对于风电并网系统,双馈风电机组电网侧电压严重跌落容易在风机转子侧形成峰值涌流,损坏变流设备,并造成风机脱网。因此提出了模型预测转子电流控制(model predictive rotor current control,MP-RCC)与动态电压恢复器(dynamic voltage re...对于风电并网系统,双馈风电机组电网侧电压严重跌落容易在风机转子侧形成峰值涌流,损坏变流设备,并造成风机脱网。因此提出了模型预测转子电流控制(model predictive rotor current control,MP-RCC)与动态电压恢复器(dynamic voltage restorer,DVR)的协调控制策略,以提高双馈风机在故障情况下不脱网运行的能力。首先,根据双馈风电机组的工作原理,建立其预测控制状态空间模型;其次,在双馈风机转子侧施加MP-RCC,从而实现双馈风电机组低电压穿越时转子电流对参考值的迅速跟踪;最后,引入动态电压恢复器,在低电压穿越期间补偿电网压降,维持机端电压,以保证风电机组在MP-RCC控制下稳定运行。通过Matlab/Simulink对所提控制策略进行了仿真验证,结果表明,MP-RCC与DVR的协调策略可以有效应对双馈风电机组的低电压穿越过程,提高双馈风电机组的故障穿越能力。展开更多
双馈风力发电机转子电流模型参考自适应系统(MRAS)的转速估算方法中,由于定、转子电压、电流采样信号的漂移及AD转换的偏差,致使所估计的双馈电机转速幅值中呈现不同程度的交流脉动。针对此问题,提出了在自适应实时调节机构中,采用PI并...双馈风力发电机转子电流模型参考自适应系统(MRAS)的转速估算方法中,由于定、转子电压、电流采样信号的漂移及AD转换的偏差,致使所估计的双馈电机转速幅值中呈现不同程度的交流脉动。针对此问题,提出了在自适应实时调节机构中,采用PI并联比例谐振(PR)控制器共同作用的控制策略。该方法可消除转速估计中角频率和转差频率的交流脉动,实现转速精确估计,提高双馈电机发电质量。基于10 k W的双馈风力发电模拟平台进行了实验研究,通过与PI控制对比验证了PI并联比例谐振控制的优越性。展开更多
Nd-Fe-B-type magnet is exclusively used as a rotor magnet in the traction motor of hybrid electric vehicle(HEV)and electric vehicle(EV),but its overly high operating temperature is a lingering problem attached to the ...Nd-Fe-B-type magnet is exclusively used as a rotor magnet in the traction motor of hybrid electric vehicle(HEV)and electric vehicle(EV),but its overly high operating temperature is a lingering problem attached to the magnet.The major cause of the high operating temperature is eddy current,which is readily generated in the highly conductive metallic magnet under alternating magnetic field from stator ripple.In this article,temperature rise in the Nd-Fe-B-type magnet with varying electrical resistivity under alternating magnetic field is discussed with the intention of highlighting the importance of enhancing the electrical resistivity for reducing the operating temperature of the Nd-Fe-B-type rotor magnet.Temperature rise in the Nd-Fe-B-type magnet(dielectric salt-added die-upset magnet)with high electrical resistivity is noticeably lower compared to the magnet(commercial sintered rotor magnet)with lower electrical resistivity,substantiating the theory that enhancing the electrical resistivity in the rotor magnet is fairly effective for suppressing the over-rise of its operating temperature during operation.Die-upset process is revealed to be particularly pertinent for the fabrication of highly dense salt-added magnet with high electrical resistivity.展开更多
In this study,a novel rotor sleeve for permanent-magnet(PM)machines equipped with fractional-slot concentrated-windings(FSCW)is proposed.With the newly designed rotor sleeve,the rotor eddy-current(EC)losses are signif...In this study,a novel rotor sleeve for permanent-magnet(PM)machines equipped with fractional-slot concentrated-windings(FSCW)is proposed.With the newly designed rotor sleeve,the rotor eddy-current(EC)losses are significantly reduced,and the torque density of the machine is improved.First,the rotor EC losses of a surface-mounted PM machine with the sleeve are analyzed.Meanwhile,the sleeve EC barriers and PM segmentation technologies for the suppression of the rotor EC losses are evaluated.Subsequently,an FSCW PM machine with the newly designed sleeve is proposed and optimized for a given set of specifications.Its electromagnetic and mechanical performances are evaluated by the finite element method(FEM).Finally,three assembling methods are presented and assessed comprehensively in terms of their merits and drawbacks.展开更多
文摘对于风电并网系统,双馈风电机组电网侧电压严重跌落容易在风机转子侧形成峰值涌流,损坏变流设备,并造成风机脱网。因此提出了模型预测转子电流控制(model predictive rotor current control,MP-RCC)与动态电压恢复器(dynamic voltage restorer,DVR)的协调控制策略,以提高双馈风机在故障情况下不脱网运行的能力。首先,根据双馈风电机组的工作原理,建立其预测控制状态空间模型;其次,在双馈风机转子侧施加MP-RCC,从而实现双馈风电机组低电压穿越时转子电流对参考值的迅速跟踪;最后,引入动态电压恢复器,在低电压穿越期间补偿电网压降,维持机端电压,以保证风电机组在MP-RCC控制下稳定运行。通过Matlab/Simulink对所提控制策略进行了仿真验证,结果表明,MP-RCC与DVR的协调策略可以有效应对双馈风电机组的低电压穿越过程,提高双馈风电机组的故障穿越能力。
文摘双馈风力发电机转子电流模型参考自适应系统(MRAS)的转速估算方法中,由于定、转子电压、电流采样信号的漂移及AD转换的偏差,致使所估计的双馈电机转速幅值中呈现不同程度的交流脉动。针对此问题,提出了在自适应实时调节机构中,采用PI并联比例谐振(PR)控制器共同作用的控制策略。该方法可消除转速估计中角频率和转差频率的交流脉动,实现转速精确估计,提高双馈电机发电质量。基于10 k W的双馈风力发电模拟平台进行了实验研究,通过与PI控制对比验证了PI并联比例谐振控制的优越性。
基金financially supported by the Technology Innovation Program from the Ministry of Trade,Industry and Energy(MOTIE,Korea)(No.10080382).
文摘Nd-Fe-B-type magnet is exclusively used as a rotor magnet in the traction motor of hybrid electric vehicle(HEV)and electric vehicle(EV),but its overly high operating temperature is a lingering problem attached to the magnet.The major cause of the high operating temperature is eddy current,which is readily generated in the highly conductive metallic magnet under alternating magnetic field from stator ripple.In this article,temperature rise in the Nd-Fe-B-type magnet with varying electrical resistivity under alternating magnetic field is discussed with the intention of highlighting the importance of enhancing the electrical resistivity for reducing the operating temperature of the Nd-Fe-B-type rotor magnet.Temperature rise in the Nd-Fe-B-type magnet(dielectric salt-added die-upset magnet)with high electrical resistivity is noticeably lower compared to the magnet(commercial sintered rotor magnet)with lower electrical resistivity,substantiating the theory that enhancing the electrical resistivity in the rotor magnet is fairly effective for suppressing the over-rise of its operating temperature during operation.Die-upset process is revealed to be particularly pertinent for the fabrication of highly dense salt-added magnet with high electrical resistivity.
基金Supported by the National Natural Science Foundation of China(51991383)the Natural Science Foundation of Jiangsu Province(BK20171298)+1 种基金the Graduate Scientific Research Innovation Project of Jiangsu Province(KYCX18_2248)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘In this study,a novel rotor sleeve for permanent-magnet(PM)machines equipped with fractional-slot concentrated-windings(FSCW)is proposed.With the newly designed rotor sleeve,the rotor eddy-current(EC)losses are significantly reduced,and the torque density of the machine is improved.First,the rotor EC losses of a surface-mounted PM machine with the sleeve are analyzed.Meanwhile,the sleeve EC barriers and PM segmentation technologies for the suppression of the rotor EC losses are evaluated.Subsequently,an FSCW PM machine with the newly designed sleeve is proposed and optimized for a given set of specifications.Its electromagnetic and mechanical performances are evaluated by the finite element method(FEM).Finally,three assembling methods are presented and assessed comprehensively in terms of their merits and drawbacks.
