基于柔性配电网级联H桥固态变压器电压与功率均衡控制策略  

Research on voltage and power balance control strategy of cascaded H-bridge solid state transformer based on flexible distribution networks

作　　者：卢林煜 王鲁杨 恽东军 许学儒 陈超 LU Linyu;WANG Luyang;YUN Dongjun;XU Xueru;CHEN Chao(College of Electrical Engineering,Shanghai University of Electrical Power,Shanghai 20090,China;Datang Huaibei Power Station,Huaibei 23500,China;Guangdong Power Grid Company Shanwei Power Supply,Shanwei 516600,China;State Grid Chongqing Power Grid Company Dazu District Power Supply,Chongqing 402360,China)

机构地区：[1]上海电力大学电气工程学院,上海200090 [2]大唐淮北发电厂,安徽淮北235000 [3]广东电网有限责任公司汕尾供电局,广东汕尾516600 [4]国网重庆市电力公司大足区供电分公司,重庆402360

出　　处：《电力科学与技术学报》2021年第1期152-159,共8页Journal of Electric Power Science And Technology

基　　金：上海绿色能源并网工程技术研究中心资助(13DZ2251900)。

摘　　要：固态变压器(SST)是能源互联网中配电网的核心设备,对电力网络能量流主动控制。提出一种级联H桥(CHB)型SST的新型电压与功率均衡控制策略,并阐述其作用机理。首先,针对输入级CHB直流侧电压不平衡问题,提出利用有功和无功占空比同时修正的电压与无功均衡控制策略。该方法不但消除了平衡控制器和系统控制器之间的耦合效应,而且CHB各电容电压和无功达到平衡状态。其次,利用输入级有功占空比分量作为隔离级功率均衡控制的反馈量,并对其进行修正以解决因参数差异导致各双有源全桥DC-DC变换器,传递功率不均衡问题。此外,综合分析前后级控制器的协调控制以提高系统的瞬态性能。最后,通过仿真验证了该控制策略的可行性与有效性。Solid State Transformer(SST)is the central equipment of distribution network in Energy Internet,which controls the power flow actively.In this paper,a novel voltage and power balance control strategy for Cascaded H-Bridge(CHB)-type SST is proposed,and the design method and operation mechanism of the control strategy are analyzed.Firstly,in order to solve the problem of unbalanced voltage on the DC side of CHB in the input stage,a voltage and reactive power balance control strategy that utilizes both active and reactive duty cycle modification are proposed.This method not only eliminates the coupling effect between the balance controller and the system controller,but also balances the voltage and reactive power of CHB capacitors.Secondly,the active-duty component of the input stage is taken as the power balance control feedback of the isolation-stage and the correction is made to solve the problem of unbalanced power transferring of the dual active bridge DC-DC converters due to the parameter differences.In addition,the coordination control of the front and rear controller is analyzed to improve the system transient performance.Finally,the feasibility and effectiveness of the control strategy are verified by simulation.

关 键 词：固态变压器 配电网 级联H桥 电压平衡 双有源全桥DC-DC变换器 

分 类 号：TM72[电气工程—电力系统及自动化]