Vector Control of Asymmetric Dual Three-Phase PMSM in Full Modulation Range

Abstract

The total control range of asymmetric dual three-phase permanent magnet synchronous motor (ADT_PMSM) is divided into three different segments by voltage modulation range and current control dimensions and respective control strategies to get the injected voltages in harmonic subspace for three segments are presented in this paper. The three segments are sinusoidal current modulation region, sinusoidal voltage modulation region and overmodulation region. In sinusoidal current modulation region, resonant controller is adopted in the harmonic subspace to calculate the injected voltages, which can compensate the effect of six-phase voltage source inverter (VSI) dead time for two sets of three-phase windings and takes the pole correction into consideration. In sinusoidal voltage modulation region, open loop control strategy in harmonic subspace is adopted. Overmodulation region 1 and 2 are defined in overmodulation region, and the harmonic voltages which are injected into harmonic subspace to extend the modulation index are calculated based on superposition principle and VSD theory. In order to achieve smooth transition from different regions, a novel space vector pulse width modulation (SVPWM) technique for ADT_PMSM is proposed. The experimental results demonstrate the validity and feasibility of the suggested control approach.

A Comprehensive Survey on Fault Tolerance in Multiphase AC Drives, Part 1: General Overview Considering Multiple Fault Types

“…Although in presence of space harmonics in the secondary subspaces there is certain coupling with the rotor and hence higher impedance, it is still considerably lower than in the plane of the fundamental component. Hence, even small voltage components can produce undesired large currents that need to be taken into account and/or compensated [139,143,202,487,488,493,494].…”

“…[154,157,158]. In [139], another overmodulation SV PWM technique considering the two winding sets separately is presented. For m between 1.155 p.u.…”

“…Since the machine back-EMF tends to increase with speed, if v dc decreases then the maximum speed and power are reduced as well [141,171]; • If the modulation index increases beyond the linear modulation range, overmodulation occurs. This means that low-order voltage harmonics are introduced, the VSD subspaces become coupled in terms of voltage, and the conventional PWM and control methods are no longer able to work properly [8,9,134,135,[137][138][139]142,143,145,[147][148][149][150][151][152][154][155][156]158,159,167]; • If the VSC ac voltage is reduced, the difference between its magnitude and that of the machine back-EMF may become substantially greater. As a consequence, overcurrent may occur [129,545].…”

Multiphase Traction Inverters: State-of-the-Art Review and Future Trends

“…In general, for any n odd number of phases, voltage and current vectors are mapped into (n − 1)/2 orthogonal subspaces. VSD-based SVPWM for n = 6 can be classified as 12sector based [24], [58], [65], [66] and 24-sector based techniques [67]- [69]. The latter is digitally easier to implement and yields reduced current harmonic distortion.…”

Advances in Dual-Three-Phase Permanent Magnet Synchronous Machines and Control Techniques

“…In [137,138], an overmodulation (OVM) strategy is proposed on the basis of SVPWM in [62], where the desired voltage vector in the αβ subspace was synthesized using two adjacent active vectors. This resulted in large current harmonics in the z 1 -z 2 subspace.…”