高压直流(high voltage direct current,HVDC)输电技术相对于高压交流(high voltage alternating current,HVAC)输电技术具有线路损耗低、输电走廊占地少、不存在交流电网同步问题等突出优势,特别适用于大容量、长距离、高效率的电能输...高压直流(high voltage direct current,HVDC)输电技术相对于高压交流(high voltage alternating current,HVAC)输电技术具有线路损耗低、输电走廊占地少、不存在交流电网同步问题等突出优势,特别适用于大容量、长距离、高效率的电能输送场合.相较于传统的电网换相换流器(line commutated converter,LCC)和以模块化多电平换流器(modular multi-level converter,MMC)为典型代表的电压源型换流器(voltage source converter,VSC),主动换相换流器(actively commutated converter,ACC)具有电路拓扑简单、功率因数可控、不存在换相失败风险、具备黑启动的能力、直流侧无需配置储能电容等优点,在高压直流输电领域尤其是海上风电汇集等场合有广泛的应用前景.本文提出了一种大陆端和离岸端换流站均选用ACC作为换流器的海上风电场背靠背高压直流输电系统,大陆端换流站采用开关频率为50 Hz的高功率因数运行的工作模式,离岸端换流器选取脉冲宽度调制(pulse width module,PWM)的工作模式,并分别建立了大陆端换流站和离岸端换流站的数学模型,分析了基于ACC的海上风电场高压直流输电系统的黑启动方法和稳态功率传输特性,并提出了一种大陆端换流站采用直流电流控制、离岸端换流站选取交流侧电压控制的控制策略.在PSCAD/EMTDC中搭建了500 kV/1000MW的基于ACC的海上风电场背靠背高压直流输电系统仿真模型,仿真结果验证了本文理论分析以及所提出控制策略的正确性和有效性.展开更多
This paper proposes a novel AC filter system for a line commutated converter high voltage DC(LCC-HVDC)transmission system.Through the coordination of the hybrid active power filters(APF)and the existing reactive compe...This paper proposes a novel AC filter system for a line commutated converter high voltage DC(LCC-HVDC)transmission system.Through the coordination of the hybrid active power filters(APF)and the existing reactive compensation devices,the proposed filter system can not only enhance the suppression performance for LCC-HVDC harmonics,but also optimize the AC yard layout with reduced reactive power subbanks,reducing the cost of HVDC projects.The novel filter system adopts a serial passive resonance topology obtained by careful comparison of different APFs.A proper control scheme is then designed integrating the control strategy of the APF and impedance characteristics of the HVDC system,which is able to realize harmonic suppression and dynamic reactive power support simultaneously.In addition,a novel self-adaption digital low-pass filter algorithm is presented,which is used in the APF harmonic detecting step,enhancing both high precision and fast dynamic response.On the basis of a real HVDC project,the advantages of proposed filter system in harmonic suppression,reactive power regulation,and sub-banks reduction are simulated and demonstrated.展开更多
介绍一种基于有源换相换流器ACC(active commutated converter)的高压直流HVDC(high voltage direct current)输电系统,分析有源换相换流器在两相旋转坐标系下的数学模型,提出了一种含附加虚拟项的基于比例谐振PR(proportional resonant...介绍一种基于有源换相换流器ACC(active commutated converter)的高压直流HVDC(high voltage direct current)输电系统,分析有源换相换流器在两相旋转坐标系下的数学模型,提出了一种含附加虚拟项的基于比例谐振PR(proportional resonant)控制器的控制策略,并对控制器参数进行了设计,实现了负序电网电流的抑制和换流器的单位功率因数运行。最后,在PSCAD/EMTDC中搭建仿真模型,仿真结果验证了所提出的交流故障穿越策略的正确性和有效性。展开更多
文摘采用自关断功率半导体器件的电流源型主动换相换流器(actively commutated converter,ACC)具有有功与无功功率可解耦、不存在换相失败、无需大量储能电容等特点,在高压直流输电领域具有较好的应用前景。该文针对适用于高压直流输电(high voltage direct current,HVDC)的ACC功率半导体器件及其均压方法、电路拓扑、调制方法、功率特性、控制策略、故障及保护方法等进行调研和分析。结合具体实例,将ACC与现有HVDC的2种换流器,即电网换相换流器(line commutated converter,LCC)和模块化多电平换流器(modular multilevel converter,MMC)进行对比分析。同时,对ACC的潜在应用、存在的问题以及发展的方向进行总结和归纳。
基金This work was supported in part by the National Natural Science Foundation of China(U1766210,51625702)Science and Technology Program of SGCC.
文摘This paper proposes a novel AC filter system for a line commutated converter high voltage DC(LCC-HVDC)transmission system.Through the coordination of the hybrid active power filters(APF)and the existing reactive compensation devices,the proposed filter system can not only enhance the suppression performance for LCC-HVDC harmonics,but also optimize the AC yard layout with reduced reactive power subbanks,reducing the cost of HVDC projects.The novel filter system adopts a serial passive resonance topology obtained by careful comparison of different APFs.A proper control scheme is then designed integrating the control strategy of the APF and impedance characteristics of the HVDC system,which is able to realize harmonic suppression and dynamic reactive power support simultaneously.In addition,a novel self-adaption digital low-pass filter algorithm is presented,which is used in the APF harmonic detecting step,enhancing both high precision and fast dynamic response.On the basis of a real HVDC project,the advantages of proposed filter system in harmonic suppression,reactive power regulation,and sub-banks reduction are simulated and demonstrated.
文摘介绍一种基于有源换相换流器ACC(active commutated converter)的高压直流HVDC(high voltage direct current)输电系统,分析有源换相换流器在两相旋转坐标系下的数学模型,提出了一种含附加虚拟项的基于比例谐振PR(proportional resonant)控制器的控制策略,并对控制器参数进行了设计,实现了负序电网电流的抑制和换流器的单位功率因数运行。最后,在PSCAD/EMTDC中搭建仿真模型,仿真结果验证了所提出的交流故障穿越策略的正确性和有效性。
