弱电网矿区下构网型储能控制技术研究

Research on Grid⁃forming Energy Storage Control Technology in Weak Network Mining Area

矿区通常地处偏远、电力基础设施薄弱,随着可再生能源发电的占比提高,导致矿区电网呈现弱电网特性。文中提出了面向矿区复杂电网工况的储能控制技术,实现了矿区电网稳定性的提升。首先,文中研究了储能在矿区电网中供电结构及工作模式。其次,针对VSG控制技术在孤岛应急运行模式和弱电网并网运行模式下的运行特性进行分析。再次,针对弱电网下的VSG并网稳定性缺失的问题,提出了改善弱电网下电压稳定性的构网型VSG控制策略,并提出了一种预同步切换策略减少矿区电网工况切换状态过程中的暂态冲击。最后,对所提方法进行仿真案例分析,仿真结果表明所提控制策略能够有效提升矿区电网的稳定性,实现了并离网切换的平滑过度和负荷冲击下的储能瞬时响应,提升了弱电网矿区下的储能系统动态特性。

Mining areas are usually located in remote areas with weak power infrastructure.With the increase of pro⁃portion of renewable energy generation,the mining area’s power grid exhibits weak grid characteristics.In this pa⁃per,the energy storage control technology for complex power grid conditions in the mining areas is proposed and the improvement of stability of the power grid in the mining areas is achieved.Firstly,the power supply structure and working mode of energy storage in the mining area power grid is studied in this paper.Secondly,the operational char⁃acteristics of VSG control technology in island emergency operation mode and weak current grid connected operation mode are analyzed.Moreover,in response to the lack of stability in VSG grid connection under weak current net⁃works,a grid⁃forming VSG control strategy is proposed to improve voltage stability under weak current networks.A presynchronization switching policy is also proposed to reduce transient impacts during the switching process of the mining area power grid conditions.Finally,a simulation case analysis is conducted on the proposed method,and the simulation results show that the proposed control strategy can effectively improve the stability of power grid of the mining area,achieving smooth transition between parallel and off grid switching,and instantaneous energy storage re⁃sponse under load impact,thereby improving the dynamic characteristics of the energy storage system in weak cur⁃rent mining areas.