Operation of single-phase induction motor as two-phase motor

Abstract

In this paper, it is proposed to drive a single-phase induction motor with a two-phase supply. The two-phase supply is obtained from the conventional single-phase utility supply by using a two-phase inverter. The adverse effects of most of the harmonics associated with the use of the two-phase inverter are alleviated by cancelinglattenuating the dominant harmonics in the motor terminal voltages using the selective harmonic elimination (SHE) pulse width modulation (PWM) technique.. The performance of the motor is analyzed using computer simulation and is then compared with that of a conventional single-phase capacitor start induction motor. For a comprehensive comparison, the analysis is performed at both the transient and steadystate cases. Furthermore, frequency analysis is conducted with a view to provide more insight into the operation of the proposed scheme. The proposed mode of operation allows the single-phase induction motor to gain the advantages of the poly-phase motor such as starting torque, less torque harmonics and higher rated power. 1. r,=2.0I R, Pc,,e=17s w, X,,,=2.01 Q, r,=1.3 R, &r=&d, p(r,,.,,."+w,"d.p.)=75 w. Where, xmd, X,, are the direct and the quadrature The subscript "6' denotes d-axis quantities,The subscript "q" denotes q-axis quantities, The subscript '3" denotes stator, The subscript "r" denotes rotor,The subscript "P' denotes leakage. mutual reactance, respectively.

Adjustable-speed Unsymmetrical Two-phase Induction Motor Drive for Photovoltaic Powered Air Conditioners

“…For the one-phase motor parameters given in Appendix A, it was shown that, at the same value of steady-state slip, the motor produces 23.4% more power when operated in Downloaded by [University of Nebraska, Lincoln] at 09:46 03 January 2015 the two-phase mode of operation [1]. In other words, for a 1.5-hp one-phase IM operated in the two-phase mode, the new motor output power becomes P out D 1:234 1:5 D 1:851 hp D 1:3801 kW: (8) Referring to Figure 1, the motor output power can be written as…”

“…With the motor reactive power provided by the inverter, the PV array has to supply only the active power required by the motor [16]. Thus, for a motor output of 1380.9 W, and an overall motor efficiency of 84% [1], the motor input active power is given by P ac D 1380:9 0:84 D 1643:9 W:…”

“…First, it rids the motor of the backward component of the air gap flux, hence decreasing the motor iron losses, leading to higher motor efficiency. Second, it endows the "one-phase" IM with the merits of poly-phase motors such as non-zero starting torque, low torque pulsations, and higher output power for the same motor frame size [1]. Third, it departs from conventional energy sources that have become less favorable with the ongoing increase in fuel prices as well as the growing awareness of the environmental impact of fossil fuel consumption.…”

An Unsymmetrical Two-Phase Induction Motor Drive With Slip-Frequency Control

“…1), thus allowing the use of a lower frame size to drive the same load. Running costs have been reduced by reducing the motor losses and improving its power factor, thus enhancing the motor efficiency [8].…”

“…This resulted in increased torque harmonics as well as reduced motor overall efficiency. To alleviate such problem, a phase difference angle (PDA) control employing the pulsewidth modulation (PWM) selective harmonic elimination technique has been reported in [3] Manuscript received September 6, 2006 Torque-speed characteristics are improved when the single-phase IM is operated as an unsymmetrical two-phase motor [8].…”