An efficient PWM technique for split phase induction motor operation using dual voltage source inverters

Abstract

Split phase induction motor operation from dual PWM voltage source inverters offers the advantage of reduced voltage rating for the inverter devices. In addition, a total of 4 9 different locations are possible for the resultant stator voltage space phasor. The outermost locations form a twelve sided polygon. By space phasor PWM generation based on the vertices of the twelve sided polygon, a higher range of fundamental motor voltage is possible in the modulation range, up to 0.643 VD , where VEC is the DC link voltage for an equivalen$ 3 phase inverter, as compared to 0.577 VDc for the three phase motor. This is brought about by the presence of 5th and 7th harmonics in the average poler voltage waveform.

A Two-Frequency Quasi Six-Phase Voltage Source Inverter Based on Space Vector PWM

“…At the higher end of the speed range a voltage space vector modulation based on the 12 sided polygonal vertices is used, so that the benefit of a higher voltage is retained. Although no low-order harmonic currents are observed in a traditional hexagon-based SVM, in a 12-sided polygon-based SVM presented in [9], low-order harmonics are generated in the drive system due to the elimination of some switching state vectors that appreciably contribute to harmonic elimination.…”

“…In [10] using the technique of [9] and classification algorithm an optimized over-modulation strategy is proposed to improve the harmonic contents, better utilize the inverter, and simplify the control.…”

“…The SVM schemes of [9] and [10] are based on two separate three-phase VSIs; therefore the six-phase inverter achieved can generate only one fundamental output frequency.…”

“…In [9] a SVM strategy is proposed for a QS induction motor (IM) drive, wherein at low speeds two three-phase inverters is operated with conventional three-phase space vector modulation, thereby…”

Vector control of dual-three phase induction motor drives using two current sensors

“…The best solution to minimize the excitation of the (µ 1 ,µ 2 ) subspace is to use dedicated Space Vector Modulation (SVM) techniques [7,11]. However, if the machine uses full-pitch stator windings, satisfactory results can still be obtained using simple modulation techniques, such as the double SVM [12] or the double zero-sequence injection [13] techniques. These solutions yield quasi-sinusoidal machine phase currents employing conventional three-phase PWM modulators [12,13].…”