Multi-phase Space Vector Pulse Width Research Articles

Sensorless Speed Control of Five-Phase PMSM Drives in Case of a Single-Phase Open-Circuit Fault

This paper introduces a new method to track saliency in a five-phase permanent magnet synchronous motor in case of a single-phase open-circuit fault. The proposed method depends on measuring the dynamic current response of the motor line currents due to the insulated-gate bipolar transistor switching actions. In case of a single-phase open-circuit fault, a fault-tolerant control strategy to control the remaining healthy currents results in minor system performance degradation. The new strategy that is proposed in this paper to track the saliency includes software modifications only to the saliency tracking algorithm used in healthy mode in order to make it applicable in the cases of a single-phase open-circuit fault. It uses the fundamental pulse width modulation waveform obtained using a symmetric multi-phase space vector pulse width modulation only. Simulation results are provided to verify the effectiveness of the proposed design over a wide speed range under different load conditions.

Sensorless speed control of five-phase PMSM drives with low current distortion

This paper introduces a design for a sensorless control of a five-phase PMSM drive working at low and zero speeds with low current distortion. The rotor position is obtained through tracking the saturation saliency by measuring the dynamic currents responses of the motor due to the IGBTs switching actions. It uses the fundamental PWM waveform obtained using the multi-phase space vector pulse width modulation only. The saliency tracking algorithm used in this paper doesn’t only improve the quality of the estimated position signals but also guarantees a minimum current distortion through reducing the modifications introduced on the PWM waveform. Simulation results are provided to verify the effectiveness of the proposed strategy for saliency tracking and current distortion minimizing of a five-phase PMSM motor drive over a wide speed ranges under different load conditions.

A Modelling and Simulation of a Sensorless Control of Five-phase PMSM Drives using Multi-dimension Space Vector Modulation

This paper introduces a new method to track the saturation saliency for position measurement of a five-phase PMSM motor fed by a five-phase inverter through measuring the dynamic current response of the motor line currents due to the IGBT switching actions. The new method uses only the fundamental PWM waveform obtained using the multi-phase space vector pulse width modulation (i.e there is no modification to the operation of the five-phase inverter) similar to the fundamental PWM method proposed for a three-leg inverter. Simulation results are provided to verify the effectiveness of the proposed strategy for saliency tracking of a five-phase PMSM motor driven by five-phase inverter over a wide speed ranges under different load conditions.

Dual-Inverter-Fed Pole-Phase Modulated Nine-Phase Induction Motor Drive With Improved Performance

Typical value of rated phase voltage of pole phase modulated multiphase induction motor (PPMMIM) drives with wider speed range is in the order of few hundreds of kilovolts. This high value of phase voltage for high power density applications results in higher dc-link voltage requirement and switch voltage rating of two-level multiphase inverter. Further, using multiphase space vector pulse width modulation (SVPWM) yields less dc-link utilization. Methods to increase dc-link utilization using SVPWM with offset value of third harmonic order introduces dominant lower order harmonic currents into phase windings. One more major problem in high pole mode of PPMMIMs is higher torque pulsation due to decrease in phase number. To address these problems this paper proposes a dual-inverter-based multilevel voltage excitation scheme for nine-phase PPMMIM with 1:3 speed ratio. In four-pole mode a simple phase grouping technique to eliminate lower order harmonic currents in the phase windings is proposed. In addition each inverter feeding these phase groups is modulated using carrier-based three-phase SVPWM to achieve higher dc-link utilization. This paper also proposes a multilevel voltage generation scheme for 12-pole mode of operation using carrier phase shifted pulse width modulation (PWM) for inherently available equal voltage profile coils with the same dual inverter structure. The torque ripple using phase shifted carriers PWM and single carrier PWM are compared. Finite element method model of nine-phase PPMMIM is developed in Ansys Maxwell two-dimension and is cosimulated with three three-phase dual inverters in Simplorer environment. Experimental validation is done for linear and over modulation case on 9ФIM fed from three three-phase dual inverters controlled using Spartan six field programmable gate array board programmed in VHDL.

Harmonic Analysis of Multilevel Multiphase Space Vector Pulse Width Modulator for Over Modulation Region

In the recent years, the multi-level converter technology has increased due to the achievement of high power ratings. Also multi-phase converter technology permits more than three phases in drive applications. Multi-level multi-phase combined technology gives the benefits of both technologies. In this paper, analyses the multi-level multi-phase Space Vector Pulse Width Modulator (SVPWM) modulator for over modulation region of operation. The space vector pulse width modulation technique assures linearity till an output of 90.7% of the installed inverter capacity. Over modulation is a non-linear process and it necessitates two modes of operation depending on modulation index (MI). Mode-I for compensating the voltage vector to be applied while mode-II uses the concept of continuous application of a specific voltage vector in order to achieve the desired average voltage vector and hence angular velocity. In this paper, mode-I operation of over modulation is extended beyond usual modulation index thus far reported 0.9535 in the literature survey, thus stretching the arrival of Mode-II further towards six steps. This delay in the arrival of over modulation Mode-II decreases the non linearity effect as the lower order harmonics are reduced, thereby improving the controllability of the angular velocity. This helps in compensating the current and torque ripples in the motor. The acceptable operation of the extensive range of mode-I and the smooth transition into mode-II and six steps is verified using simulation results. The simulation results discussed about the odd harmonics with and without over modulation region.

Multi-phase space vector pulse width modulation: Applications and strategies

Multi-phase machines and drives is a topic of growing relevance in recent years, and it presents many challenging issues that still need further research. This is the case of multi-phase space vector pulse width modulation (SVPWM), which shows not only more space vectors than the standard three-phase case, but also new subspaces where the space vectors are mapped. Different approaches have been recently followed, and the aim of this paper is to review and classify these methods. Comparative results are included to highlight the weak and strong points of the different methods. Finally some conclusions are extracted pointing out the problems that still need to be solved.