Active residual current leakage switch

Abstract

The invention provides an active residual current leakage switch which is composed of a residual current unit, a voltage phase unit, an active residual current detector, a threshold value controller,a tripping actuator and a circuit breaker. The active residual current detector calculates the residual current and the voltage phase, detects the active residual current in the residual current and inputs the active residual current into the threshold value controller, and after threshold value comparison, the tripping actuator drives the circuit breaker to cut off a power supply so as to play arole of electric leakage protection.

Description

technical field [0001] The invention relates to the field of residual current leakage switches, in particular to an active residual current leakage switch. Background technique [0002] In the series of residual current leakage switches commonly used in the market, the residual current induced by the zero-sequence transformer is the apparent power residual current, including active residual current and reactive residual current. Generally, there is no residual current in the power circuit. The power residual current is so small that it can be ignored, so it is not wrong to use the apparent power residual current to judge the leakage degree of the power circuit in the commonly used residual current leakage switch; but when the distributed capacitance to the ground in the power circuit When it is large, the residual current will contain a large reactive residual current. For example, in the electric floor heating system, the distributed capacitance of the heating circuit to th...

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Problems solved by technology

[0002] In the series of residual current leakage switches commonly used in the market, the residual current induced by the zero-sequence transformer is the apparent power residual current, including active residual current and reactive residual current. Generally, there is no residual current in the power circuit. The power residual current is so small that it can be ignored, so it is not wrong to use the apparent power residual current to judge the leakage degree of the power circuit in the commonly used residual current leakage switch; but when the distributed capacitance to the ground in the power circuit When it is large, the residual current will contain a large reactive residual current. For example, in the electric floor heating system, the distributed capacitance of the heating circuit to the ground is very large, and the capacitive reactive residual current generated can reach hundreds of milliamperes. Therefore, the ordinary residual current leakage switch cannot work normally

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