摘要
针对低频工况下模块化多电平换流器(MMC)子模块电容电压幅值大幅波动问题,提出1种储能型MMC低频均压混合控制策略,将高频注入与储能型MMC超级电容相结合以有效抑制子模块电容电压的波动。首先分析了MMC低频工况下子模块电容电压波动的原因;其次阐述了高频注入和储能型MMC2种抑制低频工况下子模块电容电压的方法;然后提出储能型MMC低频均压混合控制策略,并对其环流进行公式推导。该方法相对于高频注入方法可减小桥臂电流及环流,减少器件电流应力及系统损耗,且相对于储能型MMC方法对超级电容的容值要求降低。最后,通过Matlab/Simulink对储能MMC低频均压混合控制策略进行仿真,验证了所提控制策略的有效性。
Aiming at the large fluctuation of capacitor voltage amplitude of conventional MMC submodule,the low-frequency equalization switching control strategy is proposed for energy storage MMC,which comprehensively uses the high-frequency injection control method and the energy storage MMC control method to solve the problem of capacitor voltage fluctuation of submodules.Firstly,the cause of submodule voltage fluctuation in low frequency MMC is analyzed,and then the two methods of suppressing the capacity of the submodules at low frequencies of high frequency injection and energy storage MMC are described,and then the hybrid control strategy of low-frequency voltage equalization of the energy storage MMC is proposed,and the formula of the circulation current is derived.Compared with high frequency injection,it can decrease the current and cycle of bridge arm,reduce the current stress and system loss of the device,and reduce the capacitance requirements of the supercapacitor compared with the energy storage MMC method.Finally,Matlab/Simulink is used to simulate the low-frequency equalization hybrid control strategy of energy storage MMC,and the effectiveness of the proposed control strategy is verified.
作者
孙浩
徐友
赵涛
王春霖
李桂璞
SUN Hao;XU You;ZHAO Tao;Wang Chunlin;LI Guipu(Nanjing Institute of Technology,Nanjing 211167,China)
出处
《智慧电力》
北大核心
2024年第5期8-15,共8页
Smart Power
基金
国家自然科学基金资助项目(62203211)
江苏省研究生科研与实践创新计划(SJCX23_1200)。
关键词
模块化多电平换流器
低频控制
子模块均压控制
环流控制
modular multilevel converter
low frequency control
submodule voltage equalization control
circulation control
