Abstract:

From the equivalent model of the mine power network in terms of electric shock safety applying the classic integral method, the author has built the expression of current through measuring device of the earth leakage current protection equipment using DC current for monitoring the insulation resistance of underground mine power networks using semiconductor converters (combined networks). On the basis of the analysis of the obtained expressions, the conditions of safe and unsafe use of leakage current protective equipments using DC measurement current have been determined in combined power networks. The results of this study are the basis for recommending a new solution to monitor the insulation resistance of combined power networks, which are increasingly widely used in underground mine power networks in Vietnam.