基于变分模态分解的低电压电能扰动抑制系统设计

Design of low voltage electric energy disturbance suppression system based on variational mode decomposition

低电压造成的扰动问题会直接影响供电系统正常运行,为了保证居民的用电质量,基于变分模态分解设计了一种新的低电压电能扰动抑制系统。硬件部分由网侧电流互感器、状态反馈控制器、状态观测器、光伏并网逆变器四部分组成,通过网侧电流互感器监测电流数据,利用状态观测器得到电流数据,并传输给状态反馈控制器,由状态反馈控制器反馈给控制系统,光伏并网逆变器则起到保护电流稳定电压的作用。软件部分由低电压电能扰动因子提取程序与低电压电能扰动抑制程序组成,在得到电流数据后,由低电压电能扰动因子提取程序结合变分模态分解来对扰动因子进行提取,判定扰动因子,应用低电压电能扰动抑制程序对电能扰动进行抑制,解决低电压电能扰动问题。实验结果表明,电能扰动故障发生时刻设计系统抑制时间仅为0.05 s,故障清除时刻抑制时间仅为0.02 s,具有很好的抑制能力。

The disturbance caused by low voltage will directly affect the normal operation of power supply system.In order to ensure the power quality of residents,a new low voltage electric energy disturbance suppression system is designed based on variational mode decomposition.The hardware part consists of grid side current transformer,state feedback controller,state observer and photovoltaic grid connected inverter.The current data is monitored through the grid side current transformer,the current data is obtained by the state observer and transmitted to the state feedback controller,which is fed back to the control system,and the photovoltaic grid connected inverter plays the role of protecting current and stabilizing voltage.The software part consists of low voltage electric energy disturbance factor extraction program and low voltage electric energy disturbance suppression program.After obtaining the current data,the low voltage electric energy disturbance factor extraction program combined with variational mode decomposition extracts the disturbance factor,determines the disturbance factor,and uses the low voltage electric energy disturbance suppression program to suppress the electric energy disturbance and solve the problem of low voltage electric energy disturbance.The experimental results show that the designed system suppression time at the time of power disturbance fault is only 0.05 s,and the suppression time at the time of fault clearing is only 0.02 s,which has good suppression ability.