电网不平衡下并网逆变器的矢量比例积分控制  

Vector Proportional Integral Control of Grid-connected Inverter under Unbalanced Grid

作　　者：王素娥[1] 王子婷 郝鹏飞[1] WANG Su’e;WANG Ziting;HAO Pengfei(College of Electrical and Control Engineering,Shaanxi University of Science and Technology,Xi’an 710021,China)

机构地区：[1]陕西科技大学电气与控制工程学院,西安710021

出　　处：《电源学报》2023年第1期99-106,共8页Journal of Power Supply

基　　金：陕西省科技厅资助项目(2018XNCG-G-12);西安市科技计划资助项目(2020KJRC0001)。

摘　　要：当电网电压发生不平衡故障时,逆变器的输出电流会发生畸变。通过分析电网电压不平衡下逆变器的网侧数学模型,提出了一种基于矢量比例积分VPI(vector proportional integral)控制器的PI-VPI(proportional integralvector proportional integral)控制策略。通过系统开环、闭环的Bode图对PI-VPI控制器性能进行分析,发现相比于传统的比例谐振PR(proportional resonance)控制策略,PI-VPI控制器可确保闭环电流控制达到谐振频率处期望的0°相位响应,提高电流闭环控制的稳定性与控制精度。设计了PI-VPI控制器参数。仿真与实验结果表明,该方法能有效抑制电网电压不平衡引起的输出电流畸变。The distortion of output current from an inverter will occur under unbalanced grid voltage faults.Through the analysis of the mathematical model of a grid-side inverter under unbalanced grid voltage,a proportional integral-vector proportional integral(PI-VPI)control strategy based on a VPI controller is proposed.Based on the performance analysis of the PI-VPI controller by means of the open-loop and closed-loop Bode diagrams of the system,it is found that compared with the traditional proportional resonance(PR)control strategy,the PI-VPI controller can ensure that the closedloop current control reaches the desired 0°phase response at the resonance frequency,thus improving the stability and control accuracy of the current closed-loop control.The parameters of the PI-VPI controller are designed,and simulation and experimental results prove that the proposed method can effectively suppress the output current distortion caused by the unbalanced grid voltage.

关 键 词：不平衡电网 PI-VPI控制器 并网逆变器 直接电流控制 

分 类 号：TM46[电气工程—电器]