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Author Thunes, J. ♦ Kerkman, R. ♦ Schlegel, D. ♦ Rowan, T.
Sponsorship IEEE Industry Applications Society
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©1972
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics ♦ Electricity & electronics
Subject Keyword Regulators ♦ Voltage ♦ Pulse width modulation ♦ Pulse width modulation inverters ♦ Current control ♦ Space vector pulse width modulation ♦ Frequency modulation ♦ Switching frequency ♦ Inductors ♦ Analytical models
Abstract Parallel inverters are often used to meet system power requirements beyond the capacity of the largest single structure. They have also been used to reduce harmonics, reduce pulsewidth modulation (PWM) switching frequency and increase available output voltage or frequency. The type of parallel structure depends on the construction of the load motor; the most prevalent are dual three-phase machines, split-phase machines, six-phase machines, and a standard three-phase machine with interphase reactors. Operation of parallel structures presents areas for investigation encompassing analysis, simulation, control, and design. This paper reports on the commissioning of a 775 HP dual-winding three-phase motor with parallel inverters. A simple method of paralleling structures with carrier-based PWM current regulators to independently regulate each inverter's current is employed. Experimental results show a loss of current control that is similar to a random event. The instability between the parallel inverters and the common motor can result in large uncontrolled currents. Simulations established that the reduction in controller gain, as the regulator enters the PWM pulse-dropping or overmodulation region, results in a loss of current control. Experimental results show the loss of current control is the result of an interaction between the parallel inverters through the dual-wound three-phase motor. Modifications were made to the modulator and a two-phase discontinuous controller was employed; the gain characteristic of the two-phase modulator in the overmodulation region extends the dynamic range of the motor drive.
Description Author affiliation :: Rockwell Autom.-Allen-Bradley Co., Mequon, WI, USA
ISSN 00939994
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1999-01-01
Publisher Place U.S.A.
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Volume Number 35
Issue Number 1
Size (in Bytes) 244.86 kB
Page Count 8
Starting Page 70
Ending Page 77


Source: IEEE Xplore Digital Library