配电变压器低压侧脉冲注入故障测距方法

Fault Location Method of Pulse Injection in Distribution Transformer’s Low Voltage Side

针对现有主动式行波定位方法对于配电网末端故障难以定位且存在安全隐患等方面的不足,该文提出一种从配电变压器低压侧注入脉冲来实现故障测距的方法。首先,基于实际测量的2种配电变压器模型参数,提出脉冲注入策略。对比测试不同形状、脉宽、注入方式及变压器类型对高压侧所得信号的影响,选用干式变压器单相注入三角脉冲来进行故障测距。然后,对脉冲信号在不同状况下的注入点响应信号进行比较,使用变分模态分解(variationalmode decomposition,VMD)-Teager能量算子(Teager energy operator,TEO)方法分离出突变点时刻,从而计算出故障距离。搭建基于PSCAD的低压侧脉冲注入故障测距模型和长度为935m的脉冲注入测距平台,两者所得测距误差小于50m,表明在一定接地电阻故障下所提方法能实现配电网故障测距,有助于提高主动式行波定位方法的适用性。

To solve the shortcomings of the existing active traveling wave location methods,such as the difficulty in locating the fault at the distribution network’s terminal and the existence of security risks,a method of fault location by injecting pulse from the low voltage side of the distribution transformer was proposed.Firstly,based on the measured parameters of two distribution transformers,a pulse injection strategy was proposed.The effects of different pulse shapes and widths,injection methods and transformer types on the signals obtained from the high-voltage side were compared and tested,and single-phase injection of triangular pulses through dry-type transformers was selected for fault distance measurement.Then the response signals of pulse signals at injection points under different conditions were compared,and the VMD-TEO method was used to extract the mutation points,so the fault distance could be calculated.The low-voltage side pulse injection fault location model based on PSCAD and the pulse injection location platform with a line length of 935m were established,and the errors of fault distance of two experiments were less than 50m,which indicates that the proposed method can find the fault location of distribution network under a certain ground resistance fault,and is helpful to improve the applicability of the active traveling wave location methods.