基于扰动观测器的三相逆变电路改进型模型预测控制

经逆变电路并网的分布式发电系统中,为了解决传统模型预测控制(MPC)在电路参数变化时系统动态响应不佳的问题,在ABC三相坐标下,提出一种基于扰动观测器(DOB)的改进型模型预测控制(AdMPCDOB)方案,对被控电流进行两步预测,同时采用多重比例谐振(PR)调节器作为MPC的前馈补偿,消除预测电流的周期性误差,并提高对特定次谐波的抑制能力。考虑到电路参数变化和不确定扰动对系统造成的影响,采用电感电流扰动观测器对MPC输入信号进行精确观测。理论分析和仿真试验表明,所提改进型控制方案能够有效提高逆变器输出电能质量,降低并网电流总谐波畸变率(THD)。

Advanced Model Predictive Control for ThreePhase InverterCircuit Based on Disturbance Observer

In the distributed generation system connected to the inverter circuit, in order to solve the problem that the system dynamic response of the model predictive control (MPC) was poor when the circuit parameters changed, a method based on ABC threephase coordinates was proposed. This scheme was called advanced MPC with disturbance observer (DOB) (AdMPCDOB). It predicted the controlled current in two steps, and a proportional resonant (PR) regulator was used as the feedforward compensator of the MPC. Compensation could eliminate the periodic error of the predicted current and improve the ability to suppress specific harmonics. Taking into account the influence of circuit parameters and uncertain disturbances on the system, the inductive current DOB was used to accurately observe the MPC input signal. The theoretical analysis and simulation experiments showed that the improved control scheme could effectively improve the output power quality of the inverter and reduce the total harmonic distortion (THD) rate of the gridconnected current.