Parameter adaptive virtual DC generator control strategy for DC microgrid
In DC microgrid, the sudden change of load power will cause the bus voltage to fluctuate greatly, which will lead to system instability in serious cases. Aiming at this problem, a parameter adaptive control strategy of virtual DC motor based on differential compensation is proposed, taking energy storage parallel converter as the research object. The proposed strategy feeds back the output voltage deviation of the energy storage converter to the differential compensation coefficient, so that the compensation coefficient can adjust the compensation coefficient in real time following the load fluctuation, effectively reducing the impact of power fluctuation on the system stability and improving the system dynamic performance. In the parallel system, the parallel power distribution can be realized according to the ratio of armature resistance in the control of each converter. The small signal model of the system is established, and the influence of the key control parameters on the system stability is analyzed by using the Bode diagram and the impedance ratio criterion. Finally, MATLAB/Simulink simulation and StarSim HIL experimental platform verify the effectiveness of the proposed parameter adaptive control strategy for the new virtual DC generator.