Document Type
Thesis
Date of Award
12-31-1988
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical Engineering
First Advisor
Walid Hubbi
Second Advisor
Kenneth Sohn
Third Advisor
Anthony D. Robbi
Abstract
A three-phase microcomputer based AC Inverter has been developed using a computational intensive PWM algorithm that generates the output bridge switching patterns in real time. This approach utilizes the on-board capabilities of an advanced microcontroller, (a 16-bit 8097 from Intel), to eliminate most of the external hardware, and demands on memory size, required in other designs. This algorithm implements in software the Triangular Modulation Method of PWM generation, and utilizes a trapezoidal approximation to the sinusoidal reference waveform. Brassboard tests have shown that this approximation produces 5th and 7th harmonics that degraded performance, at low speeds. An enhanced algorithm, utilizing a higher resolution, piecewise linear approximation to a sinusoidal reference has been developed and analyzed, and eliminates all harmonics below the 11th, generating a much improved sinusoidal output to the AC motor at low speeds. This improved design requires some additional software, but does not add any hardware to the basic design, nor does it tax the throughput capability of the microcontroller.
Recommended Citation
Schnug, Luther William, "Microcomputer control of an AC induction motor using a PWM computational intensive method" (1988). Theses. 3205.
https://digitalcommons.njit.edu/theses/3205
