Open-Circuit Fault-Tolerant Control of a Six-Phase Asymmetric Permanent Magnet Synchronous Motor Drive System

Abstract

One innovative composite fault-tolerant control tactic is presented for the reliable operation of a power transmission system, which consists of both an asymmetric six-phase permanent magnet synchronous motor (PMSM) and a T-type mid-point clamp type (T-NPC) three-level inverter. First, in order to inherit the better harmonic property of simplified space vector modulation (SVM) and the rapid dynamic capability of direct torque control (DTC), the SVM-DTC control scheme was determined, and the harmonic electric current suppression unit was added to the basic control scheme to obtain good harmonic electric current suppression. In addition, a strategy for open-circuit fault-tolerant control under the SVM-DTC scheme was designed by analyzing the mutual influence between the stator flux linkage and the stator voltage of each phase under an open-circuit fault. Finally, the PMSM drive system principle prototype was tested. By comparing the waveforms of output torque and current of each phase before and after fault tolerance, it shows that the large torque fluctuation (±5%) before fault tolerance was suppressed to ±2% and smoothed out, verifying the effectiveness of fault tolerance control.

PMSM Field-Oriented Control with Independent Speed and Flux Controllers for Continuous Operation under Open-Circuit Fault at Light Load Conditions

“…Using MPTC-SVM provides a good transient response, improves the overall performance, and reduces the harmonics. Proposed in [20] is a fault tolerance control of a six-phase asymmetric PMSM under OCF operation. Space-vector modulation using direct-torque control (SVM-DTC) was used.…”

Research on Two Improved High–Voltage–Transfer–Ratio Space–Vector Pulse–Width–Modulation Strategies Applied to Five–Phase Inverter

“…The multiphase motor drive system has a lower torque ripple and fault tolerance performance, which is more suitable for occasions with high accuracy and reliability [1][2][3][4][5]. And its low-voltage and high-power characteristics can avoid voltage and current sharing problems caused by series and parallel power devices in three-phase power circuits [6,7].…”

A Method Based on Phase-shifting Carrier for Reducing DC-link Current Harmonics in Dual Three-phase PMSM Drive under Open-phase Conditions

“…For the multi-phase motor model, the advantages of the multi-degree of freedom can be fully utilized by establishing a generalized zeroorder subspace and decoupling the six-phase current vector. Reference [3] established a mathematical model of two open-phase faults with arbitrary position relation but did not consider stator leakage inductance. Reference [4] has conducted a detailed analysis of how to use the residual phases of a multiphase motor in the fault condition to balance the current and generate the balanced torque.…”