基于频率自适应 PLL 的传动系统牵引电机转速实时估计

为满足传动系统在牵引电机无速度传感器控制、速度传感器异常诊断与预测等领域对牵引电机转速精确估计的要求,提出了一种基于频率自适应锁相环的转速实时估计方法。首先针对传统锁相环(PLL)算法无法实现频率大范围跟踪问题,提出了一种前馈参考频率自适应调节的二阶广义积分锁相环(RFSOGI-PLL)算法,实现定子电流基波频率的大范围实时跟踪;再利用牵引电机转速与定子电流基波频率以及齿槽谐波关系模型,结合电机结构参数,实现了传动系统牵引电机转速大范围实时估计;最后在某型大功率交流传动系统上对所提算法的有效性进行了验证。仿真与试验结果表明,与传统PLL算法相比,所提的RFSOGI-PLL算法可有效提升算法对跟踪频率变化的适应性,满足牵引电机转速估计在快速性和估计误差等指标方面的要求。

Real-time estimation for traction motor speed of drive system based on PLL with adaptive frequency

In order to meet the requirements of the drive system for the accurate estimation of the speed of traction motor in the fields of speed sensorless control, abnormal diagnosis and prediction of speed sensor, etc. , a real-time speed estimation method based on frequency adaptive phase-locked loop is proposed. Firstly, to solve the problem that traditional phase-locked loop ( PLL) algorithm cannot track the frequency in a large range, a second-order generalized integral phase-locked loop algorithm with feed-forward reference frequency self-adaptive adjustment (RFSOGI-PLL) is proposed to track the fundamental frequency of stator current in a large range in real time. Then, using the relation model of speed of traction motor, fundamental frequency of stator current and cogging harmonic, together with the structural parameters of traction motor, the traction motor speed of the drive system can be estimated in a large range in real time. Finally, the effectiveness of proposed algorithm is verified on a high-power AC drive system. The simulation and field test results show that, compared with the traditional PLL algorithm, the RFSOGI-PLL algorithm proposed in this paper can effectively improve the adaptability of the algorithm to track frequency change, and meet the requirements of traction motor speed estimation in celerity and estimation error.