摘要
针对均匀低光照下组串式逆变器效率低的问题,提出一种提高组串逆变器并行效率的直流侧开关重构策略。基于一种光伏直流开关拓扑结构对多光伏串和多逆变器的连接进行控制。考虑光伏系统效率和并行开关电气寿命等系统运行指标,控制逆变器运行台数使系统效益指标函数最优。提出防止逆变器功率越限策略,利用最小二乘回归算法预测天气短时间变化范围,确定光伏系统允许的开关重构方案;对比不同时刻其他最佳开关连接方式,选出最终连接方案最小化开关切换次数。最后,利用控制决策决定直流开关重构的最终方案,将提出的策略与常规光伏发电和仅考虑目标函数发电作数据对比,验证该策略的有效性与可行性。
In order to solve the problem of low efficiency of string inverter during uniform and low irradiance conditions,a DC side switch reconfiguration strategy is proposed to improve the parallel efficiency of the string inverter.Based on a photovoltaic(PV)DC switch topology,switches are controlled to form multi-PV groups that can run jointly with multi-inverters.The efficiency of PV system and the electrical life of switches are considered.The number of inverters is controlled to optimize the benefit index function of the PV system.Based on the least-squares regression algorithm,short time range of weather is predicted.The connection methods of the PV system structure are analyzed to prevent power violation of inverters.The best switch connection at different times is compared to determine the best connection scheme.The times of switching is minimized by the scheme.Finally,the final scheme of DC switch reconfiguration is decided by control decision.The proposed strategy is compared with PV generation strategies of consider only objective function and conventional to verify the effectiveness and feasibility of this strategy.
作者
薛世伟
贾清泉
李盼
梁纪峰
耿亮
Xue ShiweiJia Qingquan;Li Pan;Liang Jifeng;Geng Liang(Key Lab of Power Electronics for Energy Conservation and Motor Drive of Hebei Province Yanshan University,Qinhuangdao 066004 China;Electric Power Research Institute of State Grid Hebei Electric Power Supply Co.Ltd,Shijiazhuang 050021 China;Shijiazhuang Power Supply Branch of State Grid Hebei Electric Power Co.Ltd,Shijiazhuang 050021 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2021年第9期1761-1770,共10页
Transactions of China Electrotechnical Society
基金
国家自然科学基金(51877186)
河北省重点研发计划(20314301D)
河北省自然科学基金(E2018203358)资助项目。
关键词
光伏系统
群控系统
多逆变器并联
动态重构
频繁切换
Photovoltaic system
group control system
paralleled multi-inverters
dynamic reconfiguration
frequent switching
作者简介
薛世伟,男,1993年生,博士研究生,研究方向为分布式电源电能质量治理。E-mail:xueshiweihao@163.com;通信作者:贾清泉,男,1970年生,教授,博士生导师,研究方向为电能质量监测与控制、分布式电源与微电网。E-mail:jiaqingquan@sina.com。
