Application of strong and weak current control of circuit breaker terminal block

The control mode and selection of high voltage circuit breaker in the substation of circuit breaker terminal are related to the control mode of substation and the scope of substation. The control style and scope of circuit breaker terminal substation are different, and the control style of circuit breaker terminal circuit breaker is also different accordingly.

According to the working voltage of the control circuit, the control mode of the circuit breaker can be divided into strong current control and weak current control. According to the operation mode, the circuit breaker terminal can be divided into one-to-one control and line selection control.

The so-called strong current control means that the working voltage of the whole control circuit is DC 110V or 220V from the control equipment that sends out the operation command to the operating mechanism of the circuit breaker. According to the control address, it can be divided into centralized control and on-the-spot control; according to the tripping and closing circuit supervision, it is divided into light supervision and sound supervision; according to the control circuit wiring, the circuit breaker terminal is divided into the control switch with fixed position of the corresponding wiring and the control switch contact automatic reset wiring.

The wiring of weak current line selection control is complex, and the operation steps of circuit breaker terminal blocks are more, so its reliability is difficult to guarantee. Weak current line selection control is not recommended for circuit breakers in 220-500kV substations.

The coordination feature of weak current control is that the miniaturized weak current control equipment is adopted on the control panel (table), and there are many control circuits that can be inserted in unit area on the control panel (table) of circuit breaker terminal. In the case of the same number of controlled objects, compared with the strong current control, the area of the control panel can be reduced, which is convenient for the operator to supervise and operate; the building area of the main control room is reduced, and the civil engineering investment is reduced. This is the main advantage of weak current control.

Strong current control is divided into strong current one-to-one direct control and strong current line selection control. The latter is seldom used in practical engineering. The strong current one-to-one direct control system has the advantages of simple control circuit, single operating power supply voltage, easy to master, easy to maintain and reliable for circuit breaker terminal operators. The circuit breaker terminal is one of the main control methods adopted in various domestic substations.

At present, the control system adopted is: strong electricity one-to-one direct control, the station does not set up a conventional control panel, through the self-control device to achieve control. The old station is also gradually reformed according to the style