非理想电网电压下基于谐波功率注入方法的三相并网型变换器的控制

Control of Three-phase Grid Connected Converter Based on Harmonic Power Injection Method Under the Non-ideal Grid Voltage Conditions

在诸如不对称、含有谐波等非理想状况的电网电压下,常规的三相并网型变换器的控制策略将很难取得满意的效果。针对这一问题,基于"电流正弦化且平均单位功率因数为零"及非理想电网电压下的功率流的唯一对应关系,推导出了针对3种控制目标的功率流方程。通过谐波功率注入的方法,可实现3种控制目标的变换器控制。为了提高系统的抵抗模型和参数不确定扰动,设计了线性自抗扰控制器。实验表明所提方法具有结构简单、低谐波等优点。

Under the non-ideal grid voltage conditions, which are distorted or unbalanced grid voltages, the conventional control strategy for three-phase grid connected converter would not be able to obtain satisfactory results. Therefore, based on the relationship between the power flows under non-ideal voltage conditions and the ideal ＂average unit power factor with sinusoidal currents＂, the power flow equations for the three control targets are deduced respectively in this paper. This paper achieves three control targets by harmonic power injection method respectively. Finally, a linear active disturbance rejection control（LADRC） is designed to improve the system＇s performance. Experiments show that the proposed methods have the advantages of simple structure, low harmonics etc.