基于三相变流系统的级联改进自抗扰控制策略

Control Strategy of Cascade Improved Active Disturbance Rejection Based on Three Phase Converter System

针对LCL型变流系统存在的谐波谐振现象和系统稳定运行问题,提出一种基于级联改进自抗扰的变流器控制策略。首先,建立三相LCL型变流器在dq坐标系下的数学模型;然后,在线性自抗扰控制(LADRC)策略基础上引入观测器解耦设计方法,形成改进自抗扰控制策略,提升系统对谐波谐振现象的抵抗能力;最后,形成改进自抗扰和传统自抗扰相结合的双闭环控制策略,并搭建仿真模型进行验证。仿真结果表明,相较于传统三阶自抗扰和比例积分控制,级联改进自抗扰控制下的系统具备更佳的谐波谐振抑制效果与稳定能力。

In the light of harmonic resonance and stable operation of LCL converter system,a control strategy of converter based on cascade improved active disturbance rejection is proposed.Firstly,the mathematical model of three-phase LCL converter in dq coordinate system is established;Then,based on the linear ADRC strategy,the observer decoupling design method is introduced to form an improved ADRC strategy to enhance the resistance of the system to harmonic resonance;Finally,a double closed-loop control strategy combining improved active disturbance rejection and traditional active disturbance rejection is formed,and simulation model is built to verify.The results show that the system under the cascade improved active disturbance rejection control has better harmonic resonance suppression effect and stability ability compared with the traditional third-order active disturbance rejection and proportional integral control.