基于光储协同的改进型低压穿越控制策略  

Improved low-voltage ride-through control strategy based on photo-storage synergy

作　　者：戴志辉[1] 王文卓 张元波[2] 柳梅元 DAI Zhihui;WANG Wenzhuo;ZHANG Yuanbo;LIU Meiyuan(Hebei Key Laboratory of Distributed Energy Storage and Microgrid,North China Electric Power University,Baoding 071003,China;State Grid Baoding Electric Power Supply Company,Baoding 071003,China)

机构地区：[1]华北电力大学河北省分布式储能与微网重点实验室,河北保定071003 [2]国网保定供电公司,河北保定071003

出　　处：《电机与控制学报》2024年第8期41-49,共9页Electric Machines and Control

基　　金：国家自然科学基金(51877084)。

摘　　要：针对光伏发电系统低压穿越过程中传统控制策略引起的逆变器直流电压泵升,以及储能装置参与协调过程中存在的调节被动和响应滞后问题,提出一种基于光储协同的改进型低压穿越控制策略。首先,揭示不平衡功率在逆变器直流侧堆积是电压泵升的关键原因;其次,以并网点电压支撑与不平衡功率抑制为双重目标,构建逆变器参考电流自适应生成模块,通过优化逆变器低压穿越期间的电流指令抑制不平衡功率的产生。在此基础上,设置直接功率控制的超级电容储能,使其依据光伏与逆变器输出的实时功率差值主动协同消纳超出抑制能力的不平衡功率。仿真结果表明,改进型低压穿越控制策略在保证并网点电压支撑的前提下,通过分级调控获得更快的响应和调节速度,有效解决了逆变器直流侧电压升高问题。To address issues of the DC-side voltage pumping of the converter caused by the traditional control strategy in the process of the low-voltage ride-through(LVRT)of photovoltaic system,as well as the problem of passive regulation and hysteretic response in the coordination process of energy storage devices,an improved LVRT control strategy based on photo-storage synergy was proposed.Initially,the key reason for the voltage pumping was revealed,that is,the accumulation of unbalanced power on the DCside of the converter.Subsequently,an adaptive generation module of reference current was constructed in converter with the dual goals of voltage support at the grid-connected point and unbalanced power suppression to suppress the generation of unbalanced power by optimizing the reference current of the converter during LVRT.Based on these,a super-capacitor with direct power control based on the real-time power difference between the photovoltaic and converter outputs was set up to actively and cooperatively absorb unbalanced power beyond the suppression capacity of converter.The simulation results show that on the premise of ensuring the voltage support of the grid-connected point,the improved LVRT control strategy effectively solves the issue of DC-side voltage increasing of the converter with a faster response and adjust speed through hierarchical control.

关 键 词：低压穿越 光储协同 不平衡功率 直流侧电压 超级电容 

分 类 号：TM771[电气工程—电力系统及自动化]