摘要
风光水打捆经电网换相换流器高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)外送系统中,风光水配比不同会影响系统的功率传输能力。文章首先建立风光水打捆直流外送系统的稳态数学模型和状态空间模型,然后提出综合考虑稳态运行约束条件和小信号稳定性约束条件的系统功率传输能力计算方法及流程,掌握不同功率水平下系统稳定运行区域及边界的变化特征,最终得到不同水电出力下的直流外送系统功率传输范围、特定传输功率下所允许的水电出力最小值、风光配比与小信号稳定性的定量关系。通过该方法定量评估风光水配比不同时直流外送系统的功率传输能力,从而优化选取风光水配比。结果表明,水电出力较小时,系统传输功率上限受小信号稳定性制约,下限受电压偏移约束制约;水电出力较大时,系统传输功率上限受LCC-HVDC安全运行约束制约,下限受逆变侧电压偏移、系统潮流约束制约;在功率运行点不变时,风光配比平衡工况系统更加稳定。最后,通过PSCAD/EMTDC下的电磁暂态仿真,验证上述功率传输能力理论计算的正确性。
Different wind-photovoltaic(PV)-hydro ratio conditions will affect the power transmission capacity of wind-PV-hydro-bundled transmission system delivered by line commutated converter based high voltage direct current system(LCC-HVDC).First,the steady-state mathematical model and state space model of wind-PV-hydro-bundled HVDC transmission system are established.Then,considering steady-state operation constraints and small signal stability constraint,the calculation method and process of system power transmission capacity are proposed,and the variation features of stable operation area and boundary under different power levels are mastered.Finally,the power transmission range under different hydropower output,the minimum allowable hydropower output under specific transmission power and the quantitative relationship between wind-PV power ratio and small signal stability are obtained.The power transmission capacity with different wind-PV-hydro ratio conditions is evaluated quantitatively by using this method to optimize the selection of wind-PV-hydro ratio.The results show that when the hydropower output is small,the upper limit of system transmission power is restricted by small signal stability,and the lower limit is restricted by the voltage offset.When the hydropower output is large,the upper limit of system transmission power is restricted by LCC-HVDC safe operation constraints,and the lower limit is restricted by voltage offset of the inverter side and system power flow.When the power operating point is unchanged,the system is more stable under the balanced wind-PV ratio condition.Finally,the PSCAD/EMTDC simulation results verify the correctness of theoretical calculations of power transmission capacity.
作者
刘晓颖
郭春义
迟永宁
LIU Xiaoying;GUO Chunyi;CHI Yongning(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2024年第13期5051-5062,I0003,共13页
Proceedings of the CSEE
基金
国家电网有限公司科技项目“4000米高海拔下接入弱交流系统的分址建设特高压直流设计关键技术研究”(5200-202256077A-1-1-ZN)。
关键词
风光水打捆直流外送系统
功率传输能力
稳态运行约束条件
小信号稳定性约束条件
风光水配比
wind-PV-hydro-bundled LCC-HVDC transmission system
power transmission capacity
steady-state operation constraints
small signal stability constraint
wind-PV-hydro ratio
