Three-phase electric switching interlock protection circuit

Abstract

The invention provides a three-phase power switching interlocking protection circuit. The protection circuit comprises a logic circuit (1) and a control circuit (2) connected with output ends of the logic circuit. The output ends of the logic circuit include three single-phase power output ends (11), a switching-off output end (12) and a switching-on output end (13), wherein the three single-phase power output ends (11) are respectively connected with three single-phase power input ends (11) of the control circuit, the switching-off output end is connected with a switching-off control end of the control circuit, and the switching-on output end is connected with a switching-on control end of the control circuit. Through the design in which the logic circuit and the control circuit are connected, strict control is carried out logically to enable power of only one of the three phases to be output as working voltage at any time and to enable either a switching-off action or a switching-on action to be performed at the same time. Compared with an existing circuit, the three-phase power switching interlocking protection circuit is higher in stability, much lower in cost and much smaller in size.

Description

technical field [0001] The invention relates to a three-phase electric switching interlocking protection circuit, in particular to a three-phase electric switching interlocking protection circuit which logically eliminates the possibility of selecting multi-phase electrics at the same time. Background technique [0002] The switching of three-phase alternating current is an essential link in the process of three-phase alternating current supply, and its importance is self-evident. The voltage of one or two phases is abnormal, which cannot meet the needs of base station equipment. In this way, a switching device is needed to switch between the three phases to ensure that when a certain phase fails, it can Switch to the normal operating phase in time, so as not to affect the normal power supply of the circuit. [0003] At present, the switching of three-phase AC power is completed by successively pulling in and breaking different relays. In order to ensure reliable switching ...

AI Technical Summary

Problems solved by technology

[0002] The switching of three-phase AC power is an indispensable link in the process of three-phase AC power supply, and its importance is self-evident. During the entire AC power supply process, failures often occur due to some interference or line problems, which will cause The voltage of one or two phases is abnormal, which cannot meet the needs of the base station equipment. In this way, a switching device is needed to switch between the three phases to ensure that when a certain phase fails, the Switch to the normal operating phase in time, so as not to affect the normal power supply of the circuit

This will increase the cost of investment, and a large number of detection circuits will also increase the complexity of the circuit. If there is a problem with the detection circuit, it will affect the effect of circuit switching, and even a short circuit between phases will occur, that is, the phase voltage Change to 380V, causing an accident

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