基于变功率与直流电压组合控制的混合微电网协调控制

Coordinated Controlof Hybrid Micro-grid Based on Variable Power Control and DC Voltage Control

当前混合微电网中双向AC/DC变换器主要采用U/f控制,由这种控制策略以及交流子微电网的运行情况确定直流子微电网的输入输出功率,这对直流子微电网产生很大的影响。针对这种问题,将直流子微电网作为一个波动性微电源与负荷,双向AC/DC变换器采用直流电压控制,根据直流子微电网的运行情况,确定双向AC/DC变换器功率的流向与大小。为了更好地保证直流电压控制策略的实现,直流子微电网采用变功率控制策略,由此提出了基于变功率控制与直流电压控制的混合微电网的协调控制策略。最后在Simulink中建立上述控制策略的模型,并进行仿真分析。仿真结果证明:上述控制策略能够实现交直流混合微电网的稳定运行,以及混合微电网的平滑切换。

The bidirectional AC/DC converter in current hybrid micro-grid mainly adopts U/f control mode.And the input and output powers of the DC sub-micro-grid are determined by this kind of control strategy and operation of the AC sub-micro-grid,which may greatly affect the DC sub-micro-grid.Therefore,this paper regards the DC sub-micro-grid as fluctuant micro power source and load,and uses DC voltage control for the bidirectional AC/DC converter.Meanwhile,according to operation of the DC sub-micro-grid,it determines power flow and size of the converter.In order to better ensure realization of the DC voltage control strategy,it suggests to adopt the variable power control strategy for the DC sub-micro-grid and proposes a coordinated control strategy for the hybrid micro-grid based on variable power control and DC voltage control.By establishing a model of the strategy in Simulink,it makes a simulating analysis.The simulation results indicate the proposed strategy can realize stable operation of the AC/DC hybrid micro-grid and smooth switching of the micro-grid.