基于级联多电平换流器的链式储能系统控制策略及直流侧谐波抑制策略研究  

Research on strategy for control and restraining harmonics of cascaded h-bridge converter storage

作　　者：祁琦[1] 盛晓东[1] 王宇[1] QI Qi;SHENG Xiaodong;WANG Yu(NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211102

出　　处：《电气应用》2023年第7期91-96,共6页Electrotechnical Application

基　　金：内蒙古自治区科技重大专项2021ZD0039适应高比例新能源消纳的储能电站协调运行控制关键技术研究与示范应用。

摘　　要：储能技术是构建以新能源为主体的新型电力系统的关键技术。基于级联多电平换流器的链式储能系统采用与交流电网直连的方式,若干功率模块级联实现交流输出电压的提升。该方案延续了储能设备响应速度快、效率高的特点,同时相较于传统的升压式储能损耗更小、谐波含量更低,尤其适用于大容量储能电站的应用。然而,链式储能系统的拓扑结构决定了其功率模块直流侧有较大的电流二次谐波,该谐波直接注入电池系统将导致电池系统高频率充放电,严重影响电池的使用寿命,降低储能系统的可靠性;国内外现有研究中,功率模块可以通过无源滤波设备与电池系统进行连接,一定程度上降低了电池侧的电流脉动。研究了基于级联多电平换流器的链式储能系统的控制策略,针对其功率模块直流电流二次谐波含量高的问题,提出了一种利用DC/DC变换器抑制电流谐波的策略,该策略可大幅降低功率模块直流电流二次谐波含量,适用于中压大容量级联多电平链式储能系统。最终,通过仿真和实验验证了所提控制策略的可行性和有效性。Energy storage is the key support for building a new power system with new energy as the main body.Cascaded H-bridge converter energy storage directly connects to power grid,several power modules are cascaded to increase the voltage of the AC side.Cascaded H-bridge converter energy storage continues the advantages of fast response speed and high efficiency,while it also has the advantages of less losses and low harmonic content.It is especially suitable for the application of large capacity energy storage.However,the DC side of the power module in cascaded H-bridge converter energy storage has a large second harmonic current,which directly injected into the battery system will result in high-frequency charging and discharging of the battery system.The second harmonic current seriously affect the service life of the battery and reduce the reliability of the energy storage system.Therefore,the control strategy of cascaded H-bridge converter energy storage is Studied.Aiming at the problem of high second harmonic content of battery current,a strategy of DC/DC converter for restraining harmonics is proposed.This strategy can be widely used in cascaded H-bridge converter energy storage.Finally,the feasibility and effectiveness of the proposed control strategy are verified by simulation and experiment.

关 键 词：储能技术 链式储能 控制策略 谐波抑制 

分 类 号：TM91[电气工程—电力电子与电力传动]