一种感应电机无速度传感器系统的电流传感器容错控制策略

A Current Sensor Fault-tolerant Control Strategy for Speed-sensorless Induction Motor System

在无速度传感器感应电机驱动系统中,需要利用电流传感器提供电流信号以实现速度估计。然而,电流传感器作为驱动系统的脆弱部件,易发生故障。当电流传感器出现故障时,系统控制性能显著恶化。为进一步提高感应电机驱动系统的可靠性,该文研究一种适用于感应电机无速度传感器系统的电流传感器容错控制策略。该方案通过坐标变换实现电流传感器的故障诊断,并利用二阶广义积分器–锁频环重构故障电流信息,并将其反馈到基于滑模观测器的速度估计方案中,实现感应电机无速度传感器控制系统的电流传感器容错控制。此外,在所提出的控制策略中进一步采用改进型二阶广义积分器–锁频环,以克服直流偏置带来的不利影响。最后,利用实验测试验证所研究方法的可行性。

In the speed-sensorless control of induction motor drives system, current sensors are used to provide current signals to achieve speed estimation. However, as one of most fragile components in traction drive system, current sensors are prone to failure. When current sensor faults occur,the control performance of traction drive system may be degraded. To further improve system reliability of induction motor drives, a fault-tolerant control strategy of current sensor for speed-sensorless-controlled induction motor drives was proposed in this paper. This scheme achieved fault diagnosis of the current sensor through coordinate transformation, and then a second-order generalized integrator-frequency-locked loop(SOGI-FLL) was used to reconstruct the faulted current information. Accordingly, the reconstructed current was fed back to the sliding mode observer(SMO)-based speed estimation scheme. With this, the fault-tolerant control of current sensor for speed-sensorless-controlled induction motor drives was realized. Moreover, an improved SOGI-FLL was further used in the proposed control strategy to eliminate the adverse effects of DC offsets. Finally, extensive experimental tests are performed to verify the effectiveness of the proposed control strategy.