确定测量三芯电力电缆芯线电流用磁传感器安装偏角的方法

为解决用磁传感器测量三芯电力电缆各芯线电流过程中磁传感器难以准直的问题,文中提出了一种确定磁传感器安装偏角的方法。采用4个磁传感器,在三芯电力电缆表面4个不同位置测量磁感应强度的切向分量;采用"扫描"算法,消除磁传感器安装偏角在计算过程中带来的非线性影响,将非线性方程组转化为线性方程组进行求解;根据磁传感器的测得值和三芯电力电缆的设计参数,得到各磁传感器的安装位置与电缆内相应芯线的偏角,并可进一步求解出三芯电力电缆各芯线电流的实际大小。电磁场有限元仿真试验和解析模型计算的结果表明,此方法具有较好的准确性,对三芯电力电缆运行状态的有效、准确监测具有指导价值。

Method for determining the declination angle of magnetic sensors for measuring core current of a three-core power cable

In order to solve the problem that magnetic sensors are difficult to collimate when measuring the core current of the three-core power cable, a method for determining the declination angle of magnetic sensors is proposed. Four magnetic sensors are used to measure the tangential components of magnetic flux density at four different locations on the surface of a three-core power cable. The "scanning" algorithm is adopted to eliminate the nonlinear influence of the declination angle of magnetic sensors in calculation process, and the nonlinear equations are converted into linear equations for solving. Based on the measured value of magnetic sensors and the design parameters of the three-core power cable, the declination angle of each magnetic sensor installation position and the corresponding core in the cable are obtained, and the current of each core of the three-core power cable can be solved. The test results of electromagnetic field finite element simulation and analytical model calculation show that this method has good accuracy, and it has guiding value for the effective and accurate monitoring of the operation state of the three-core power cable.