低电容CHB型混合动力中压电机调速系统

Low-capacitance CHB-based Medium Voltage Motor Speed Regulation System Supplied by Hybrid Power Sources

针对氢燃料电池大功率电机驱动系统,提出一种以燃料电池为主动力源的轻量化级联H桥(cascadedH-bridge,CHB)型混合动力中压电机调速系统。所提系统由燃料电池/蓄电池/超级电容的混合动力源供电,基于四有源桥(quad activebridge,QAB)与CHB子模块互联的两级变换器(cascaded H-bridges with quad active bridge,CHB-QAB)作为调速变换器。CHB-QAB通过四绕组高频变压器将各子模块进行内部互联,采用单边同步双边移相调制的策略,使得所有子模块呈现开关电容特性,在不依赖复杂控制的前提下,减小子模块电容的容值,提升系统的功率密度。针对三类动力源,采用基于低通滤波(lowpassfilter,LPF)的能量管理策略,保证电机实际运行过程中的有效功率分配,解决燃料电池对电机动态响应缓慢和燃料饥饿现象等问题。最后通过仿真与实验对所提轻量化电机调速系统进行验证。

In this paper,a lightweight cascade H-bridge hybrid medium voltage motor speed regulating system with fuel cell as the main power supply is proposed for hydrogen fuel cell high power motor drive system.The proposed system is powered by a hybrid power source of fuel cell/battery/super-capacitor,and is driven by cascaded H bridges based quad active-bridges(CHB-QAB),which is interconnected with four active bridges and sub-modules.CHB-QAB interconnects each sub-module internally through the four-winding high-frequency transformer,and adopts the method of unilateral synchronous and bilateral phase shift modulation to make all sub-modules present switching capacitance characteristics.Under the premise of not relying on complex control,the capacitance of the sub-module is reduced and the power density of the system is improved.For the three types of power sources,the energy management strategy based on low pass filter(LPF)is adopted to ensure the effective power distribution during the actual operation of the motor,and solve the problems such as slow response of the fuel cell to the motor dynamic response and fuel hunger.Finally,the proposed lightweight motor speed control system is verified by simulation and experiment.