基于线路模型的矿井对地电容在线测量方法的研究

Research on the Method of Mine Distribution Capacitance Online Measured Based on Line Model

随着煤矿供电网络的增大,单相接地电容电流随之增大。电容电流的大小是决定是否要对电网补偿,以及选择补偿设备的重要依据。目前现有的小电流接地系统对地电容的测量方法不适应矿井长期在线测量。因此,本文提出了一种基于线路模型参数识别的矿井对地电容在线测量方法,通过建立每条线路的数学模型,根据接地故障时的零序电压、电流数据,采用最小二乘法求出线路对地电容。经过仿真和实验验证,在绝缘电阻为无穷大的情况下,对地电容识别的误差率小于1%。

With the increase of coal supply network, the single phase to ground capacitance current also increases. The magnitude of capacitance current is the important basis for compensating power network and selecting compensa- tion equipment. The existing method of measuring distribution capacitance with non solid earthed network does not meet the demand of long-term online measurement. Based on the line model parameter identification, an online meas- ure method of distribution capacitance is proposed. The method can be achieved in two steps. Firstly, the mathemati- cal model is built. Secondly, according to zero sequence voltage and current under the condition of earth grounding fault, the distribution capacitance can be achieved based on the least square method. The simulation results show that, if the insult resistance infinite, the error rate of identifying distribution capacitance is lower than 1%.