Analytical Solution of Optimized Energy Consumption of Induction Motor Operating in Transient Regime

The problem of energy optimization of induction motor (IM) using the concept of a Rotor Field Oriented Control (RFOC) can be treated by an Optimal Control Strategy (OCS). Using OCS, a cost-to-go function can be minimized and subjected to the motor dynamic equations and boundary constraints in order to find rotor flux optimal trajectories. This cost-to-go function consists of a linear combination of magnetic power, copper loss, and mechanical power. The Dynamic equations are represented by using a reduced Blondel Park model of induction motor. From the Hamilton-Jacobi-Bellman (HJB) equation, a system of nonlinear differential equations is obtained, and analytical solutions of these equations are achieved so as to obtain a time-varying expression of a minimumenergy rotor flux. Under RFOC, this analytical solution of rotor flux achieved maximum IM's efficiency and was implemented in transient torque. The current study discusses a saturation model with respect to the rotor flux, which has significant influence in the motor's parameters. A comparative study of simulation results given from conventional and optimized RFOC proves the presented strategy's validity and effectiveness.

[1]  A. V. Manzhirov,et al.  Handbook of mathematics for engineers and scientists , 2006 .

[2]  A. Polyanin,et al.  Handbook of Exact Solutions for Ordinary Differential Equations , 1995 .

[3]  Dong-Seok Hyun,et al.  Stator-flux-oriented control of induction motor considering iron loss , 2001, IEEE Trans. Ind. Electron..

[4]  R.D. Lorenz,et al.  AC induction servo sizing for motion control application via loss minimizing real-time flux control , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[5]  I.Ya. Braslavsky,et al.  Optimization of starting process of the frequency controlled induction motor , 2008, 2008 13th International Power Electronics and Motion Control Conference.

[6]  E. Rosu,et al.  The optimal control for position drive system with induction machine , 2009, 2009 13th European Conference on Power Electronics and Applications.

[7]  Li-Chen Fu,et al.  Nonlinear control of induction motor with unknown rotor resistance and load adaptation , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[8]  Hans P. Geering,et al.  Optimal control with engineering applications , 2007 .

[9]  Tze-Fun Chan,et al.  A rule-based acceleration control scheme for an induction motor , 2002 .

[10]  Carlos Canudas de Wit,et al.  Optimal torque control for current-fed induction motors , 1999, IEEE Trans. Autom. Control..

[11]  Frank L. Lewis,et al.  Optimal Control , 1986 .

[12]  R.D. Lorenz,et al.  Efficiency-optimized flux trajectories for closed cycle operation of field oriented induction machine drives , 1988, Conference Record of the 1988 IEEE Industry Applications Society Annual Meeting.

[13]  Z. Ishmatov,et al.  Energy consumption and losses calculation approach for different classes of induction motor drives , 2006, International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2006. SPEEDAM 2006..

[14]  Hong-Hee Lee,et al.  New approach to energy efficient control of induction motor drives , 2004, 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004.

[15]  Carlos Canudas de Wit,et al.  Nonlinear H2 and H∞ optimal controllers for current-fed induction motors , 1997, 1997 European Control Conference (ECC).

[16]  Zhihao Ling,et al.  Improved Efficiency Optimization for Vector Controlled Induction Motor , 2009, 2009 Asia-Pacific Power and Energy Engineering Conference.

[17]  Jeong-Ho Park,et al.  An EM‐based adaptive multiple target tracking filter , 2002 .

[18]  S. Taniguchi,et al.  A speed sensorless vector control of induction motor operating at high efficiency taking core loss into account , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[19]  R. Dhifaoui,et al.  Modelling and simulation of a double‐star induction machine vector control using copper‐losses minimization and parameters estimation , 2002 .

[20]  Robert D. Lorenz,et al.  Verification of enhanced dynamic torque per ampere capability in saturated induction machines , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.