Load-current-based current sensor fault diagnosis and tolerant control scheme for traction inverters

Based on analysing the load currents, a current sensor fault diagnosis method for three-phase voltage source inverters in high-speed railway electrical traction drive system is presented. Then, a fault-tolerant algorithm is applied to reconstruct the three-phase currents. This fault diagnosis and tolerant control approach is an extension of the normalised average currents method, which requires no additional hardware and permits much more robust diagnostics. Experimental results confirm the effectiveness and accuracy of the proposed algorithm. It is shown that such diagnosis method can locate the faulty sensor, identify the fault modes, and recover the drive system in a fundamental period which is important to avoid catastrophic consequences.