In order to solve the problems of lack of effective calibration means for the two key test performance indices “delay characteristics” and “precision” in the technical performance of substation merging unit(MU)test equipment

a calibration method for the technical performance of substation MU test equipment is proposed. The corresponding calibration system is developed

and the composition of the calibration system and its technical indices are described. Based on the hardware system of “high performance ARM processor+FPGA+high precision AD chips”

the high-speed voltage and current sampling pre-circuit is designed to reduce the sampling delay error. And the fixed frequency sampling high-precision amplitude and phase measuring algorithm is adopted for high-precision sampling value measurement. A precise and flexible test strategy for time delay is adopted. Finally

the comparison test of the MU testing equipment using the calibration system has been carried out. The practical problem that the core performance of substation MU test equipment cannot be tested is basically solved.