矿用电动轮自卸车制动时电机过流故障分析

Analysis of overcurrent fault occurred when electric mining haul truck brakes

巨型矿用电动轮自卸车在采矿业、大型工程建设行业发挥重要的作用。实际运行中发现其电力传动系统在自卸车高速运行状态下制动容易发生过流故障,由于系统硬件限制无法使用传统调试方法实时观察程序运行情况。本文提出一种基于逆向技术的过流故障分析方法,即利用逆变器输出实测电压推算得到控制程序中空间电压参考矢量幅值和相位的实时值,以用于故障分析。在本文的分析案例中,采用该方法发现了程序中空间电压参考矢量的瞬时频率突变是导致过流故障的直接原因,进一步分析发现转速采样信号受到了高频干扰致使空间电压参考矢量的瞬时频率突变,文中给出具体措施,有效地解决了过流故障问题。

Huge electric mining haul trucks are widely used in mining industries,which greatly increases the efficiency of ore transportation in mines. Overcurrent faults easily occur in the motor drive system when trucks brake in high speed area. As the limit of hardware of the system,traditional debug method is no longer accessible. In this paper,a new overcurrent fault analysis method based on reverse technology is proposed,which is to get the realtime value of voltage space vector in the control program from the measured real-time inverter output voltage. In the overcurrent fault case in this paper,this method is applied and it proves that the sudden drop of transient frequency of voltage space vector causes overcurrent,which are because of the electromagnetic interference of speed feedback signal after further analysis. Detailed solution is given to solve this problem. Experiment proves the effectiveness of the solution.