新型模糊逻辑二级电压控制器

A NOVEL FUZZY LOGIC SECONDARY VOLTAGE CONTROLLER

设计了一种新型的基于极坐标二值模糊逻辑规则的模糊逻辑二级电压控制器。该控制器有效地将模糊逻辑规则和二次电压控制相结合 :将引导节点的电压偏差及其微分作为模糊逻辑控制规则的前项输入 ,与规则作用后 ,推理出相应的电压控制信号 ,然后引入比例积分器 ,得到区域无功控制信号 ,通过发电机的励磁控制 ,实现对引导节点电压的控制。该控制器通过引入控制发电机的参与因子 ,实现了区域内各控制发电机之间的相互协调和补充。以 New England39节点系统为例进行仿真计算 ,结果表明 :所设计的二级电压控制器在系统发生电压扰动的期间 ,能够从区域电压稳定的角度出发 ,调整各级电压控制器的电压参考值从而调整其无功出力 ,为系统提供所需的电压支持 ,使得系统的负荷电压水平维持在较好的状态 ,提高了系统的电压稳定性。它比常规 PID二级电压控制器具有更好的控制性能。

A novel fuzzy logic secondary voltage controller based on polar fuzzy logic rule is designed in this paper. The controller effectively combines fuzzy logic rule with secondary voltage control: The voltage error of pilot buses and its differential are the inputs of fuzzy logic block. The inputs go through the reasoning of fuzzy rules and generate the voltage control signal, which is transferred to a PI block, where the signal of area reactive power control is available. The controller adjusts voltage level of the pilot bus through the excitation control with the rules of fuzzy logic. By using participant factor the generators' reactive power output in an area can be coordinated and support each other. Numerical simulation is carried out on the New England 39 bus system. Simulation of small disturbance on load shows that the fuzzy logic controller can restore the voltage level more rapidly than conventional PID controller. When load increases slowly, the testing system with fuzzy logic secondary voltage controller has a better voltage level and a larger steady voltage stability margin than those with conventional secondary voltage controller. Finally the simulation results on grounded fault show that the critical clearing time is prolonged under the effect of fuzzy logic secondary voltage controller.