基于超级电容储能型MMC的控制策略

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。

Control Strategy for MMC Based on Super-Capacitor Energy Storage

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 bi-directional 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 sub-modules. 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.