Voltage-balancing Control Strategy of Cascade Converter Supplying Power to Microgrid
The cascaded converter topology with series on the DC side and parallel on the AC side is currently a better choice for the converter of the transmission system in the scenario of medium and low voltage and small capacity.Ai-ming at the problem of capacitor voltage balancing on the DC side of the cascaded converter,we proposed a cascaded converter control strategy with voltage-balancing function that can supply power to the microgrid with 100％/high per-centage of new energy in this paper.It includes voltage/frequency control with self voltage-balancing and optimal droop control with self voltage-balancing.The large signal stability of the proposed control strategy is analyzed according to the mixed potential function theory,and the parameter design requirements of the controller are given.Compared with the traditional voltage equalizing strategy,the strategy proposed in this paper can participate in the frequency control/regu-lation of the system,and the optimal droop control with self voltage-balancing can also avoid the data communication between sub-modules.The simulation results show that the proposed strategy can realize the voltage sharing function under steady-state and various fault conditions,and can also participate in the frequency modulation of microgrid to en-sure that the system frequency does not exceed the safety threshold.
cascade convertervoltage balancingdroop controlfrequency modulationmixed potential function
万方数据
维普
