基于等电位原理的±100Mvar高压STATCOM的弱电网电流闭环测试方法

Current Closed-loop Test Method for ±100 Mvar High-voltage STATCOM in Weak Grid Based on Principle of Equal Potential

在±100 Mvar高压静止无功补偿器STATCOM(static synchronous compensator)的设计中,三角形接线能够耐受短路工况而被采用。大容量STATCOM的波动容易在试验中引起电网过压或过流从而出现故障,因此必须进行专门的测试,以验证整机的绝缘耐压和电流特性。将充电过程和放电过程进行分离,基于等电位原理提出了一种适用于弱电网的高压STATCOM装置电流闭环的测试方案。该方案能够等效产生测试电流,较方便地验证了控制策略中电流采样及电流控制能力,以及整机的绝缘耐压水平。通过Simulink仿真及现场试验,验证了该方案的有效性,为解决高压大容量STATCOM的测试提供了一种新的方法。

In the design of ±100 Mvar high-voltage static synchronous compensator（STATCOM）, triangular connec-tion is adopted owing to its tolerance of short-circuit working condition. The fluctuations in a large-capacity STATCOM will easily lead to over-voltage or over-current in the grid, and thus cause fault. Therefore, a special test is required toverify the insulation and voltage resistance of the complete machine, as well as its current characteristics. In this paper, the charging and discharging processes are separated at first, then a current closed-loop test scheme for the high-voltage STATCOM in weak grid is proposed based on the principle of equal potential. This scheme can equivalently generate the test current, which can conveniently verify the capability of current sampling and current control under the control strategy, as well as the insulation and voltage resistance level of the complete machine. Simulations using Simulink and field tests verified the effectiveness of the proposed scheme. The research in this paper provides a new method for the test of a high-voltage large-capacity STATCOM.