LVRT requirements低电压穿越要求
Three-phase faults in the sub-transmission system 110 kV110kV次输电系统发生三相故障
Transformerstation变电站Meshed sub-transmissionsystem, e.g. 110 kV网状次输电系统，比如110 kVTransformerstation变电站Three-phase fault三相故障Wind farm breakerremains closed风电场断路器保持闭合Wind farm风电场Substation变电站Circuit breaker closed断路器闭合Circuit breaker open断路器断开20
LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
LVRT requirements低电压穿越要求
Three-phase faults in the sub-transmission system 110 kV110kV次输电系统发生三相故障
Operation of high-voltage protection
高压保护动作
Highest operating voltage 最高运行电压Lowest operating voltage最低运行电压Voltage collapse tovery low values, no tripping of wind farm breaker due to missingshort-circuit current 电压跌落至很低，由于没有短路电流以致风电场断路器没有跳开Operation of low-voltage protection低压保护动作Instant of three-phase fault瞬时三相故障
Worldwide first Low-voltage ride through requirement of the TSO E.ON Net in 20032003年输电系统运营商E.ON Net 提出的全世界第一个低电压穿越要求
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
LVRT requirements低电压穿越要求
Three-phase faults in the sub-transmission system 110 kV
??Alternatives for voltage dips 110kV次输电系统发生三相故障
between limits 1 and 2
??在界限1和2之间的电压跌落二中选一
??Selected by TSO由TSO选择??Wind farm circuit breaker operated by opening of line breakers
??通过断开线路断路器操作风电场断路器
àRemote control system necessary, costextensiveà远程控制系统很有必要，成本很大
??Setting of low-voltage
protection to suitable values e.g. to 30% Un, 300 ms
??低压保护设定为适宜值，比如30%Un，300ms
??In certain cases distance protection relay for the wind farm breaker adequate.
??某些情况下，距离保护可满足风电场保护的要求
Voltage limit电压界限1Voltage limit 电压界限2
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
LVRT testingLVRT测试
Principles of wind farm connection to the system风电场接入系统原则
Wind farm system,Medium Voltage , e.g. 20 kV风电场系统，中压，
比如20kv
Transformer Rated powere.g. n times 2 MVA变压器额定容量比如，2 MVA的n倍
Sub-transmissionsystem , e.g. 110 kV
次输电系统，比如110kv
Wind farm connection cable风电场连接电缆
WTWTWTWTWTPCC
Wind turbines风电机组e.g. n units at 2 MVA
比如，n台2 MVA风电机组
Voltage at PCC of the wind farm during fault determined by impedances of the sub-transmission system
故障期间风电场并网点电压由次输电系统的阻抗决定
Impedances of subtransmission small compared to impedances of the wind farm system与风电场系统的阻抗相比，次输电系统的阻抗很小
Wind turbines are connected to the sub-transmission system though transformer and cable impedances which are practically constant during and afterthe fault
风电机组通过变压器和电缆接入次输电系统，但它们的阻抗在故障期间及故障之后保持不变
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LVRT Workshop Beijing 06./07. January 2009Weck: LVRT requirements and testing
LVRT testingLVRT测试
Principles of wind farm connection to the system风电场接入系统原则
WTWTWTWTWTTested WT被测风电机组
??n transformersn台变压器
rated power of each WT
e.g. 2 MVA
每台风电机组额定容量，比如2 MVA??Short-circuit testing in the sub-transmission system not permitted
不允许在次输电系统进行短路测试
Simplifications had to be adopted必须进行简化
1. Neglection of the impedance of the wind farm cable connection忽略风电场连接电缆的阻抗
2. Separation of the wind farm transformer with n times the power of the WT into n parallel transformers with the power of the WT
将容量为n倍风电机组功率的风电场变压器分成n台容量为风电机组功率的并联变压器
3. Simulation of the fault on one WT and at the wind farm voltage level
在一台风电机组和风电场电压等级模拟故障
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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 - 图文
