Raul Rabinovici

New procedures for minimizing the torque ripple in switched reluctance motors by optimizing the phase-current profile

This paper introduces five new optimization procedures for the minimization of the torque ripple in the switched reluctance motor (SRM). These new procedures are based on the optimization of the phase-current profile. Two optimization techniques, the simplex method and the genetic algorithm, are adapted to these optimization procedures. The paper compares an older optimization procedure, the optimum harmonic current injection procedure, and the new optimization procedure, and presents conclusions.

Envelope simulation by SPICE-compatible models of electric circuits driven by modulated signals

SPICE-compatible equivalent circuits were developed to facilitate the analysis and envelope simulation of electric circuits driven by modulated signals. The circuits are based on a novel complex phasor domain transformation. The proposed method facilitates fast simulation of any general linear circuit driven by a modulated signal, such as amplitude, frequency, or phase modulation.

Switched Reluctance Machines as Three-Phase AC Autonomous Generator

The operation of the switched reluctance machine as an autonomous three-phase ac generator is considered. Two circuits are proposed. The generator circuit consists of only capacitors and load supplementary to the generator, but does not contain any power supply. Theoretical approaches for simulation of the three-phase autonomous switched reluctance generator are presented. The influence of the high harmonics in the phase current on the power output is discussed. Experimental and simulation results are presented

Mobile robot characterized by dynamic and kinematic equations and actuator dynamics: Trajectory tracking and related application

This paper establishes control strategies for wheeled mobile robots which are subjected to nonholonomic constraints. The mobile robot model includes the kinematic and dynamic equations of motion and the actuator dynamics. Using the notion of virtual vehicle and the concept of flatness, and applying the backstepping methodology the paper proposes control schemes for trajectory tracking for the considered augmented model of the mobile robot. The resulting controller ensures exponential convergence to a desired trajectory. Applications of the tracking controller for convoy-like vehicles governed by the augmented models are considered as well. Simulation results and lab experiments are demonstrated.

Virtual torque and inertia loading of controlled electric drive

This work presents a simple method to obtain effects similar to those obtained by real mechanical loading and real inertia variation but without any mechanical parts supplementary to the electric motor of the studied electric drive. The electric motor itself produces the load torque and the inertia variation using digital signal processing software. Therefore, the electric drive is virtually torque and inertia loaded, while its behavior is similar to that of the actual loaded drive. The present method could be used to test the implementation of control algorithms or for didactic purposes using motion control kits found on the market. The present method is used with laboratory works of the DSP Fundamentals in power electronics course at the Department of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel.

Inductance measurements in switched reluctance machines

We propose a simple method for measuring the parameters of switched reluctance machines. We compare our method with two other methods for evaluating inductance under conditions of strong magnetic saturation. We present the results of our measurements and those of finite-element simulations.

Envelope simulation by SPICE compatible models of electric circuits driven by modulated signals

SPICE compatible equivalent circuits were developed to facilitate the analysis and envelope simulation of electric circuits driven by modulated signals. The circuits are based on a novel complex phasor domain transformation. The proposed method facilitates simulation of any general linear circuit driven by a modulated signal such as AM, FM or PM. Simulation time by the proposed envelope simulation is much faster than the full cycle-by-cycle simulation of the original circuit and excitation.

Speed and position estimation of brushless DC motor in very low speeds

The paper proposes a method to detect and control the speed and the position of a BLDC motor with a low resolution position encoder in very low speeds of several rad/sec. The low resolution encoder could be the Hall effect sensor that has a resolution of 60 electrical degrees maximum, according to the pole number of the motor. The proposed algorithm used a Kalman filter (KF). The position and the current are sampled. The algorithm was simulated on MATLAB/spl copy/, and the simulation results were valuable.

Switched reluctance machines as three-phase AC autonomous generator

The operation of the switched reluctance machines as an autonomous three-phase AC generator is considered. Two schemes are proposed. The generator circuit consists of only capacitors and load supplementary to the SRM, but does not contain any power supply. New theoretical approaches for simulation of the three-phase autonomous switched reluctance generator are presented. The influence of the high-harmonics in the phase current on the power output is discussed. Experimental and simulation results are presented.

Simple model of switched-reluctance Machine based only on aligned and unaligned position data

We propose a simple equivalent circuit and mathematical model for the magnetic system of switched-reluctance machines (SRMs). The saturation effect in the stator yokes is taken into account, and phase inductance is represented as a function of phase current and reluctance in the air gap. We also propose a simple method for measurement and evaluation of the parameters of SRMs based on the model and present results of numerical simulations and real experiments on an SRM as an autonomous single-phase generator.