配电变压器集成式级联STATCOM原理与设计

Principle and Design of the Cascaded STATCOM Integrated with Distribution Transformer

配电网无功补偿能够有效减少电能损耗,提升供电质量,以配电变压器作为无功控制的节点充分利用配电变压器富余容量,提出一种与配电变压器相集成的级联静止无功发生器(STATCOM)装置。将级联型STATCOM通过Dyn11配电变压器高压侧三角形绕组抽头接入系统,研究通过抽头注入电流实现无功补偿的机理,分析注入电流对绕组电流分布的影响,充分利用变压器绕组的载流能力设计合理的接入点电压等级和补偿容量。针对配电变压器集成式级联STATCOM结构特点,提出改进的无功指令电流检测方法,采用非线性无源控制实现指令电流跟踪,提升控制系统的鲁棒性。仿真与实验结果验证了提出方案的有效性。

Reactive power compensation has been widely used in distribution networks to decrease power losses and enhance voltage quality. To make full use of the spare capacity of the distribution transformer to achieve reactive compensation, this paper presented a cascaded static synchronous compensator（STATCOM） integrated with distribution transformer. The cascaded STATCOM is connected with the system via the primary wingding taps. Then, the compensation principle was proposed. The primary winding current distribution after the compensation current injection was also analyzed. Based on the law of the primary winding currents distribution, a suitable connection point voltage level could be selected. This paper proposed an improved command current detection method and adopted a passivity-based control method to track command current, which would improve the robustness of the control system. Both simulation and experimental results have verified the effectiveness of proposed system.