摘要
混合级联直流输电系统适用于远距离、大容量、跨区域、多落点输电,但逆变侧换相换流器(linecommutated converter,LCC)交流母线发生故障时易发生换相失败,严重时甚至发生后续换相失败。为了评估混合级联直流输电系统换相失败抵御能力,首先给出混合级联直流输电系统准稳态模型,提出计及系统直流控制特性的交互作用因子计算方法,进而建立考虑模块化多电平变换器(modularmultilevel convertor,MMC)电气特性的混合级联系统逆变侧等值模型。然后,提出基于电压稳定因子(voltage stability factor,VSF)的混合级联系统换相失败抵御能力评估方法,并推导含有效短路比(effective short circuit ratio,ESCR)指标的换相失败免疫因子解析表达式,从理论角度分析交流系统强度对混合级联系统换相失败抵御能力的影响。最后,在PSCAD/EMTDC上搭建混合级联系统的电磁暂态详细仿真模型,验证交互作用因子计算方法、逆变侧等值模型、换相失败抵御能力评估方法的有效性,仿真结果表明,所提方法最大误差在5%左右。结合仿真,详细分析系统控制方式、逆变侧交流联络线等值耦合阻抗、MMC控制器参数对混合级联系统换相失败抵御能力的影响,为混合级联直流输电系统的安全稳定运行提供技术参考。
The hybrid cascaded HVDC system is suitable for long-distance,high-capacity,inter-regional,and multi-point transmission.However,when a fault occurs in the line commutated converter(LCC)AC bus on the inverter side,commutation failure is prone to happen,and in severe cases,subsequent commutation failures may occur.In order to assess the immunity of the hybrid cascaded HVDC system against commutation failures,this paper first presents the quasi-steady-state model of the hybrid cascaded HVDC system and proposes a calculation method for interaction factors considering the DC control characteristics of the system.Subsequently,an equivalent model of the inverter side considering the electrical characteristics of the modular multilevel convertor(MMC)is established.Then,an evaluation method for the immunity of the hybrid cascaded system against commutation failures based on the voltage stability factor(VSF)is proposed,and an analytical expression for the commutation failure immunity factor including the effective short circuit ratio(ESCR)index is derived.The impact of AC system strength on the immunity of the hybrid cascaded system against commutation failures is theoretically analyzed.Finally,a detailed electromagnetic transient simulation model of the hybrid cascaded system is built on PSCAD/EMTDC to validate the calculation method for interaction factors,the equivalent model of the inverter side,and the evaluation method for commutation failure immunity.The simulation results show that the maximum error of the proposed methods is around 5%.Combined with the simulation,the impact of system control modes,the equivalent coupling impedance of the AC interconnection line on the inverter side,and MMC controller parameters on the immunity of the hybrid cascaded system against commutation failures are analyzed in detail,providing technical references for the safe and stable operation of hybrid cascaded HVDC systems.
作者
王鹤
付禹铭
边竞
李国庆
辛业春
王拓
WANG He;FU Yuming;BIAN Jing;LI Guoqing;XIN Yechun;WANG Tuo(Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology,Ministry of Education(Northeast Electric Power University),Jilin 132012,Jilin Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2024年第20期8009-8023,I0008,共16页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国家自然科学基金项目(52207077)
国家重点研发计划项目(2021YFB2400900)。
关键词
混合级联直流输电系统
换相失败
换相失败免疫因子
系统强度
hybrid cascaded HVDC system
commutation failure
commutation failure immunity index(CFII)
system strength
