Jan Deskur, Tomasz Pajchrowski and Krzysztof Zawirski
The purpose of this paper is to propose a method of optimal control of current commutation of switched reluctance motor drive.
Abstract
Purpose
The purpose of this paper is to propose a method of optimal control of current commutation of switched reluctance motor drive.
Design/methodology/approach
The problem of optimal current commutation control is solved by off‐line selection of switching‐on and switching‐off angles. Selection of optimal values of angles is provided on computer model of the drive with help of particle swarm optimisation method. The optimal angle values are detected as functions of phase current and rotor speed. These calculated optimal values are stored in microcomputer control system memory in form of two‐input look‐up tables. The results are validated on laboratory set up.
Findings
Three different criteria of optimal control, which are taken into account: the maximum electromagnetic torque for given reference current, the maximum ratio of electromagnetic torque to root mean square value of phase current and the minimum electromagnetic torque ripples, gave a good results validated by simulation and experimental investigations.
Practical implications
A simple control method is proposed to optimise switched reluctance motors drive behaviour. Such an approach can be recommended for practical implementations.
Originality/value
The off‐line optimisation of switching angles, which is realised on computer model, is sufficient to obtain a good control effect.
Details
Keywords
The paper presents a method of creating electrical equivalent diagrams of magnetic circuits. The method is based on bond‐graph techniques, using flux derivative as flow variable…
Abstract
The paper presents a method of creating electrical equivalent diagrams of magnetic circuits. The method is based on bond‐graph techniques, using flux derivative as flow variable. Couplings between magnetic and electric part of the system are represented by gyrators. Simple models of magnetic branches, including non‐linear effects due to saturation, hysteresis and eddy currents, are presented. These models can be easily combined into magnetic circuit models, which can be transformed into dual electric equivalent circuit. Various equivalent circuits of transformers are discussed. The proposed models are simple and particularly useful for system‐level simulation of power electronic and motion control systems with magnetic elements. These models can be easily developed if needed. Theoretical considerations are illustrated by examples of digital simulation and experimental results.
Details
Keywords
Jan Deskur, Tadeusz Kaczmarek and Krzysztof Zawirski
Improvement of the dynamic properties of DC drive in the field weakening range was the aim of investigation. The non‐linear model of the drive system was applied. In the paper…
Abstract
Improvement of the dynamic properties of DC drive in the field weakening range was the aim of investigation. The non‐linear model of the drive system was applied. In the paper results of the comparative analysis of two emf control structures are presented. The classic emf control structure with subordinated excitation current control loop was compared with this one consisting of a non‐linear compensation block. For both control structures different kinds of the parameter designing for the emf and excitation controllers are considered. Verification of the theoretical assumptions and synthesis methods of the investigated control structures are made by simulation tests using the PSpice language.
Details
Keywords
Ján Vittek, Peter Briš, Pavol Makyš and Marek Štulrajter
The purpose of this paper is to discuss the design and verification of a new control algorithm for the drive with permanent magnet synchronous motor (PMSM) and flexible coupling…
Abstract
Purpose
The purpose of this paper is to discuss the design and verification of a new control algorithm for the drive with permanent magnet synchronous motor (PMSM) and flexible coupling based on “Forced dynamics control”. Control laws are derived and tested for the rotor and load angle control and achieve non‐oscillatory position step response with a specified settling time.
Design/methodology/approach
“Forced dynamics control” is a new control technique based on feedback linearization which forces rotor or load position to follow demanded position with prescribed closed‐loop dynamics. The proposed control structure is developed in two steps: first, the feedback linearisation is applied to the rotor speed and then similar technique is used for position control loop.
Findings
The proposed controller is of the cascade structure, comprising an inner speed control loop, respecting vector control principles and outer position control loop designed to control the rotor or load angle, respectively. Estimates of load torques acting on the motor and load side as inputs of control algorithms are produced in observers and used to compensate disturbances offering a certain degree of robustness. Preliminary experiments confirm that proposed system follows the ideal closed‐loop dynamics with moderate accuracy.
Research limitations/implications
The focus is on experimental verification of the position control of flexible PMSM drive with two position sensors and moderate precision, where the oscillations due to hardware setup, achieved sampling frequency and corresponding observers adjustment are limited up to 50 rad s−1.
Practical implications
The designed control structure can substantially improve control performance of industrial plants subjects to torsion oscillations.
Originality/value
Experimental results of a novel control structure for the PMSM drives with torsion oscillations are sufficiently promising and confirmed that the rotor and load angle responses follow the prescribed ones fairly closely.