Research On Residual Current Protector Based On Amplitude Discrimination And Phase Demodulation

With the widely application of the electric power, and due to improper use electricalequipment or circuits leakage caused by electric shock events have occurred, the researchand practice of third residual current protection are carried out widely at home and abroadso as to ensure the safe use of electricity. As a kind of low voltage protective electricappliances, residual current protector can be used to prevent leakage fire caused byeconomic losses and casualties caused by a person who gets an electric shock, so graduallyhas been widely applied.The residual current protector can effectively reflect the size of the residual currentamplitude, but it can’t well reflect its phase information, and the existence of dead zone inresidual current protection has a great potential safety hazard in some cases. Theapplication of single-chip microcomputer technology can not only bring huge economicbenefits for people, but also can replace the conventional measuring circuit of traditionalinstruments, which fundamentally changes the design idea and the design method oftraditional control system. Single-chip microcomputer technology which is applied to theresidual current protector can improve its operating reliability, and at the same time it canalso greatly promote the intelligence of residual current protector. When the leakage ofcircuit occurs, applying the evaluation phase type of residual current protector can morereliably to cut off the fault circuit, which can more accurately reflect the phase informationof residual current.This topic regards the protective methods of residual current as the research object.On the basis of analyzing the traditional method of residual current protection, this topicsummarizes the shortcomings and the deficiencies, and puts forward the protectivemethods of the evaluation phase type residual current. The calculation methods of thegraded residual current and the mutations in residual current are respectively referred to inthis topic and their simulation is also accomplished by matlab. The simulation results prove that the proposed method of the evaluation phase type residual current is feasible. Thissubject adopts single-chip microcomputer technology in hardware design and softwaredesign: Hardware design includes single processing circuit, phase processing, actionexecution circuit, power circuit, etc; Software design includes the initialization module,graded residual current module, residual current mutation module, etc.