飞轮储能系统中双向功率变换器控制策略的分析与研究

Analysis and Research of Back-to-back Converter Control Strategy for Flywheel Energy Storage System

微电网需提供功率缓冲装置,飞轮储能装置可快速调节电能质量,为微电网提供频率、电压支撑。为提高飞轮储能系统的动态响应速度,分析了背靠背变换器的数学模型,以此提出了一种在母线电压平方外环、功率内环的直接功率控制策略基础上,增加功率前馈补偿的控制策略。采用该控制策略可大幅改善由于飞轮储能系统切换状态时电机侧PWM变换器状态突变导致的直流母线电压波动,提高微电网侧PWM变换器的响应速度,从而提高系统的运行效率,改善系统的动态运行性能。分析验证了该控制策略的可行性,并利用仿真与实验进行验证。

The micro-grid requires the power buffer equipment.Flywheel energy storage system(FESS)can adjust the electric power quality to support the frequency and amplitude of voltage in micro-grid quickly.To improve the speed of dynamic response,on the basis of mathematical model of back-to-back converter,a new coordinated control strategy which adopts outer voltage square loop and inner power loop with power feed forward compensation was proposed.The control strategy can improve the performance of the fluctuation of DC-bus voltage,when the FESS changes its operational state.Hence,the control strategy improve the response speed of gird-side PWM converter to guarantee the efficiency and the performance of the FESS.The feasibility of the control strategy was demonstrated,and both the simulation analysis and experimental test were employed to verify this new method.