考虑直流偏置抑制的单相逆变器改进控制方法

A Modified Control Method of Single-Phase Inverter Considering DC Bias Suppression

为了提升逆变器的控制性能,常采用电压、电流双闭环控制策略。首先分析了用比例控制器构建电感电流控制内环的机理及参数设计,详细讨论了基于准比例积分谐振(proportional integral resonant,PIR)控制的电压外环数学模型和控制器设计方法,给出了双环控制系统的稳定性分析。其次,分析了双环控制无法抑制逆变输出直流偏置的原因,并设计了直流偏置检测电路和抑制策略,以减弱直流偏置对逆变器负载造成的不良影响。最后以10 kW单相逆变器为例,对提出的控制策略和设计方法进行了仿真和实验验证,结果证明了所提控制方案的正确性。

In order to improve the control performance of inverter,voltage and current double closed loop control strategy is often used.Firstly,the mechanism and parameter design of the inductor current control inner loop with the proportional controller are analyzed.The mathematical model of the voltage outer loop based on the quasi proportional integral resonance(PIR)control and the controller design method are discussed in detail.The stability analysis of the dual loop control system is given.Secondly,the reason why the dual loop control cannot suppress the inverter output DC bias is analyzed,and the DC bias detection circuit and suppression strategy are designed to reduce the negative impact of DC bias on the inverter load.Finally,taking a 10 kW single-phase inverter as an example,the proposed control strategy and design method are verified by simulation and experiment,and the results show that the proposed control scheme is correct.