【目的】针对直流故障后并网点电压大幅度骤升致使风电场面临严重的高电压穿越(high voltage ride-through,HVRT)问题,提出计及保护动作时间协调配合的“有功优先平衡-无功动态补偿”恢复机制。【方法】基于双馈风机的双闭环控制函数,...【目的】针对直流故障后并网点电压大幅度骤升致使风电场面临严重的高电压穿越(high voltage ride-through,HVRT)问题,提出计及保护动作时间协调配合的“有功优先平衡-无功动态补偿”恢复机制。【方法】基于双馈风机的双闭环控制函数,揭示了转子侧变流器无功响应速度优于网侧变流器的动态特性,在减载模式下,提出考虑有功无功协调恢复的风电场HVRT策略。【结果】通过平衡有功功率与无功功率动态补偿,实现了故障期间电压稳定与能量平衡的双重目标。仿真结果表明,该策略可有效抑制暂态过电压风险,提升风电场HVRT能力。【结论】所提策略通过有功-无功协同调控机制,有效破解了高电压穿越过程中系统功率失衡与设备安全运行的矛盾,为含大规模风电的电力系统暂态电压稳定控制提供了新思路。展开更多
This paper is concerned with power reduction control which is used to avoid DC over-voltage for multiterminal HVDC transmission of offshore wind power.Voltages and frequencies of offshore AC wind farm networks are use...This paper is concerned with power reduction control which is used to avoid DC over-voltage for multiterminal HVDC transmission of offshore wind power.Voltages and frequencies of offshore AC wind farm networks are used for transmitting control signals for the power reduction control.These methods do not require fast communication.Power reduction sharing among the offshore wind farms using the different control signals is analysed.The control systems are also compared against the DC chopper method to prevent a DC overvoltage.Simulation and experiments are carried out to evaluate the control systems.展开更多
文摘【目的】针对直流故障后并网点电压大幅度骤升致使风电场面临严重的高电压穿越(high voltage ride-through,HVRT)问题,提出计及保护动作时间协调配合的“有功优先平衡-无功动态补偿”恢复机制。【方法】基于双馈风机的双闭环控制函数,揭示了转子侧变流器无功响应速度优于网侧变流器的动态特性,在减载模式下,提出考虑有功无功协调恢复的风电场HVRT策略。【结果】通过平衡有功功率与无功功率动态补偿,实现了故障期间电压稳定与能量平衡的双重目标。仿真结果表明,该策略可有效抑制暂态过电压风险,提升风电场HVRT能力。【结论】所提策略通过有功-无功协同调控机制,有效破解了高电压穿越过程中系统功率失衡与设备安全运行的矛盾,为含大规模风电的电力系统暂态电压稳定控制提供了新思路。
文摘为了解决双馈风电机组(doubly-fed induction generator wind power generation system,DFIG-WPGS)在连接点电网电压发生跌落故障时的转子过电流、改善DFIG-WPGS的故障穿越(fault-ride-through,FRT)性能等问题,提出了应用于DFIG-WPGS的可变阻尼器(based on variable damper,BVD)的控制方法。该控制方法采用基于虚拟撬棒电阻电感的负反馈控制,在DFIG转子侧引入的虚拟撬棒电阻与故障时电网电压跌落程度相关,且虚拟撬棒电阻的取值控制在合理的取值范围之内;BVD控制方法通过在DFIG转子电流控制环引入阻尼器,限制故障状态下DFIG的转子过电流,且对故障过程中的转子电流进行有效控制。连接点电网电压发生深度跌落故障时DFIG-WPGS的FRT仿真结果显示:在连接点电网电压深度跌落故障发生时刻,BVD控制方法的交流励磁电源直流侧电压的泵升幅度比矢量控制方法的更小,BVD控制方法的DFIG转子过电流幅值更小,而且故障期间转子电流的幅值比矢量控制方法的更大,更利于DFIG的功率控制;实验结果进一步验证了BVD控制方法的有效性。在改善DFIGWPGS的FRT性能过程中,基于可变阻尼器的控制方法不仅可以有效抑制交流励磁电源的直流侧过电压、抑制DFIG转子过电流,而且可以有效控制故障过程中DFIG的输出功率,该方法在风电场具有一定的工程实践使用价值。
基金supported by the Research Councils UK,through the HubNet consortium,www.hubnet.org.uk(grant number:EP/I01363611)the Top and Tail Transformation programme,(grant number:EP/I031707/1)+1 种基金supported by the People Programme(Marie Curie Actions)of the European Union's Seventh Framework Programme FP7/2007-20131(grant number:317221,project title MEDOW)supported by the Joint Research Fund for Overseas Chinese,Hong Kong,and Macao Scientists of the National Natural Science Foundation of China(grant number:51128701).
文摘This paper is concerned with power reduction control which is used to avoid DC over-voltage for multiterminal HVDC transmission of offshore wind power.Voltages and frequencies of offshore AC wind farm networks are used for transmitting control signals for the power reduction control.These methods do not require fast communication.Power reduction sharing among the offshore wind farms using the different control signals is analysed.The control systems are also compared against the DC chopper method to prevent a DC overvoltage.Simulation and experiments are carried out to evaluate the control systems.
