Position Sensor Fault Detection of IPMSM Using Single DC-Bus Current Sensor with Accuracy Uncertainty

This paper proposes a position sensor fault detection scheme using single dc-bus current sensor for interior permanent magnet synchronous motor (IPMSM) drives. The three-phase currents are derived from the single current sensor, and the accuracy uncertainty of the sensor is also considered. The six active vectors are divided into three groups for sensor calibration. Then, the proposed dc-bus current sensor offset error calibration method is implemented by setting two opposite basic vectors together and measuring the current values on both sides of the junction point in a same time interval. If the sum of the two sampled currents is not zero, it indicates that the offset error of the dc-bus current sensor exists. Therefore, a corresponding compensation method is proposed. Meanwhile, the dc-bus current slopes under different switching states are closely related to the rotor position, which are utilized for position sensor error detection. Finally, the effectiveness of the proposed scheme is verified by experimental results on a 5-kW IPMSM motor prototype.