A power-transmission collection line is connected to each wind turbine of a wind farm and then connected to the incoming switchgear at the low-voltage side of the booster station at a certain distance.Therefore,the gr...A power-transmission collection line is connected to each wind turbine of a wind farm and then connected to the incoming switchgear at the low-voltage side of the booster station at a certain distance.Therefore,the grouping of the wind turbines in the wind farm determines the layout of the lines and affects the line impedance.The line structure and composition of the wind farm are analyzed,and the relationship between the impedance of the collection line and reactive power generated by the wind turbine at low-voltage ride through is derived.We conclude that the smaller the equivalent impedance of the wind farm collection line structure is,the greater the reactive power at the wind farm collection line point is.In addition,the economic aspect of the collection line needs to be considered in the design.The economic aspect and impedance values have contrasting characteristics.Therefore,according to the condition of minimum impedance and optimized economic aspect,an optimization model of a wind-farm collector-circuit structure is proposed.The optimal structure of the wind farm collector circuit is calculated using the Monte Carlo method,and the theoretical analysis is verified by simulation.展开更多
该文基于双馈风电机组(doubly-fed induction generator,DFIG),在电网电压对称骤升下,对电网电压与转子电流之间的暂态过程进行详细的理论推导,提出一种有效抑制转子过电流的控制策略,并针对网侧变换器传统控制方法作出相应的改进。在...该文基于双馈风电机组(doubly-fed induction generator,DFIG),在电网电压对称骤升下,对电网电压与转子电流之间的暂态过程进行详细的理论推导,提出一种有效抑制转子过电流的控制策略,并针对网侧变换器传统控制方法作出相应的改进。在不增加任何硬件设备的情况下,转子侧和网侧分别附加转子电流抑制(rotor current suppression,RCS)和外环电网电压控制(grid voltage suppression,GVS)措施,并给出详细的控制框图。该控制方法不仅可以减少Crowbar装置频繁动作致使转子侧变换器快速短接的问题,而且充分发挥风电机组自身的动态无功支撑能力,保证风电机组在电网电压故障骤升期间不脱网运行,有效提高双馈风力发电机的高电压穿越(high voltage ride through,HVRT)能力及风电机组运行的可靠性。最后,在PSCAD/EMTDC中对所提出的控制策略进行仿真建模分析,验证了该控制方案的有效性和可行性。展开更多
针对180 MW的风电场在电网电压不对称故障下,对整个风电场群组各电气量造成的影响,提出了将三、单相动态电压恢复器(DVR)串联在风电场35 k V等级上的解决方案。对电网电压不对称时DFIG数学模型的暂态特性进行了理论分析,并且利用DVR对...针对180 MW的风电场在电网电压不对称故障下,对整个风电场群组各电气量造成的影响,提出了将三、单相动态电压恢复器(DVR)串联在风电场35 k V等级上的解决方案。对电网电压不对称时DFIG数学模型的暂态特性进行了理论分析,并且利用DVR对风电场35 k V出口电压进行补偿,可使风电场群组的定子电压、转子电流和直流侧电压恢复至正常状态。采用正弦幅值积分器(SAI)作为电网电压的检测电路为DVR提供触发信号。在MATLAB/Simulink中建立了风电场和DVR仿真模型,仿真结果表明,在电网电压不对称故障时,投入DVR可以有效提升风电场不脱网运行能力。展开更多
基金Supported by Natural Science Foundation of Hunan Province of China(2019JJ50119)Educational Commission of Hunan Province of China(18C0510)Zhuzhou City Science and Technology Plan(Zhu Ke Fa[2017]No.68)。
文摘A power-transmission collection line is connected to each wind turbine of a wind farm and then connected to the incoming switchgear at the low-voltage side of the booster station at a certain distance.Therefore,the grouping of the wind turbines in the wind farm determines the layout of the lines and affects the line impedance.The line structure and composition of the wind farm are analyzed,and the relationship between the impedance of the collection line and reactive power generated by the wind turbine at low-voltage ride through is derived.We conclude that the smaller the equivalent impedance of the wind farm collection line structure is,the greater the reactive power at the wind farm collection line point is.In addition,the economic aspect of the collection line needs to be considered in the design.The economic aspect and impedance values have contrasting characteristics.Therefore,according to the condition of minimum impedance and optimized economic aspect,an optimization model of a wind-farm collector-circuit structure is proposed.The optimal structure of the wind farm collector circuit is calculated using the Monte Carlo method,and the theoretical analysis is verified by simulation.
文摘该文基于双馈风电机组(doubly-fed induction generator,DFIG),在电网电压对称骤升下,对电网电压与转子电流之间的暂态过程进行详细的理论推导,提出一种有效抑制转子过电流的控制策略,并针对网侧变换器传统控制方法作出相应的改进。在不增加任何硬件设备的情况下,转子侧和网侧分别附加转子电流抑制(rotor current suppression,RCS)和外环电网电压控制(grid voltage suppression,GVS)措施,并给出详细的控制框图。该控制方法不仅可以减少Crowbar装置频繁动作致使转子侧变换器快速短接的问题,而且充分发挥风电机组自身的动态无功支撑能力,保证风电机组在电网电压故障骤升期间不脱网运行,有效提高双馈风力发电机的高电压穿越(high voltage ride through,HVRT)能力及风电机组运行的可靠性。最后,在PSCAD/EMTDC中对所提出的控制策略进行仿真建模分析,验证了该控制方案的有效性和可行性。
文摘针对180 MW的风电场在电网电压不对称故障下,对整个风电场群组各电气量造成的影响,提出了将三、单相动态电压恢复器(DVR)串联在风电场35 k V等级上的解决方案。对电网电压不对称时DFIG数学模型的暂态特性进行了理论分析,并且利用DVR对风电场35 k V出口电压进行补偿,可使风电场群组的定子电压、转子电流和直流侧电压恢复至正常状态。采用正弦幅值积分器(SAI)作为电网电压的检测电路为DVR提供触发信号。在MATLAB/Simulink中建立了风电场和DVR仿真模型,仿真结果表明,在电网电压不对称故障时,投入DVR可以有效提升风电场不脱网运行能力。
