is completed, thereby ensuring its arc-free opening. Simultaneously with switching on the semiconductor switch 2, the control unit 9 turns on additional semiconductor switches 3 and 4. Switching capacitors 5 and 6 are charged along the circuit positive terminal of current source 10 - semiconductor switch 2 - additional semiconductor switch 3 - capacitor 5 (capacitor 6 - additional semiconductor switch 4) - charging resistor 8 - negative output of current source 10. The charging time of the switching capacitors 5 and 6 can be limited by an appropriate choice of the charging resistor 8 to 1-2 ms, which is significantly less than the opening time of the main contact (10-20 ms), so that charging the capacitors 5 and 6 is enough the open state of a semiconductor key 2.

Compiled by G. Korsakov

Editor N. LazarenkoTehred I. VeresKorrektor I. Muska

Order 1440/45 Circulation Subscription

VNIIPI USSR State Committee for Inventions and Discoveries

113035, Moscow. Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, ul. Project, 4

The polarity of the charge of the switching capacitors 5 and 6 is shown in the drawing.

After the charging process of the capacitors 5 and 6 has been completed and the charging currents in the additional semiconductor switches 3 and 4 have declined to zero, the latter are locked.

Upon completion of the opening process of contact 1, control unit 9 switches on switching semiconductor key 7. Capacitors 5 and 6 are connected in series and discharged in two circuits: through semiconductor key 2, current source 10 and charging resistor 8, while current through semiconductor key 2 will drop to zero and the semiconductor switch 2 will not close; through the load 11 and the charging resistor 8, until the current through the switching semiconductor switch 7 drops to zero and the switch 7 closes.

This completes the arc-less switching process of the contactor.

Thus, during the operation of the proposed contactor, there is no recharge of the switching capacitors, which allows the use of electrolytic capacitors, reducing the size and cost of the capacitive forced switching unit and the contactor as a whole.

Claims (1)

Invention Formula DC-free contactor with arc-free commutation, containing a contact, shunted by a semiconductor switch with a control input, a forced switching unit with a charging circuit containing a resistor, a control unit, the first output of which is connected to the control input of the semiconductor switch, and the remaining outputs are connected to the unit forced switching, characterized in that, in order to reduce the size of the contactor, the forced switching unit is made according to a bridge circuit, and in two opposite arms of a bridge c Additional semiconductor switches are included, two other opposite arms - switching electrolytic capacitors, a switching semiconductor switch included in one of the diagonals of the bridge circuit, the first output of the second diagonal of the bridge circuit is connected to a charging resistor, the second output - to the output terminal of the contactor, controlling The commutation and additional semiconductor switches are connected to the outputs of the control unit.