Comparative analysis of different FOPI approximations and number of terms used on simulations of a battery-powered, field-oriented induction motor based electric vehicle traction system

Mazen Elsaadany, Muhammad Qasim Elahi, Faris Nihad AtaAllah, Habibur Rehman, Shayok Mukhopadhyay

Abstract:

Because of their enhanced performance, the fractional order proportionalintegral (FOPI) controllers are becoming an appealing choice for controlling
induction motor speed. To implement FOPI controllers, several fractional order
integral approximations are available in the literature. The approximation used,
and the order of approximation affects the speed tracking, transient response,
and induction motor power consumption. This further affects the energy
consumption analysis if simulations are conducted based on such
approximations. In this paper an electric vehicle (EV) traction system is
simulated to investigate the effect of such approximations on the
simulations of a battery powered, induction motor driven EV system. The
system consists of an indirect field-oriented induction motor, a lithium-ion
battery bank, and a three-phase inverter. This work presents a quantitative
analysis of the performance of FOPI controllers using different approximations,
and order of approximations is presented. The controllers are evaluated based
on speed tracking, transient response, computational time, and power
consumption. Both step functions and standard drive cycles are used as the
speed reference signal to evaluate the effects of using different approximations
and different orders of approximation, when different references are used. This
work establishes a reference set of simulations that can be used to infer the
amount of error in battery state of charge, and state of health analysis
conducted on such an EV system, when dealing with FOPI controllers under
different approximations and related settings.