特高压直流输电系统DCCT现场校验用的电流标准源研究

大功率高精度电流标准源是HVDC输电系统中直流电流互感器现场校验用的关键设备之一,但目前已商业化的电源设备无法同时满足现场校验用的多重要求,如功率大、精度高、便于携带以及可满电流多量程调节等。本文考虑现场校验用电流标准源工作过程中负载不变,只存在供电电压扰动及多量程调节需要,研究了一种交错并联移相全桥倍流整流电路结构,并基此模型设计了小惯性电流跟踪控制器,通过仿真实验验证了该电流标准源输出精度达到0.002级,满足校验0.5级、0.02级以及0.01级电流互感器现场校验用的电流标准源精度要求。

Research on Current Standard Source for Calibrating DCCT in UHVDC Transmission System

High-power and high-precision standard current source is one of the key equipment for the field calibration of DC current transformer in high voltage direct current(HVDC) transmission system. However,at present, the power supply equipment cannot meet several requirem ents for the field calibration at the same time. This paper considers that the standard current source loads constantly for field calibration, and during the process of running only a need exists for DC input voltage disturbance and multi-range regulation. By studying current double rectifier circuit structure of an interleaved parallel phase shift full bridge of small inertia current tracking controller is designed. The simulation results show that output accuracy of the current standard source reachs to 0.002 level, which meets the accuracy requirements of the current standard source for field calibration of class 0.5, 0.02 and 0.01 current transformers.