Research On Detection Method Of The Impact-Resistance Ac Weak Signal

The main content of this paper is the detection method research on the impact-resistance AC weak signal, it was mainly aiming at the lose efficacy of the surge protective device. In the tests, it could resist the impact of the heavy current which was under50kA, and could exactly measure the AC weak signal which was in the range of1-20mA.On the base of analysing the common method of the current measurement, it was measured the impact AC weak signal separately in the method of hall-type, giant magneto-resistive and mutual inductive measurement.It was introduced the working principle of the three measure methods, designd three measuring plan and measuring circuit, validated the feasibility of the three measuring method by experiments, compared the advantages and disadvantages of the three methods. It was emphatically analyzed mutual inductive measurement, established the dynamic modle and analyzed the impact-resistance principle of the measurement.The experiment showed that all of the three measuring methods could resist the impact of the heavy current, but the mutual inductive measurement was better than the others. The research in this paper had a practical guidance on the measure of impact AC weak signal in lightning protection system and electric power equipments.