微电网中储能运行模式自发切换的对策研究

Research on Countermeasures for Spontaneously Mode Switching of Energy Storage System in Microgrid

十三五期间,新能源建设由集中式光伏电站向分布式光伏全面推进,构建含储能的微电网成为消纳分布式光伏的有效运行方式。依托浙江某分布式能源示范工程,通过储能系统主、从PCS分散控制及顺控同期并网策略实现光储微电网的并/离网平滑切换。但在切换试验时发现,由于各分系统之间的通讯延时与内部计算延时,微电网并网后储能主PCS充放电运行模式自发切换,电流骤增并触发限功率运行。通过建立储能等效模型与理论分析,提出避免限功率运行及减小大电流充电时间的对策,并对工程进行回路改造与软件升级后再次并网。试验结果验证所提对策可有效提高此分布式能源示范工程运行安全性与经济性,亦对今后实际微电网工程具有借鉴意义与指导作用。

During the 13th five-year plan period,the construction of new energy has been promoted from centralized photovoltaic power stations to distributed photovoltaics.Thus,microgrid with energy storage system is becoming an effective way to consume distributed photovoltaics.In a distributed energy demonstration project in Zhejiang province,the seamless switch of photovoltaic-storage microgrid operation mode was realized by decentralized control of master-slave PCS in energy storage system and sequential synchronous grid connection strategy.However,in the project testing,there are communication delays and calculation delays between actual engineering subsystems,which result in the main PCS mode switching spontaneously after grid connected.Then,the current surges and triggers the energy storage system power-limited operation.By establishing the energy storage equivalent model and conducting theoretical analysis,the countermeasures were proposed to avoid power-limited operation and shorten the charging time of energy storage system.Grid-connection was retested after the circuit modification and the software update.The test results verify that the proposed countermeasures not only effectively improve the safety and economy of this project,but also have great reference significance as well as guiding role for actual microgrid project in the future.