LVRT test equipment today现今LVRT测试设备
Voltage transformers and circuit breakers for WT testing up to 8MW, 30 kV最高达8 MW、30 kV的风电机组测试用变压器和断路器
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
German Grid Codes today现今德国并网导则
TransmissionCode 2007 –Reactive current requirements输电导则2007-无功电流要求
??Generation of reactive current during faults
Additional reactive current
??故障期间发出无功电流额外无功电流Us
ΔIb/Ir
Uwf
I
Voltage change
电压变化ΔU/Un
IXUsUs=Uwt+I?X
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Negative reactive currentincrease voltage at farm.
WFReaction is voltage supporting.
负的无功电流提高风电场电压。Uwf反应是支撑电压。??
Positive reactive current??decrease voltage at farm.
Reaction is voltage degrading.正的无功电流降低风电场电压。反应是降低电压。
??Reactive current at generator side of WT
??风电机组发电机侧无功电流??Current proportional to voltage collapse
??电流与电压跌落成比例
??Minimum value acc. to line with factor k = 2
??依据线路情况最小值系数k=2??E.g. at voltage reduction to 50 % reactive current equal ratedcurrent??比如，当电压减小至50%时，无功电流等于额定电流
Regulation time ≤20 ms调整时间≤20 ms
??Definition needs furtherspecifications
??定义需要进一步规范
LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
German Grid Codes today现今德国并网导则
TransmissionCode 2007 –Reactive current requirements输电导则2007-无功电流要求
Proportionality of reactive current with voltage collapse achieved by modified software control
通过修改过的软件控制无功电流与电压跌落的比例Low-voltage ride through is state of the art低电压穿越是最新技术
Adequate reactive current generation is still in development发出足够大的无功电流仍在发展过程中
Example of successfull reactive current generation成功的发出无功电流示例
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
Protection specifications保护规格
Protection systems for busbar connected plants
??Overvoltage prot.与母线相连电厂的保护系统
??????????
过压保护U> and U>>
Undervoltage prot.低压保护U< and U<<
Overfrequency prot.高频保护f> = 51,5 Hz
Underfrequency prot.低频保护f< = 47,5 Hz
Distance protection距离保护Z<
Reactive power and undervoltage protection无功功率和低压保护Q→&U<
Uc: operating voltage
of the distribution systemUc: 配电系统运行电压
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
Protection specifications保护规格
Protection system settings at busbar母线上保护系统设定值
Uc: operating voltage
of the distribution systemUc: 配电系统运行电压
??Overvoltage protection U>> = 1,15 Uc, retardation 0,1 s过压保护U>> = 1.15 Uc, 延时0.1 s
??For immediate switching-off, when island system with uncontrolled voltage may exist??当孤岛系统电压可能失控时能立即切断
??For retarded switching-off, when voltage tolerance may be exceeded??当可能超出电压容许度范围时能延后切断
??Overvoltage protection U> = 1,08 Uc, retardation 1 min 过压保护U> = 1.08 Uc, 延时1 分钟??Undervoltage protection U< = 0,8 Uc, retardation 2,7 s低压保护U< = 0.8 Uc, 延时2.7 s
??For remaining energized for the full time of LVRT specified in TransmissionCode 2007??在输电导则2007规定的LVRT全时间内能保持通电
??For avoiding current feedback at faults in the high-voltage system??避免高压系统故障时的电流反馈
??Distance protection距离保护
??Reactive power and under voltage Q→&U< = 0,8 Uc, retardation 0,5 s??无功功率和低电压Q→&U< = 0.8 Uc, 延时0.5 s
??For switching-off, when voltage is low and reactive power is still consumed after 0,5 s??当电压很低且0.5s后仍消耗无功功率时切断电路
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
低电压穿越(LVRT)要求及测试
