Study on equivalent circuit of the human body and its transient response against electric shock

To solve the problems of the incorrect operation, the failure action and the low operational percentage on Residual Current Operated Devices (RCDs) in the domestic rural power distribution network, an amount of electric shock signals were demanded to study identifying and extracting method of electrical shock current. In this paper an equivalent circuit model of the human body against electric shock was studied. The frequency characteristic of let-go current according to proposed equivalent circuit model of the human body tallied with the testing results of Dalziel [1-2]. Considering the skin was in the dry condition, wet condition and broken-down condition, touch voltage at 106 V rms, electrical contact making at the peak of touch voltage respectively, the simulation results in low-voltage distribution system based on Matlab indicated the feasibility of explaining certain electrical shock phenomenon by the transient response of the equivalent circuit model. The individual responses against electric shocks were simulated by selecting parameters of the human body circuit model correctly. The results showed great potential value for the application of residual current protected devices (RCDs) of different action time as well as the research and development of new type and high reliability RCDs.