引用本文: | 邓友汉,肖志怀,程远楚,张新龙.基于DBR的交直流复用Crowbar低电压穿越[J].电力自动化设备,2014,34(6): |
| DENG Youhan,XIAO Zhihuai,CHENG Yuanchu,ZHANG Xinlong.AC-DC multiplexing Crowbar LVRT scheme based on DBR[J].Electric Power Automation Equipment,2014,34(6): |
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摘要: |
在深入分析双馈风力机组数学模型的基础上,通过对现有低电压穿越方案的控制策略和效果的研究,提出了基于动态刹车电阻(DBR)的交直流复用Crowbar低电压穿越方案。所述方案有2种工作方式:当电网电压轻度跌落时,运行于直流Crowbar工作方式;当电网电压深度跌落时,运行于交直流复用Crowbar方式。针对2 MW双馈风力发电机组进行了试验,对设计方案进行了验证。研究表明,所述方案对电网电压轻度跌落持续可控;对电网电压深度跌落,利用并联整流桥取代机侧变频器输送转子故障能量至直流母线,规避了跌落瞬间机侧变频器容量不足的缺点,至机侧变频器重启并联整流桥退出,恢复背靠背变频连接。对不同程度电网电压跌落,所述方案均能实现低电压穿越,故障期间无功支撑满足电网导则要求。 |
关键词: 风电 低电压穿越 动态刹车电阻 直流Crowbar 交流Crowbar 无功支撑 |
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基金项目:国家自然科学基金资助项目(51379160) |
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AC-DC multiplexing Crowbar LVRT scheme based on DBR |
DENG Youhan1, XIAO Zhihuai1, CHENG Yuanchu1, ZHANG Xinlong2
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1.School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China;2.Renewable Energy Department of China Electric Power Research Institute,Nanjing 210003,China
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Abstract: |
The mathematical model of DFIG(Doubly Fed Induction Generator) wind generator is analyzed,the control strategy and effect of existing LVRT (Low Voltage Ride Through) schemes are studied,and an AC-DC multiplexing Crowbar LVRT scheme based on DBR (Dynamic Braking Resistance) is proposed,which has two working modes:DC Crowbar mode for mild grid voltage drop and AC-DC multiplexing Crowbar mode for deep grid voltage drop. The test results of a 2 MW DFIG wind generator show that,the wind turbine keeps controllable during mild grid voltage drop,while during deep grid voltage drop,the rectifier is used to replace the GSC(Grid-Side Converter) to transport the fault power of rotor to DC bus for avoiding the defect of insufficient GSC capacity. When GSC restarts successfully,the rectifier quits and the back-to-back con-verter recovers. The proposed scheme realizes LVRT during grid voltage drop,either mild or deep,and meets the requirements of the state grid guidelines for the reactive power support during grid fault. |
Key words: wind power LVRT dynamic braking resistance DC Crowbar AC Crowbar reactive power support |