Optimization Analysis and Experiment Verification of Current Transformer Power Supply Based on Starting Current

In order to improve the efficiency of current transformer power supply in the vicinity of starting current and to reduce the dead zone, we derived a relationship among the output power, filter capacitor voltage, and turns. Then, taking the minimum output power 0.5 W as the target, we simulated the influence of filter capacitor voltage and turns on output power in the vi-cinity of starting current. It is concluded that the maximum power is independent of turns when the voltage drop of rectifier is not considered. However, due to the voltage drop of real rectifier, the curve of maximum power and turns has saturation characteristic, and the turns are determined according to it. It is obtained that the stable operating point is the point of higher filter capacitor voltage by analyzing the stability of the operating point on the output power curve of current transformer. The phenomenon that the power supply may not be able to output normal power in the vicinity of starting current is analyzed, and the solution of controlling the starting of DC-DC circuit is given. A circuit is designed, and the correctness of the analy-sis is verified by experiments. © 2018, High Voltage Engineering Editorial Department of CEPRI. All right reserved.