基于超级电容储能型MMC的控制策略

Control Strategy for MMC Based on Super-Capacitor Energy Storage

新能源并网以及冲击性负荷接入易引发电网功率波动,会对邻近发电机组及电力系统的安全稳定构成威胁,为此提出一种基于超级电容器储能型模块化多电平变换器(modular multilevel converter,MMC)的分布式储能系统,利用双向DC/DC变换器控制储能系统的充放电过程,并给出相应参数设计原则。采用了基于双闭环PI调节和移相PWM调制技术的控制策略,控制超级电容能量均衡和MMC级联子模块电容电压稳定,引入能量管理机制控制MMC和DC/DC变换器的协同运行,实现了对中、高压系统中冲击性有功变化率的实时补偿。搭建了Matlab/Simulink模型,仿真结果验证了该装置及控制策略的有效性。

In order to resolve the problems of the rapid variation of power system’s active power caused by grid-integrated renewable energy and pulsed loads,which will threaten the stability of adjacent generator units and power systems,a distributed energy storage system is proposed based on the modular multilevel converter(MMC)integrated with super-capacitor energy storage.The bidirectional DC/DC converters are used to control the charge and discharge process of the energy storage system,and the design principles for relevant parameters are provided.The control strategy based on dual-closed-loop PI regulator and the phase shifted PWM technology is used to control the balance of super-capacitor energy and the capacitor voltage stability of the MMC submodules.The energy management mechanism is introduced to control the collaborative operation of the MMC and the DC/DC converters,subsequently realizing the real-time compensation for pulsed active power variation in medium-and high-voltage systems.The simulation results with Matlab/Simulink platform have verified the effectiveness of the proposed device and control strategy.