光伏直流升压接入系统故障穿越协同控保方法  

A Coordinated Control and Active Protection for PV DC Boosting Integration System During FRT

作　　者：贾科 宣振文 朱正轩 杨哲 毕天姝 刘颖[2] JIA Ke;XUAN Zhenwen;ZHU Zhengxuan;YANG Zhe;BI Tianshu;LIU Ying(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources（North China Electric Power University）,Changping District,Beijing 102206,China;State Grid Power Economic Research Institute,Changping District,Beijing 102211,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]国网北京经济技术研究院,北京市昌平区102211

出　　处：《电网技术》2018年第10期3249-3257,共9页Power System Technology

基　　金：国家重点研发计划基金资助项目(2016YFB0900203);国家自然科学基金项目(51777071,51407067);中央高校基本科研业务费基金资助项目(2016ZZD01);国家电网公司科技项目(5205A0160002)~~

摘　　要：与传统交流汇集式光伏电站相比,光伏直流升压接入系统在故障穿越时存在直流母线电压严重上升且系统自身控制策略影响交流保护动作性能问题。根据光伏阵列P-V曲线的单峰特性设计了适用于光伏直流升压接入系统的无通信协调控制方案,实现了故障穿越期间直流母线电压的稳定控制;同时提出系统低穿控制与保护协同方案,在系统故障穿越期间通过换流器主动向电网施加短窗长谐波扰动,从而为所提基于谐波量测的距离保护构造出清晰的动作边界。PSCAD仿真结果表明,所提控保协同方法在保证系统可靠进行故障穿越的同时,能准确识别系统故障工况,场站侧保护在所施谐波扰动窗长内快速动作,有效避免并网逆变器因网侧保护先行跳闸失去同步电源而产生的暂态冲击。Compared with traditional photovoltaic（PV） power plants, PV DC boosting integration system faces more serious problem of the control and protection during the fault-ride-through（FRT）. In this paper, based on single-peak characteristics of PV arrays, a non-communication coordinated control scheme is designed, applicable to PV boosting integration system. The proposed coordinated control scheme realizes stability control of DC-bus voltage to keep security of whole system during FRT. However, the control strategy of DC system FRT will bring great challenges to AC protections. Thus, this paper proposes a combined strategy of protection and control by actively applying a harmonic disturbance with a narrow window length during the FRT to construct a clear boundary for the harmonic-measured distance protection. Simulation results verify effectiveness of the proposed coordinated control and protection. It shows that the proposed protection can accurately identify fault conditions of the system. And the proposed protection deployed on the interfaced-inverter side can quickly operate within harmonic disturbance, effectively avoiding transient impact due to disconnection from host grid.

关 键 词：光伏 直流升压 故障穿越 协调控制 主动保护 

分 类 号：TM721[电气工程—电力系统及自动化]