Research On Micro Power Grid Inverter Current Control Robust Compensator

The world energy crisis prompted the people to the study of new energy, the concept of micro grid also arises at the historic moment. As the core component of micro power grid, grid inverter’s output current control has always been the hot spot of the scientific research. For the model errors during its modeling process and its working process is easily influenced by uncertainty factors such as real-time interference. By establishing the model of the inverter current control, we collected the current input and output signals during the step process. In the MATLAB – IDENT toolbox, estimating the system model until its optimal matching achieves more than 98.5%. Adopt the method of robust model matching(RMM), combined with the typical robust control structure, using the estimated model instead of the original control model, on the basis of synchronous rotating dq coordinate control structure, a robust compensator is studied. Considering the practical engineering application of delay caused by switching devices and sampling time, the robust compensator design includes two cases: with time delay and without time delay. Regarding white noise as the equivalent disturbance, respectively applied to the original control structure and the attached robust compensator control structure. After attaching the robust compensator, the anti-interference ability of the micro inverter current control system has improved significantly. Finally, the robust compensator with time delay is attached to the grid inverter simulation model. Simulation results show that, through attaching a robust compensator to improve the robustness of the system is feasible and effective.