With an increasing penetration of wind power in the modern electrical grid, the increasing replacement of large conventional synchronous generators by wind power plants will potentially result in deteriorated frequenc...With an increasing penetration of wind power in the modern electrical grid, the increasing replacement of large conventional synchronous generators by wind power plants will potentially result in deteriorated frequency regulation performance due to the reduced system inertia and primary frequency response. A series of challenging issues arise from the aspects of power system planning,operation, control and protection. Therefore, it is valuable to develop variable speed wind turbines(VSWTs) equipped with frequency regulation capabilities that allow them to effectively participate in addressing severe frequency contingencies. This paper provides a comprehensive surveyon frequency regulation methods for VSWTs. It fully describes the concepts, principles and control strategies of prevailing frequency controls of VSWTs, including future development trends. It concludes with a performance comparison of frequency regulation by the four main types of wind power plants.展开更多
Doubly-Fed Induction Generator (DFIG), with vector control applied, is widely used in Variable-Speed Constant- Frequency (VSCF) wind energy generation system and shows good performance in maximum wind energy capture. ...Doubly-Fed Induction Generator (DFIG), with vector control applied, is widely used in Variable-Speed Constant- Frequency (VSCF) wind energy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through (FRT) capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control (IMC) method, was carried out. The validity of the pro- posed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.展开更多
变速变桨距风力发电机组的限功率控制通常采用变桨距控制技术。该方法在高风速时能通过调节桨距角来快速稳定的控制功率输出和风机转速,但在中低风速时,却没有充分利用风力机特性,以优化风机运行工况。该文在综合分析全风速限功率控制...变速变桨距风力发电机组的限功率控制通常采用变桨距控制技术。该方法在高风速时能通过调节桨距角来快速稳定的控制功率输出和风机转速,但在中低风速时,却没有充分利用风力机特性,以优化风机运行工况。该文在综合分析全风速限功率控制特性基础上,提出一种主动变速和桨距角控制相结合的新型限功率控制策略(novel wind power curtailment control,N-WPCC)。理论分析和仿真结果表明,与传统限功率控制相比,N-WPCC优先进行电磁转矩控制,再进行桨距角控制,能有效减少变桨系统的动作频率和动作幅度,提高变桨系统的使用寿命,并能充分利用机组转动惯量,在一定程度上提高发电量。同时,N-WPCC的控制输入为机组输出功率和电机转速,不需要可靠性不高的现场实时测风数据。展开更多
基金supported in part by the National Natural Science Foundation of China (Nos.61428301,61433004 and 61627809)
文摘With an increasing penetration of wind power in the modern electrical grid, the increasing replacement of large conventional synchronous generators by wind power plants will potentially result in deteriorated frequency regulation performance due to the reduced system inertia and primary frequency response. A series of challenging issues arise from the aspects of power system planning,operation, control and protection. Therefore, it is valuable to develop variable speed wind turbines(VSWTs) equipped with frequency regulation capabilities that allow them to effectively participate in addressing severe frequency contingencies. This paper provides a comprehensive surveyon frequency regulation methods for VSWTs. It fully describes the concepts, principles and control strategies of prevailing frequency controls of VSWTs, including future development trends. It concludes with a performance comparison of frequency regulation by the four main types of wind power plants.
基金Project (No.50577056) supported by the National Natural Science Foundation of China
文摘Doubly-Fed Induction Generator (DFIG), with vector control applied, is widely used in Variable-Speed Constant- Frequency (VSCF) wind energy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through (FRT) capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control (IMC) method, was carried out. The validity of the pro- posed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.
文摘变速变桨距风力发电机组的限功率控制通常采用变桨距控制技术。该方法在高风速时能通过调节桨距角来快速稳定的控制功率输出和风机转速,但在中低风速时,却没有充分利用风力机特性,以优化风机运行工况。该文在综合分析全风速限功率控制特性基础上,提出一种主动变速和桨距角控制相结合的新型限功率控制策略(novel wind power curtailment control,N-WPCC)。理论分析和仿真结果表明,与传统限功率控制相比,N-WPCC优先进行电磁转矩控制,再进行桨距角控制,能有效减少变桨系统的动作频率和动作幅度,提高变桨系统的使用寿命,并能充分利用机组转动惯量,在一定程度上提高发电量。同时,N-WPCC的控制输入为机组输出功率和电机转速,不需要可靠性不高的现场实时测风数据。
