基于复合虚拟阻抗的混合储能系统功率分频协调与谐波电流抑制策略  

Power Division Coordination and Harmonic Current Suppression Strategy for Hybrid Energy Storage System Based on Composite Virtual Impedance

作　　者：杨苓 黄俊滔 朱涤凡 YANG Ling;HUANG Juntao;ZHU Difan(School of Automation,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学自动化学院,广州510006

出　　处：《高电压技术》2023年第5期2017-2028,共12页High Voltage Engineering

基　　金：国家自然科学基金(52107185);广东省基础与应用基础研究基金(2019A1515110768)。

摘　　要：混合储能系统在传统下垂控制下不能根据蓄电池和超级电容各自的储能特点和动态响应进行功率合理分配,同时单相逆变器负荷的存在导致前级变换器和输入源产生二次谐波电流,这将缩短系统的使用寿命,破坏系统稳定运行。针对以上问题,该文提出一种基于复合虚拟阻抗的功率分频协调与低频谐波电流抑制策略。在复合虚拟阻抗作用下,系统等效输出阻抗在低频段和高频段分别由蓄电池侧和超级电容侧阻抗主导,此时蓄电池提供系统功率波动的低频分量,抑制直流母线电压波动以稳定系统能量供需平衡,超级电容快速吸收系统功率波动的高频分量,提高系统的动态响应。在此基础上分析了复合虚拟阻抗使电感支路在二倍频时呈现高阻抗,非二倍频时呈现低阻抗,从而抑制二次谐波电流。最后,通过实验验证所提方法的有效性。Under the traditional droop control,the hybrid energy storage system can not reasonably distribute the power according to the energy storage characteristics and dynamic response of the battery and supercapacitor.At the same time,the existence of single-phase inverter load leads to the generation of second harmonic current in the front-stage converter and the input source,which will shorten the service life of the system and destroy the stable operation of the system.To solve the above problems,a power division coordination and low-frequency harmonic current suppression strategy based on composite virtual impedance is proposed in this paper.Under the action of composite virtual impedance,the low-frequency and high-frequency equivalent output impedance of the system are dominated by the impedance of the battery side and the supercapacitor side,respectively.At this time,the battery provides the low-frequency component of the system power fluctuation and suppresses the DC bus voltage fluctuation to stabilize the system energy supply and demand balance.The supercapacitor quickly absorbs the high-frequency component of system power fluctuation and improves the dynamic response of the system.On this basis,it is analyzed that the composite virtual impedance enables the inductance branch to show a high impedance at the double output frequency,and to show a low impedance outside the double output frequency,so as to suppress the second harmonic current.Finally,the effectiveness of the proposed method is verified by experiments.

关 键 词：直流微电网 混合储能系统 单相逆变器负荷 复合虚拟阻抗 功率分频协调 低频谐波电流抑制 

分 类 号：TM912[电气工程—电力电子与电力传动] TM53