Synchronous Motor Drive Control System with Prescribed Closed-Loop Speed Dynamics Dodds, J., Stephen*, Vittek, Ján** *University of East London, School of Computing & Technology, UK **University of Žilina, Faculty of Electrical Engineering, Dept. of Power Electrical Systems, SK

Model of Permanent Magnet Synchronous Motor Non-linear differential equations formulated in the magnetic field-fixed d,q co-ordinate system describe the permanent magnet synchronous motor and form the basis of the control system development.

Control System Structure For PM Synchronous Motor outer loop sub-plant inner loop sub-plant Master control law estimator and observers slave I U inner loop outer loop Idem SJD

Complete control structure of electric drive with synchronous motor Transf. dq / a_b and a,b / a,b,c Master control law SMPM Slave control law abc / a b a,b / d,q Angular velocity Extractor Discrete two phase oscillator Mg. flux calculator Sliding mode Observer Filtering observer iq id ud uq ua,b,c vd_ekv vq_ekv ia ib ua ub uc ib_dem ia_dem ic_dem id_dem iq_dem ic POWER electronics

Discrete Time Two-Phase Oscillator The discrete time two-phase oscillator produces the transformation matrix elements, needed for the transformation blocks. where the new transformation matrix elements are equal to and .

Master Control Law linearising function motor equation demanded dynamic linearising function vector control terms demanded values of the current components motor equation

Acceleration Demands for Three Various Dynamics First Order Dynamic Second Order Dynamic Constant Acceleration

Slave Control Law Proportional High Gain Slave Control Law Bang-Bang Slave Control Law A High Gain Proportional Control Law with Voltage Saturation Limits was used for simulation Bang-Bang Control Law Operating in the Sliding Mode (switching strategy for two-phase version is satisfactory determined).

The Sliding Mode Observer and Angular Velocity Extractor The basic stator current vector pseudo sliding-mode observer is given by: The required estimates is equivalent values where is high a gain unfiltered angular velocity estimate can be extracted For the purpose of producing a useful formula for perfect constant parameter estimates may be assumed:

The Filtering Observer Filtered values of and are produced by the observer based on Kalman filter VJ where: needs adjustment of the one parameter only.

Current sensors are as follows:- LEM LTA 50P/SPI. EXPERIMENTAL RESULTS Electric drive with synchronous motor consists of synchronous machine with nominal parameters: , , P = 4 , , , . Parameters of IGBT FUJI 6MBI-060 are as follows:- nominal voltage: 600 [V] , nominal current: 6x10 [A]. Current sensors are as follows:- LEM LTA 50P/SPI.

Measured Results for Synchronous Motor with Constant Acceleration Complex Current Current v. t 2 2 -2 -2 -2 Complex Mg. Flux 2 Mg. Flux v. t 0.5 0.2 0.2 -0.2 -0.2 -0.2 Observed Values 0.2 Rotor Speed 0.5 100 100 50 50 -50 0.5 1 -0.5 0.5 1 T1 = 0.1 s , wd = 60 rad/s

1 - angular velocity, 2 - current in phase A Measured Results for Synchronous Motor with Constant Acceleration - osciloscope screen 1 - angular velocity, 2 - current in phase A T1 = 0.1 s , wd = 60 rad/s

Experimental results for idle running synchronous motor and first order speed demand . -5 5 Complex Current 0.4 Current v. t -0.2 0.2 Complex Mg. Flux Mg. Flux v. t 0.5 1 -50 50 100 Observed Values -0.5 Rotor Speed T1 = 0.05 s , wd = 80 rad/s

1 - angular velocity, 2 - current in phase A Experimental results for idle running synchronous motor and second order speed demand - osciloscope screen 1 - angular velocity, 2 - current in phase A Tset = 0.15 s , wd = 80 rad/s

Experimental results for idle running synchronous motor and second order speed demand -5 5 Complex Current 0.4 Current v. t -0.2 0.2 Complex Mg. Flux Mg. Flux v. t 0.5 1 -50 50 100 Observed Values -0.5 Rotor Speed Tset = 0.15 s , wd = 80 rad/s

1 - angular velocity, 2 - current in phase A Experimental results for idle running synchronous motor and first order speed demand - osciloscope screen 1 - angular velocity, 2 - current in phase A T1 = 0.05 s , wd = 80 rad/s

Experiments with 2nd Order Dynamic for Various Damping -0.2 0.2 0.4 0.6 0.8 60 -10 10 20 30 40 50 z=0.5 z=2 z=1 Tsettl=0.3 s , wd = 40 rad/s

Experimental Results for Synchronous Motor Drive Constant Acceleration First Order Dynamic Second Order Dynamic wd= 600 rpm, Tramp= 0.05 s 800 rpm, Tsettl= 0.3 s Zilina 1998 Control of the angle between rotor flux and stator current vectors

Conclusions and Recommendations A new approach to the control of electric drives with permanent magnet synchronous motors, based on feedback linearisation has been developed and experimentally proven. Three various prescribed dynamics to speed demands were achieved. Further research will focus on the application of the new approach to enhancement of control system for outer loop based on MRAC or SMC to improve precision of control.