并网变流器的多内模自适应重复控制方法研究OA

The application of grid connected inverters in new energy generation,power quality control and other fields is gradually widespread,but its output harmonic of the grid connected current has a significant impact on power system.The repetitive control is a method to suppress harmonics by introducing harmonic components into the reference waveform and comparing them with error signals in the controller.It is widely used in grid connected converters due to its good tracking performance to periodic disturbances.However,in case of power grid frequency fluctuation,the reasonant frequency of the repetitive control will deviate from the fundamental and harmonic fre-quencies of the actual power grid,which greatly reduces the harmonic suppression ability of the system.Therefore,in this paper a multi-internal model adaptive repetitive control strategy combined with PI is proposed to suppress harmonic interference in grid-connected converters.Firstly,the typical topology and control structure of the used grid connected converter are given and its mathematical model is set up.Then,in view of the shortcomings of the tra-ditional repetitive controller,the correction factor are introduced to enhance the control gain under harmonics and improve the frequency adaptability of the system.Finally,parameters of the proposed control strategy are designed,and the effectiveness of the proposed strategy is verified through simulation and experiments.