The high-speed simulation of large-scale offshore wind farms(OWFs) preserving the internal machine information has become a huge challenge due to the large wind turbine(WT) count and microsecond-range time step. Hence...The high-speed simulation of large-scale offshore wind farms(OWFs) preserving the internal machine information has become a huge challenge due to the large wind turbine(WT) count and microsecond-range time step. Hence, it is undoable to investigate the internal node information of the OWF in the electro-magnetic transient(EMT) programs. To fill this gap,this paper presents an equivalent modeling method for largescale OWF, whose accuracy and efficiency are guaranteed by integrating the individual devices of permanent magnet synchronous generator(PMSG) based WT. The node-elimination algorithm is used while the internal machine information is recursively updated. Unlike the existing aggregation methods, the developed EMT model can reflect the characteristics of each WT under different wind speeds and WT parameters without modifying the codes. The access to each WT controller is preserved so that the time-varying dynamics of all the WTs could be simulated. Comparisons of the proposed model with the detailed model in PSCAD/EMTDC have shown very high precision and high efficiency. The proposed modeling procedures can be used as reference for other types of WTs once the structures and parameters are given.展开更多
Wind-farm-side modular multilevel converters(WFMMCs) used in modular multilevel converter based highvoltage direct current(MMC-HVDC) transmission systems must be able to control the AC grid voltage in offshore wind fa...Wind-farm-side modular multilevel converters(WFMMCs) used in modular multilevel converter based highvoltage direct current(MMC-HVDC) transmission systems must be able to control the AC grid voltage in offshore wind farms. Different AC voltage control strategies can significantly affect the dynamic characteristics of WFMMCs. However, existing studies have not provided a general methodology of controller parameter design, and few comparative studies have been conducted on control performance under varying operating conditions as well as the effects of different AC voltage control modes(AVCMs) on the stability of MMC-HVDCs with offshore wind farms. This paper provides a controller parameter design method for AVCMs, which is tested in various operating scenarios. Sequence impedance models of offshore wind farms and WFMMCs under different AVCMs are then developed. The effects of AVCMs on the small-signal stability of the interconnected system are then analyzed and compared using the impedance-based method. Finally, case studies are conducted on a practical MMC-HVDC system with offshore wind farms to verify the theoretical analysis.展开更多
基于电压源型变流器的高压柔性直流输电(voltage source converter based HVDC,VSC-HVDC)是海上风电的典型输送方式,大规模海上风电经这种方式集结并接入陆上交流电网,对常规电力系统的影响越来越明显。分析了直驱式海上风电VSC-HVDC在...基于电压源型变流器的高压柔性直流输电(voltage source converter based HVDC,VSC-HVDC)是海上风电的典型输送方式,大规模海上风电经这种方式集结并接入陆上交流电网,对常规电力系统的影响越来越明显。分析了直驱式海上风电VSC-HVDC在主动调频控制下,对临近同步发电机组功角稳定性的影响。搭建了含风电VSC-HVDC的两机等值电力系统模型,通过理论推导和等面积法,分析了在发生负荷突变和短路故障时,考虑调频控制的风电VSCHVDC对临近同步发电机组功角摇摆的影响规律,最后通过在PSCAD/EMTDC软件上搭建的仿真模型验证了理论分析的有效性。展开更多
基金supported by the National Natural Science Foundation of China (No. 52277094)Science and Technology Project of China Huaneng Group Co.,Ltd.(No. HNKJ20-H88)。
文摘The high-speed simulation of large-scale offshore wind farms(OWFs) preserving the internal machine information has become a huge challenge due to the large wind turbine(WT) count and microsecond-range time step. Hence, it is undoable to investigate the internal node information of the OWF in the electro-magnetic transient(EMT) programs. To fill this gap,this paper presents an equivalent modeling method for largescale OWF, whose accuracy and efficiency are guaranteed by integrating the individual devices of permanent magnet synchronous generator(PMSG) based WT. The node-elimination algorithm is used while the internal machine information is recursively updated. Unlike the existing aggregation methods, the developed EMT model can reflect the characteristics of each WT under different wind speeds and WT parameters without modifying the codes. The access to each WT controller is preserved so that the time-varying dynamics of all the WTs could be simulated. Comparisons of the proposed model with the detailed model in PSCAD/EMTDC have shown very high precision and high efficiency. The proposed modeling procedures can be used as reference for other types of WTs once the structures and parameters are given.
基金supported by the National Natural Science Foundation of China (No. 51907125)。
文摘Wind-farm-side modular multilevel converters(WFMMCs) used in modular multilevel converter based highvoltage direct current(MMC-HVDC) transmission systems must be able to control the AC grid voltage in offshore wind farms. Different AC voltage control strategies can significantly affect the dynamic characteristics of WFMMCs. However, existing studies have not provided a general methodology of controller parameter design, and few comparative studies have been conducted on control performance under varying operating conditions as well as the effects of different AC voltage control modes(AVCMs) on the stability of MMC-HVDCs with offshore wind farms. This paper provides a controller parameter design method for AVCMs, which is tested in various operating scenarios. Sequence impedance models of offshore wind farms and WFMMCs under different AVCMs are then developed. The effects of AVCMs on the small-signal stability of the interconnected system are then analyzed and compared using the impedance-based method. Finally, case studies are conducted on a practical MMC-HVDC system with offshore wind farms to verify the theoretical analysis.
文摘基于电压源型变流器的高压柔性直流输电(voltage source converter based HVDC,VSC-HVDC)是海上风电的典型输送方式,大规模海上风电经这种方式集结并接入陆上交流电网,对常规电力系统的影响越来越明显。分析了直驱式海上风电VSC-HVDC在主动调频控制下,对临近同步发电机组功角稳定性的影响。搭建了含风电VSC-HVDC的两机等值电力系统模型,通过理论推导和等面积法,分析了在发生负荷突变和短路故障时,考虑调频控制的风电VSCHVDC对临近同步发电机组功角摇摆的影响规律,最后通过在PSCAD/EMTDC软件上搭建的仿真模型验证了理论分析的有效性。
