不平衡和非线性负载条件下柔性多状态开关控制技术研究

配电网中连接在两条或多条馈线间的电力电子变流器统称为柔性多状态开关,可作为理想的补偿装置,用来补偿频率和大小变化的谐波、负序和无功。文中建立了不平衡和非线性负载条件下柔性多状态开关的数学模型,根据不平衡系统的控制目标,确定以瞬时无功功率理论为基础的参考电流检测方法,变流器的输出电流采用PI控制器进行调节,从而达到补偿负载电流中的谐波、负序和无功电流,实现电能质量改善。在MATLAB/Simulink环境下,建立了不平衡和非线性负载条件下三端口柔性多状态开关系统的仿真模型,研究结果表明了所采用的方法能够有效地补偿不平衡负载电流中的谐波、负序和无功电流,并表现出了良好的动态性能。

Research on control technology of Flexible Multi-state Switch with unbalanced and nonlinear loads

Flexible multi-state switch (FMSS) is defined as a power electronic converter connected two or more feeders in distribution network. It can compensate the harmonics, negative sequence and reactive power of varying frequency and size. It is an ideal compensation device. In this paper, the mathematical model of flexible multi-state switch under unbalanced nonlinear load condition is established. According to the control target of the system, a reference current detection method based on instantaneous reactive power theory is determined, and the output current of the converter is controlled by PI regulator. It compensates for harmful currents such as negative sequence and harmonic current in the load current to improve power quality. In this paper, a simulation model of three-port flexible multi-state switching system under unbalanced and non-linear load condition is built in Matlab/simulink environment. The research results show that the method used in this paper can effectively compensate the harmful currents such as harmonics and negative sequence of unbalanced systems, and shows good dynamic performance.