Electric leakage locking sampling circuit and detection method

Abstract

The invention discloses an electric leakage locking sampling circuit and a detection method. A detection circuit is used for injecting a direct current signal into a to-be-detected leakage resistor, acquiring a to-be-detected leakage resistor feedback signal, and transmitting the collected feedback signal to the pi-type filtering circuit; filtering processing is carried out on the collected feedback signal through the pi-type filtering circuit, and the filtered signal is fed back to an adaptive filtering circuit; and the adaptive filtering circuit is used for separating an alternating-currentsignal in the filtered signal and reversely superposing the alternating-current signal in the filtered signal to be counteracted with the alternating current signal in the filtered signal to obtain awave eliminating signal, and transmitting the wave eliminating signal to a shaping circuit for level adjustment and then to be output, so that the influence of residual voltage on the detection circuit can be effectively eliminated; the adaptive filtering circuit is adopted, so that the influence of clutter induction voltage on the detection result is effectively inhibited, and the adaptive filtering circuit solves the problems of influence of residual magnetism voltage on the electric leakage locking detection circuit and damage to the electric leakage locking circuit caused by a reverse filling current.

Description

technical field [0001] The invention belongs to the technical field of explosion-proof electrical appliances, and relates to a leakage blocking sampling circuit and a detection method. Background technique [0002] Leakage lockout is a feed switch or electromagnetic starter that detects the breaking state——the insulation resistance of the load side to the motor case, if it is lower than the set value, it cannot be closed to transmit power, which belongs to preventive detection. Preventive detection and protection in flammable and explosive environments is particularly important; [0003] image 3 It is a schematic diagram of the current leakage blocking detection of the existing low-voltage feeder switch, which is usually put into detection at the same time as the main contact KM of the switch is broken. However, due to the distributed capacitance of the wiring and other reasons, the object under test already has an induced electromotive force, which can be simplified as the...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a leakage blocking sampling circuit and a detection method to overcome the problems of low detection accuracy and inaccurate detection in the existing method that the back-feeding current is easy to damage the detection circuit and the residual magnetic voltage affects the leakage detection circuit.

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