Current limited soft connecting/disconnecting device

Abstract

The invention provides a current limited soft connecting / disconnecting device. The device is characterized in that a first winding L1 of a tight coupling double-winding reactor is connected with a first circuit breaker K1 in series, and then is connected with a second winding L2 in parallel; a single branch winding can be connected and disconnected by adopting a circuit breaker with a breaking capacity of 50 percent of short circuit current; after the first winding L1 is disconnected, the reactance of the tight coupling double-winding reactor is increased fast, and the short circuit current of the system is reduced. As the reactance values of various branch windings of the tight coupling double-winding reactor are rationally designed, the tight coupling double-winding reactor can be operated in small reactance and affects the system operation little when the system runs stably; while when the short circuit failure exists, the reactance value of the tight coupling double-winding reactor is increased to a rated reactance of the system, if the system is in a temporary fault, a second circuit breaker K2 is not needed to be disconnected; after the first circuit breaker K1 automatically switches on again, if the short circuit current of the system still exceeds the standard, the first circuit breaker K1 and the second circuit breaker K2 are disconnected in sequence.

Description

technical field [0001] The invention relates to a current-limiting soft-start device. Background technique [0002] With the rapid development of the national economy, the society's demand for electricity continues to increase, which drives the continuous development of the power system. The capacity of single machines, power plants, substations, and loads in cities and industrial centers continues to increase. Interconnection, the level of short-circuit current in power grids at all levels continues to increase. Nevertheless, the general practice is still to use a circuit breaker to break the faulty line, on the one hand to protect the power equipment, and on the other hand to avoid adverse effects on users due to the low bus voltage. As the short-circuit current level continues to increase, it is necessary to continuously increase the breaking capacity of the circuit breaker. To this end, researchers have carried out a lot of research on the electromagnetic and mechanica...

AI Technical Summary

Problems solved by technology

However, during the breaking process of this circuit breaker, the maximum fault current can only be limited to 25%~50% of the system short-circuit current, and it does not have the ability to softly break the line; and the circuit breaker used in the parallel circuit breaker disclosed in this patent The number is also large, and the breaking capacity of the circuit breaker does not drop significantly

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