计及采样扰动抑制的电压源逆变器三矢量无模型预测电流控制方法

Triple-vector Model-free Predictive Current Control Method for Voltage Source Inverter With Sampling Disturbance Suppression

针对传统电压源逆变器无模型预测电流控制(model-free predictive current control,MFPCC)方法存在电流纹波大、电流梯度更新停滞以及预测性能易受采样扰动影响的问题。该文提出一种计及采样扰动的三矢量MFPCC方法。在一个控制周期应用3个基本矢量,并根据价值函数计算矢量作用时间,降低了输出电流纹波;其次,通过建立不同矢量作用下的电流梯度方程组,实现电流梯度数据的实时更新,消除了停滞现象;再次,分析采样扰动对MFPCC的影响,采用扩张状态观测器估计采样扰动以补偿预测电流控制,抑制其对输出电流的影响。最后,通过仿真和实验,对所提方法的有效性进行了验证。

Conventional model-free predictive current control(MFPCC)method applied to voltage source inverter(VSI)has the problems of large current ripple,stagnation of current gradient updating,and the prediction performance is easily affected by sampling disturbance.A modulated MFPCC with sampling disturbance suppression is proposed in this paper.In this method,three vectors are applied in a control period,and their durations are calculated according to the cost function,which reduces the output current ripples.By establishing current gradient equations under different vectors,all current gradients can be updated in real time to eliminate stagnation.Besides,the adverse effects of sampling disturbance on MFPCC are analyzed,and then the extended state observer is used to estimate the sampling disturbance,so as to realize disturbance suppression.Finally,the proposed MFPCC is validated by a set of simulations and experiments on a built VSI system.