Current Control for Synchronous Motor Drives: Direct Discrete-Time Pole-Placement Design

This paper deals with discrete-time models and current control methods for synchronous motors with a magnetically salient rotor structure, such as interior permanent-magnet synchronous motors and synchronous reluctance motors (SyRMs). The dynamic performance of current controllers based on the continuous-time motor model is limited, particularly if the ratio of the sampling frequency to the fundamental frequency is low. An exact closed-form hold-equivalent discrete motor model is derived. The zero-order hold of the stator-voltage input is modeled in stationary coordinates, where it physically is. An analytical discrete-time pole-placement design method for two-degrees-of-freedom proportional-integral current control is proposed. The proposed method is easy to apply: only the desired closed-loop bandwidth and the three motor parameters (Rs, Ld, Lq) are required. The robustness of the proposed current control design against parameter errors is analyzed. The controller is experimentally verified using a 6.7-kW SyRM drive.

[1]  R.D. Lorenz,et al.  Improved current regulators for IPM machine drives using on-line parameter estimation , 2002, Conference Record of the 2002 IEEE Industry Applications Conference. 37th IAS Annual Meeting (Cat. No.02CH37344).

[2]  G. Franceschini,et al.  Cross-saturation in synchronous reluctance motors of the transverse-laminated type , 1998, Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242).

[3]  F. Briz,et al.  Dynamic analysis of current regulators for AC motors using complex vectors , 1998, Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242).

[4]  Russel J. Kerkman,et al.  A New Synchronous Current Regulator and an Analysis of Current-Regulated PWM Inverters , 1986, IEEE Transactions on Industry Applications.

[5]  Joachim Böcker,et al.  Discrete-time design of adaptive current controller for interior permanent magnet synchronous motors (IPMSM) with high magnetic saturation , 2013, IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society.

[6]  J. Pontt,et al.  Design of fast and robust current regulators for high-power drives based on complex state variables , 2004, IEEE Transactions on Industry Applications.

[7]  Robert D. Lorenz,et al.  Deadbeat-Direct Torque and Flux Control of Interior Permanent Magnet Synchronous Machines With Discrete Time Stator Current and Stator Flux Linkage Observer , 2011, IEEE Transactions on Industry Applications.

[8]  Jean-Claude Alacoque.  Discrete-Time Modelling - Flux and Torque Deadbeat Control for Induction Machine , 2006, 2006 12th International Power Electronics and Motion Control Conference.

[9]  Lennart Harnefors,et al.  Modeling of Three-Phase Dynamic Systems Using Complex Transfer Functions and Transfer Matrices , 2007, IEEE Transactions on Industrial Electronics.

[10]  F. Briz,et al.  Analysis and design of current regulators using complex vectors , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[11]  Lennart Harnefors,et al.  Torque-maximizing field-weakening control: design, analysis, and parameter selection , 2001, IEEE Trans. Ind. Electron..

[12]  Brian D. O. Anderson,et al.  Design of multivariable feedback systems , 1967 .

[13]  David Naso,et al.  Discrete-Time Control of High-Speed Salient Machines , 2016, IEEE Transactions on Industry Applications.

[14]  Hans-Peter Nee,et al.  Model-based current control of AC machines using the internal model control method , 1995 .

[15]  Robert D. Lorenz,et al.  Discrete-time current regulator design for AC machine drives , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[16]  M. Bongiorno,et al.  Input Admittance Expressions for Field-Oriented Controlled Salient PMSM Drives , 2012, IEEE Transactions on Power Electronics.

[17]  Joachim Böcker,et al.  Control Realization for an Interior Permanent Magnet Synchronous Motor ( IPMSM ) in Automotive Drive Trains , 2011 .

[18]  L. Shieh,et al.  Transformations of a class of multivariable control systems to block companion forms , 1982 .

[19]  S. Hiti,et al.  Modified Current Control Schemes for High-Performance Permanent-Magnet AC Drives With Low Sampling to Operating Frequency Ratio , 2009, IEEE Transactions on Industry Applications.

[20]  Jan Melkebeek,et al.  Reciprocity relations for the mutual inductances between orthogonal axis windings in saturated salient-pole machines , 1990 .

[21]  R.D. Lorenz,et al.  Discrete-Time Domain Modeling and Design for AC Machine Current Regulation , 2007, 2007 IEEE Industry Applications Annual Meeting.

[22]  Tobias Geyer,et al.  Model Predictive Direct Torque Control: Derivation and Analysis of the State-Feedback Control Law , 2013, IEEE Transactions on Industry Applications.

[23]  Joachim Holtz,et al.  High-bandwidth current control for torque-ripple compensation in PM synchronous machines , 1998, IEEE Trans. Ind. Electron..

[24]  Gene F. Franklin,et al.  Digital control of dynamic systems , 1980 .

[25]  Gene F. Franklin,et al.  Digital Control Of Dynamic Systems 3rd Edition , 2014 .

[26]  Lennart Harnefors,et al.  Design and analysis of general rotor-flux-oriented vector control systems , 2001, IEEE Trans. Ind. Electron..

[27]  Seung-Ki Sul,et al.  A compensation method for time delay of full digital synchronous frame current regulator of PWM AC drives , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[28]  T. Ara,et al.  A method to calculate transient characteristics of synchronous reluctance motors considering iron loss and cross-magnetic saturation , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[29]  Toni Tuovinen,et al.  Current control for IPMSM drives: Direct discrete-time pole-placement design , 2015, 2015 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD).

[30]  M. Hinkkanen,et al.  Inclusion of magnetic saturation in dynamic models of synchronous reluctance motors , 2012, 2012 XXth International Conference on Electrical Machines.

[31]  R. E. Yates,et al.  State-feedback decomposition of multivariable systems via block-pole placement , 1983 .