Chengbin Ma Background: Motion Control and Mechatronics Area: EV motor and motion control Energy aware control, Vehicle dynamic control Employment: Aug. 2008-Pre: Assistant Prof., UM-SJTU Joint Institute; Joint Faculty Position in M. E. School, SJTU Nov. 2006-Mar. 2008: Post-doctor, UC Davis, USA Oct. 2004-Oct. 2006: R&D researcher, FANUC Limited, Japan Education: Sep. 2004: PhD, Dept. of E. E., Univ. of Tokyo Sep. 2001: M. A., Dept. of E. E., Univ. of Tokyo July. 1997: B. S., Dept. of Automation, East China Univ. of Science and Technology Conventional Vector Control Maximum Torque Control q axis d axis Field-weakening Control q axis Maximum Efficiency Control i a i q L d i d Direct Torque Control 0 L q i q Sensorless Control i d a a 0 Pn aiq Pn ( Ld d axis T i L ) i q i d q
Energy-aware Embedded Systems Energy consumption has become a major design issue for modern embedded systems especially battery-operated portable devices. S. Hua and G. Qu, "Approaching the Maximum Energy Saving on Embedded Systems with Multiple Voltages", Proceedings of the International Conference on Computer Aided Design (ICCAD 03) Dynamic Voltage Scaling Dynamic voltage scaling (DVS): varies the clock frequency and supply voltage according to workload at run-time to reduce dynamic power and save energy. The highest energy efficiency can be achieved for time-varying computational loads if voltage can be varied arbitrarily. P C L V 2 dd : switching activity : load capacitance C L V dd : supply voltage f : clock frequency f P. Marwedel, "Embedded Systems", Univ. Dortmund, Informatik 12, 2003
Losses in E-drive system Motor: Iron Loss + Copper Loss Inverter: Switching Loss + Conductance Loss T. Ogura,J. Itoh, "Evaluation of Total Loss of Both an Inverter and Motor Depending on Modulation Strategies", Linear Drive Committee, IEEJ, 2009/12/17 Examples of Applications Dynamic Voltage Scaling in Toyota Prius
Examples of Applications (Cont.) Development of a inverter to decrease loss for electric vehicle motor (Mitsubishi Heavy Industry Tech. Report VOL.45 NO.3: 2008) DVS vs QoS in EVs Quality of Service (QoS) is always a primary concern in the development of energy-aware control systems. Avoidance of torque variations and noises must be guaranteed during the voltage/frequency transitions under various dynamic EV driving conditions. Detailed investigations and research are needed to further explore the advantages of DVS control in EV applications. Analogy of biological blood systems: Different supply to different regions High pressure: High pulse count and High activity Low pressure: Low pulse count and Low activity
Interactive Analysis Primarily investigated by Prof. Ma when worked in Fanuc Limited, Japan (Year 2004~2006) A full electric drive system simulation platform is desired to improve the accuracy of simulation, enhance the reliability of design, shorten development period, etc. Interactive Analysis (Cont.) Key technologies for electric drive systems: materials, motor design, power electronics, control, etc. EX. high accurate simulation by FEM motor model + PE drive circuit model + Control algorithm blocks Power Electronics (inverter, etc) Finite Element Method (motor design) Electric Drive System (Motor, Drive Circuit and Control) Control Strategy (DSP, FPGA based) Materials (iron core, magnet, etc)
Interactive Analysis (Cont.) Tools for component-level simulations Motor Circuits Control Interactive Analysis (Cont.) A case study (PSIM [circuits and control]+jmag [motor]): Drive circuits Motor Control "MagCoupler Module", TM003-002-282_Ver1.0, Myway Co. Ltd, Japan
Interactive Analysis (Cont.) A case study (Cont.) JMAG FEM-based Motor Model PSIM Ideal Motor Model 3-phase current Motor torque 3-phase current Motor torque time time Torque ripples caused by motor structure is reproduced. "MagCoupler Module", TM003-002-282_Ver1.0, Myway Co. Ltd, Japan Successful stories: Interactive Analysis (Cont.) 1. YASKAWA Electric (YASKAWA NEWS No.294) - Investigate detailed behaviors before real integration of the whole mechatronic systems; therefore, enable the optimized design. Servo driver design Motor design
Interactive Analysis (Cont.) Successful stories: 2. MITSUBISHI Electric (MITSUBISHI NEWS 2/16/2011) - By using the interactive analysis of drive/control circuits and motor magnetic circuits, the world s most compact power-steering electric motor is developed with 50% volume and 70% weight of the previous motor with same power. Successful stories: Interactive Analysis (Cont.) 3. Ishikawajima-Harima Heavy Industries Co., Ltd (Report Vol.47 No.2 ( 2007-6 )) - Electromagnetic Field-Circuit interaction analysis is conducted for a highspeed PMSM motor. The simulation results are well verified by experiments with high accuracy. Back-EMF Motor Drive Voltage Motor Current Simulation results Experimental results