面向新能源灵活接入的多功能动态电压恢复器及其优化控制研究

Multi-function Dynamic Voltage Restorer and Its Optimal Control for Flexibly Access of New Energy Sources

随着新能源和非线性、不对称负载的大量接入,电网中电能质量问题日益突出。针对现有电能质量调节装置功能单一、利用率低等问题,提出一种面向新能源灵活接入的多功能动态电压恢复器(multi-functiondynamicvoltage restorer,MF-DVR)。基于矢量控制原理,MF-DVR可同时实现新能源消纳和电网电能质量调节功能。首先介绍了MF-DVR拓扑结构和矢量控制原理,通过数学推导证明,控制负载电压相位角可同时改变MF-DVR补偿电压和输出功率;分析了MF-DVR的工作特性,通过数学推导和矢量图分析得出,串联电容可有效降低逆变器输出电压的幅值;其次,根据负载电压相位角的不同取值,对MF-DVR工作模态进行详细分析;提出双电压外环控制,有效解决了串联电容电压直流偏置问题;最后,通过MATLAB/Simulink仿真和RT-LAB硬件在环实验,验证了所提拓扑结构及控制方法的正确性和可行性。

With a large number of new energy and non-linear,asymmetric load access,the power quality problems in a power grid have become increasingly prominent.Aiming at the problems of single function and low utilization of the existing power quality regulation devices,this paper proposes a multi-function dynamic voltage restorer(MF-DVR)for the flexibly access of the new energy sources.The MF-DVR is able to realize both the functions of new energy consumption and power quality regulation based on the vector control principle.Firstly,the topology structure and the vector control principle of the MF-DVR are introduced.The mathematical derivation proves that the compensation voltage and the output power of the MF-DVR can be controlled by changing the phase angle of the load voltage.The working characteristics of the MF-DVR are analyzed,and the results of the mathematical derivation and the vector diagram analysis show that the amplitude of the inverter output voltage can be effectively reduced by the capacitors in series.Secondly,according to the different values of the load voltage phase angle,the working mode of the MF-DVR is analyzed in detail.The double voltage outer loop control is proposed to effectively solve the DC bias problem of series capacitor voltage.Finally,the correctness and feasibility of the proposed topology and control method are verified by the MATLAB/Simulink simulation and the RT-LAB hardware in the loop experiment.