考虑SOC自均衡的直流微电网协调控制策略研究

Research on Coordinated Control Strategy of Direct Current Microgrid Considering SOC Self-balance

针对独立运行的直流微电网,提出了一种多模式协调控制策略。首先,针对母线电压受负荷变化影响存在的闪变问题,设计了一种直流微电网多模式切换控制算法,该算法可根据母线电压的变化,实现系统工作模式的自适应切换,达到稳定母线电压的目的;其次,为了避免储能单元(energy storage unit,ESU)过度放电和深度充电,储能系统(energy storage system,ESS)采用改进下垂控制,在充放电过程中,均可使荷电状态(state of charge,SOC)趋于均衡;最后,仿真结果表明所提控制策略在保证SOC快速均衡的前提下,可减小母线电压偏差,维持独立直流微电网的稳定运行,从而验证了所提控制策略的有效性。

A multi-mode coordinated control strategy is proposed for an independently operating direct current microgrid.Firstly,in order to solve the problems such as flashover of bus voltage due to load changes,a multi-mode switching control algorithm for direct current microgrid was designed.The algorithm can realize the adaptive switching of the system’s working mode according to the fluctuation of the bus voltage,it can achieve the purpose of reducing the fluctuation of the bus voltage.Secondly,in order to avoid over discharging and deep charging of the energy storage unit,the energy storage systemadopts improved droop control.During charging and discharging,the state of charge(SOC)can be balanced.Finally,the simulation results show that the control strategy proposed in this paper can reduce the bus voltage deviation and maintain the stable operation of the autonomous direct current microgrid under the premise of ensuring the rapid equilibrium of the SOC,thus verifying the effectiveness of the proposed control strategy.