考虑原动机特性的下垂控制策略研究

Research on droop control strategy associated with characteristics of prime movers

由于原动机功率响应速度存在明显差异,微电网内部不同原动机特性的微电源难以根据经典的下垂控制承担负荷,因此提出了一种改进的下垂策略。在有功/频率下垂基础上,该策略分别通过动态改变下垂增益以及增加功率微分量的手段调节变流器交流侧的功率响应,达到协调控制微电网内储能和微型燃气轮机的目的。仿真结果显示在负荷突增时,该策略可以使储能承担大部分突变负荷。随着储能下垂增益的调节,至稳定后储能和微型燃气轮机能够根据经典下垂控制策略分担稳态负荷。因此在突增负荷工况下,该策略能够防止微型燃气轮机变流器直流母线电压崩溃,适宜不同原动机特性的微电源进行协调控制。

There are significant differences on power response of prime movers, and micro sources with different prime movers cannot share load by classic droop control in micro grid. In response to this challenge, an enhanced droop con trol method is proposed. Based on Pf droop, power response of converters is regulated by dynamic adjustment of droop gain and adoption of active power derivative, so cooperative control of energy storage and micro turbine in micro grid can be achieved by the proposed method. The simulation results show that energy storage shares most of abrupt change at sudden loadup condition. With the adjustment of droop gain, energy storage and micro turbine can share constant load by classic droop control strategy in steady state. The proposed scheme is suit for cooperative control of micro sources with different prime movers and collapse of DC link voltage for micro turbine converters can be avoided at sud den loadup condition.