应急微电网中柴储移动电源的协调及均衡控制策略

Control Strategy of Coordination and Equalization for Diesel Generator and Energy Storage System in Emergency Microgrid

配电网发生停电事故时,可组建应急微电网来应急供应电力。由于应急微电网存在临时建立、通信条件差、工况多变及电源车频繁插拔等问题,提出了应急微电网中柴储移动电源的协调及均衡控制策略,同时将储能与柴油发电机作为主电源供电。所提控制在一次下垂控制与二次频率及电压恢复控制的基础上加入均衡控制,并基于不同时间尺度解耦。其中,柴油发电机的均衡控制通过反馈频率控制信号来修正稳定运行点,以补偿调速器测量误差实现出力均衡;储能的均衡控制根据荷电状态偏差动态调节下垂斜率,以实现荷电状态的均衡。所提控制策略不依赖于中央控制器,有利于应急供电的迅速开展。最后,仿真验证了控制策略的可行性与有效性。

The emergency microgrid can provide emergency power supply to the distribution networks when large-area blackout occurs.But the emergency microgrid is temporarily established,with poor communication conditions,changeable working conditions and frequently plugged and unplugged mobile emergency power sources.The coordination and equalization control strategy for the emergency microgrid is proposed,in which energy storage systems and diesel generators are used as the main power supply.Besides the primary droop control and the secondary control for frequency and voltage recovery,the control strategy adds the auxiliary equalization control based on multiple time scales.The equalization control of diesel generators can adjust the stable operation point based on the feedback frequency control signal in order to correct the speed measurement error and equalize the output of each power source.And the equalization control of energy storage systems can realize state of charge(SOC)balance by dynamically adjusting the droop slope based on the deviation of SOC.The control strategy does not rely on central controller of microgrid to facilitate quick emergency power supply.Finally,simulation results verify the feasibility and effectiveness of the proposed control strategy.