基于扩张状态观测器的混合式配电变压器直流母线电压控制

混合式配电变压器能够有效抑制电网谐波和稳定负载侧电压,在配电网末端具有重要意义.针对负载变化、电网电压波动或三相不平衡等情况下,混合式配电变压器直流母线电压不稳定导致的谐波补偿、维持负载电压稳定功能出现的问题,提出一种基于非线性扩张状态观测器的直流母线电压控制策略,将观测出的总扰动通过前馈的方式进行补偿,以提高直流母线电压的稳定性.同时,通过频域分析了所设计扩张状态观测器和电压控制器的稳定性.最后,在MATLAB/Simulink仿真与实验中,与比例-积分控制进行对比,证明了所设计控制器的响应速度更快,稳定性更好.

DC-link Voltage Control of Hybrid Distribution Transformer Based on Extended State Observer

Hybrid distribution transformer (HDT) can effectively suppress the power grid harmonics and stabilize the load voltage, which is of great significance at the end of the distribution network. In the case of load change, power grid voltage fluctuation or three-phase unbalance, the functions of harmonic compensation and maintenance of load voltage stability have problems, which are caused by the bus voltage instability on the DC side of the hybrid distribution transformer. This paper proposes a DC-link voltage control strategy based on the extended state observer (ESO), in which the total observed disturbance is compensated by feedforward to improve the stability of the DC-link voltage. At the same time, the stability of the designed ESO and voltage controller is analyzed in the frequency domain. Finally, in the simulation based on MATLAB/Simulink and the experiment, compared with the proportional-integral (PI) control, the designed controller is proved to have a faster response speed and better stability.