摘要
提出了一种基于转子多阶串联动态电阻电路与直流卸荷电路的双馈风力感应发电机(DFIG)低/高电压穿越(LVRT/HVRT)保护方案。在分析该方案拓扑及原理的基础上,推导故障后转子电流解析表达式,给出了保护阻值参数的实用整定方法,结合电网电压跌落和骤升故障及故障不同阶段机组性能的要求,制定了保护的投切控制策略。结果表明,该方案不仅能更好地抑制电网电压跌落/骤升故障初始阶段机组转子过电流、直流侧过压及电磁转矩振荡峰值,兼顾提升机组抵御电网电压跌落和骤升故障的能力,而且能够降低故障持续阶段保护投切引起的暂态振荡冲击,有利于延长机组整体寿命。最后通过实验验证了所提改进控制策略及保护方案的可行性。
To enhance low voltage ride through/high voltage ride through(LVRT/HVRT)capabilities of doubly fed induction generator(DFIG),a protection scheme is proposed by integrating a rotor multi-step series dynamic resistor with a DC-link chopper.Topology and basic principle of the scheme is analyzed.After deducing the analytical expression of the DFIG rotor current under grid voltage fault,the resistance setting is executed using the grahing method.The switching control strategy is given considering the requirements from voltage swell/sag flaults and different stages.The results show that it can limit peak fault rotor over-current,DC-link over-voltage and electromagnetic torque overshoot more efficiently during the initial stage under voltage sag and swell fault and thus enhance the capabilities of the unit to resist voltage sag and swell fault.And the fault transient oscillations caused by protection activation are also can be re-duced effectively which can prolong the lifetime of the unit.Finally,the feasibility of the proposed improved control strategy is verified by experiments.Compared with the traditional control strategy,the proposed improved control strategy can significantly enhance the reactive power control ability to meet the requirements of the power grid guidelines,which is helpful to improve the transient voltage level of the connected power grid when the fault occurs.
作者
姚维平
赵越
郑卫洪
杨帮宇
YAO Wei-ping;ZHAO Yue;ZHENG Wei-hong;YANG Bang-yu(State Grid Tianjin Electric Power Company,Tianjin 300010,China;不详)
出处
《电力电子技术》
CSCD
北大核心
2022年第10期13-16,28,共5页
Power Electronics
基金
国网天津市电力公司科技项目(KJ21-1-3)
关键词
双馈风力感应发电机
低电压穿越
高电压穿越
doubly fed induction generator
low voltage ride through
high volatge ride through
