Prof. Ján VITTEK & Dr. Juraj ALTUS University of Žilina, SK University of Žilina, SK Department of Electric Traction and Energetics Department of Electric Traction and Energetics Prof. Stephen J. DODDS & Dr. Roy Perryman University of East London, UK School of Electrical and Manufacturing Engineering Prof. Ján VITTEK & Dr. Juraj ALTUS University of Žilina, SK University of Žilina, SK Department of Electric Traction and Energetics Department of Electric Traction and Energetics Prof. Stephen J. DODDS & Dr. Roy Perryman University of East London, UK School of Electrical and Manufacturing Engineering FORCED DYNAMICS CONTROL OF INDUCTION MOTOR WITH SELECTABLE DYNAMICS FORCED DYNAMICS CONTROL OF INDUCTION MOTOR WITH SELECTABLE DYNAMICS University of East London 1999

FORCED DYNAMICS SPEED CONTROL of EL. DRIVES with Induction Motors u Application of: u u block control principle u u linearising function u u pseudo-sliding mode observers for angular speed estimation u u filtering observer including load torque estimation u Achievements: u u speed control without shaft sensor u u closed-loop dynamics for speed control chosen to suit particular drive application u u enhanced reliability of whole electric drive u Application of: u u block control principle u u linearising function u u pseudo-sliding mode observers for angular speed estimation u u filtering observer including load torque estimation u Achievements: u u speed control without shaft sensor u u closed-loop dynamics for speed control chosen to suit particular drive application u u enhanced reliability of whole electric drive Research CO-ORDINATION Prof. Stephen J. DODDS University of East London School of Electrical and Manufacturing Engineering Department of Electrical & Electronic Engineering Longbridge Road DAGENHAM, RM8 2AS United Kingdom

BASIC PRINCIPLE nonlinear plant i.e., specified closed-loop system u y y MOTIONSEPARATION LINEARISING FUNCTION nonlinear plant uy nonlinear control law linear and de-coupled closed-loop system with prescribed dynamics

MODEL OF MOTOR AND LOAD rotor magnetic flux linkage stator currents stator voltages motor torque rotor speed stator, rotor and mutual inductances stator and rotor resistances expressed in stator-fixed frame

CONTROL LAW DESIGN SIMPLIFICATION OF CONTROL PROBLEM BY INNER/OUTER CONTROL LOOP STRUCTURE r  inner-loop sub-plant outer-loop sub-plant master control law slave control law observers I inner loop outer loop U d   d  d   r I Rotor speed and rotor magnetic flux norm are demanded values

MASTER CONTROL LAW independently controls rotor speed and magnetic flux norm with first order dynamics and time constants, T1 and T2 linearising functions motor equation desired closed-loop equation master control law motor equation desired closed-loop equation

Acceleration Demands for Acceleration Demands for Three Various Dynamics 1. Constant Acceleration 3. Second Order Dynamic 2. First Order Dynamic

SET OF OBSRVERS FOR STATE ESTIMATION AND FILTERING is based on motor equations eliminate Drift Corrections algorithm is used for final magnetic flux filtering 1.Rotor Flux Estimator

Pseudo-Sliding Mode Observer and Angular Velocity Extractor slope K I motor equationUI I * (not used directly) -v For classical sliding -mode observer:- For pseudo sliding -mode observer:-,, angular velocity extractor

3. Filtering Observer Rotor angular velocity and load torque observer

Overall Control Systems Structure

Comparison of Control System Response and Demanded Response The actual system response is compared with the simulated output of the ideal speed response of prescribed dynamics.  theor U d U qdem U d Control Laws Power Electronics Induction Motor and Load II dq, UU dq,  dem  r  s T Ideal closed-loop system behaviour U q

Experimental Results for Induction Motor Drive Driven by First Order Dynamics Experimental Bench of East London University, Results: Daniel Vysoudil, AD Developments, Milton Keynes, UK

Experimental Results for Constant Acceleration

Experimental Results for First Order Dynamics

Experimental Results for Second Order Dynamics

Second Order Dynamics and Various Damping Factor underdumped system  =0.5 overdumped system  =1.5 critically dumped system  =1 a) b) c)

Various Prescribed Dynamics including MRAC a) constant torqueb) first order dyn.c) second ord. dyn.

Conclusions and Recommendations u A new approach to the control of electric drives with induction motors, based on feedback linearisation has been developed and experimentally proven. u Three various prescribed dynamics to speed demands were achieved. u Further research will focus on the application of the new approach to: u a) high power electric drives, including magnetic saturation and high speed applications, and u b) enhancement of control system for outer loop based on MRAC or SMC to improve precision of control.