海上风电机组低电压穿越远端检测

为解决长距离输电海缆对海上风电机组低电压穿越远端检测的影响问题,根据基于风力发电机出口端发展和制定的低电压穿越(LVRT)测试技术和标准,建立了低电压穿越分析模型,提出海上风电机组低电压穿越远端检测方法。按照现有检测方法分析了稳态、暂态情况下远端检测和近端检测的区别,得出远端检测中导致风机切机的外部原因为限流电抗与输电海缆的相互影响使机端电压升高、暂态过程延长、机端电压谐波含量增加。提出利用电力电子开关替代传统检测设备中的断路器,以便能精确控制电抗的动作时间。改进阻抗的动作时序,使短路电抗和限流电抗投入或退出电路的时间间隔最短,以避免限流电抗与输电海缆的相互作用对远端检测的影响。仿真验证了改进检测方法的有效性,为远端检测设备的研制提供了借鉴。

Remote testing on low voltage ride through of offshore wind turbines

In order to cope with the long-distance submarine cable effects on low voltage ride through(LVRT)remote testing for offshore wind turbines(WTs), the LVRT testing model was built and the method for remote testing on LVRT of offshore WTs was proposed according to the existing LVRT testing technique and standards based on the outlet of WTs. The difference between near and remote testing in both steady and transient situations was analyzed according to the existing devices and method, which concluded that the mutual influence of current limiting reactance and cable heightened the voltage of the outlet, prolonged the transient process and increased harmonic component. The circuit breaker of original device was replaced with electronic switches in order to control the operation of reactance accurately. The operation sequence of the reactance was improved to make the action intervals of time between the current-limiting reactance and short-circuit reactance trended to 0. By doing this, the mutual influence of current-limiting reactance and cable could be avoided. A simulation was put forth to verify the effectiveness of the improved process and to provide supports for development of remote LVRT testing equipment at the same time.