半桥三电平双有源桥不对称均压控制策略  

Asymmetric voltage equalization control strategy ofhalf-bridge three-level dual active bridge

作　　者：王志刚 王后生 张青杰 吴金利[1,2,3] 葛伟美 WANG Zhigang;WANG Housheng;ZHANG Qingjie;WU Jinli;GE Weimei(State Key Laboratory of Smart Grid Protection and Control,Nanjing 211106,China;NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211106,China;NARI Technology Co.,Ltd.,Nanjing 211106,China)

机构地区：[1]智能电网保护和运行控制国家重点实验室,江苏南京211106 [2]南瑞集团(国网电力科学研究院)有限公司,江苏南京211106 [3]国电南瑞科技股份有限公司,江苏南京211106

出　　处：《电力工程技术》2022年第6期221-229,共9页Electric Power Engineering Technology

基　　金：国家电网有限公司总部科技项目(SGNXDK00DWJS2200035)。

摘　　要：半桥三电平双有源桥(HBTL-DAB)电路工作时必须解决三电平侧上下直流母线电容均压问题,在传统对称控制模式中,可通过微调占空比的方法,实现带载情况下的电容电压均衡控制。然而在空载情况下,对称控制模式难以从控制策略上实现上下直流母线电容电压的均衡调节。针对该问题,文中提出一种针对HBTL-DAB电路的不对称控制方法,首先从理论上分析对称模式不能均压的原因,进而根据不对称方法计算空载时上下直流母线电容分别在正负半周期内传输的能量偏差。通过调节该能量偏差实现上下直流母线电容电压的均衡控制,并同时指出影响电压均衡控制效果的主要因素。最后通过仿真,对所述不对称控制方法在多种工况下的运行情况进行验证。结果表明,无论是外部持续存在不平衡因素的工况、只存在初始不平衡因素的工况,还是内部存在脉冲误差的工况,不对称控制方法都能实现空载和带载时的电压均衡控制。To make sure the half-bridge three-level dual active bridge(HBTL-DAB)circuit works correctly,the problem of capacitor voltage equalization between the upper and lower direct current(DC)buses on the three-level side must be solved.In the traditional symmetrical control mode,the capacitor voltage equalization control under load can be achieved by fine-tuning the duty cycle.However,in the case of no-load,the symmetrical control mode is difficult to realize the balance adjustment of the upper and lower DC bus capacitor voltages from the control strategy.Therefore,in view of the above problem,an asymmetric control method for the HBTL-DAB circuit is proposed.Firstly,the reason why the symmetrical mode cannot be equalized is theoretically analyzed.And then according to the asymmetric method,energy deviation on the upper and lower DC bus capacitor between positive and negative half cycles under no-load conditions is calculated.The capacitor voltage equalization control is achieved by adjusting the energy deviation,and the main factors affecting the effect of voltage balance control are also pointed out.Finally,the asymmetric control method is verified under various working conditions by simulation.The results show that no matter in condition of existing external continuous unbalance factors,or external initial unbalance factors,or internal pulse error factors,voltage balance adjustment is achieved by the asymmetric control method under no-load and loaded conditions.

关 键 词：半桥三电平(HBTL) 双有源桥(DAB) 对称控制 不对称控制 中点电位平衡 电压均衡 

分 类 号：TM46[电气工程—电器]