1. iDRIVE iDRIVE Single-Phase Powered Induction Machine Drive for Residential Applications The Future Energy Challenge Energy Challenge in the Home April 29, 2004 Power Affiliates Program Presented by: Brett Nee Jonathan Kimball • Sponsored by: • Grainger Center for Electric Machinery and Electromechanics • National Science Foundation • California Energy Commission • In kind support from: • Emerson Motor Company

2. Overview • Future Energy Challenge’s Motivation • Design Specifications • UIUC’s solution: the “iDRIVE” • Competition Results • 2005 Future Energy Challenge Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

3. Motivation • Motors account for approximately 64% of the U.S. electrical use • Approximately 1 billion motors in the U.S. use over 1700 billion kWh/yr • 90% of the motors are less than 1 hp in size, and account for approximately 10% of the electricity consumed by the motor population • This translates to 170 billion kWh/yr Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

4. Motivation • Each 1% improvement in motor and drive efficiency results in: • 1.7 billion kWh/yr of energy saved • An equivalent of 6 –10 million tons of displaced coal/yr • 15 – 20 million tons less CO2 released into atmosphere/year • Over $1 billion energy cost saved/yr Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

5. 2003 FEC Requirements • Create a Motor and Drive System • Motor System Specifications: • Output power range 50W - 500W (<1HP) • Motor Speed ranges from 150RPM - 5000RPM • Efficiency > 70% • Power Factor > 0.8 • Operate from a single phase 120 Vac source Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

6. The iDRIVE PFC Boost Rectifier Hex-bridge Inverter Induction Motor Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

7. iDRIVE – PFC Boost • Specifications • 200 V dc bus with +/- 10 V ripple • >95% Efficiency • Power Factor≈1 • Output Power: 80W - 800W Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

8. iDRIVE - Inverter • Characteristics • dc to ac conversion (three-phase) • Transfer’s power from PFC stage to the induction motor • >95% Efficiency • Volts per Hertz motor control strategy using Harmonic Elimination Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

9. Hamonic Elimination 3rd – 13th harmonics eliminated Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

10. iDRIVE – Induction Motor Why a new design? • Low efficiency of standard machines. • Machines are not designed specifically for high efficiency with drives. • Need a different approach to meet the specifications. Different performance criteria can be applied: • No line-starts. • Motors operate only in low slip regime. Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

11. System efficiency Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

12. 2003 FEC Competition Results • Competition in Raleigh, NC. (May 2003 ) • 4 finalist teams, 1 semi-finalist • Testing facilities provided by Advanced Energy • University of Illinois • 2nd place overall ($7500) • Best Technical Presentation ($2500) Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

13. 2003 FEC Team Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

14. 2005 FEC Team Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

15. How do we build a winning system? • Everything must work • Should have plenty of time for system integration • Must achieve higher efficiency • Must maintain low cost • Must innovate • Potentially follow multiple paths Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

16. Motor Concepts • PMSM? Investigate • Cost issues • Induction Motor • Needs to be a lower slip design • Investigating exterior rotor for higher inertia Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

17. Topology Concepts • Boost PFC • Well-known industrial solution • Ideal for unity power factor • Buck PFC • Relatively untried • Possibly more passives? • Lower voltage stresses on semiconductors • Block diagram doesn’t change Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

18. Control Issues • Use inertia of motor • “Free” energy storage element • May displace capacitive energy storage • Need to address stability and instantaneous power flow • Otherwise shape current • Meet letter of specification, 0.8 PF • May be able to meet spec at a lower cost Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

19. Example Waveforms:Unity PF vs. 0.8 PF Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

20. 2005 Future Energy Challenge • Course offering ENG 491 fall and spring • 18+ students currently involved • Mechanical Engineering • Electrical Engineering • Grad students will drop off as undergrads come up to speed • Students will be organized into sub-teams • Replaces senior design requirement for EEs Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign

21. Summary • Competed effectively in 2003 Future Energy Challenge • Have several good ideas to build on, several lessons learned • Assembled a strong team to develop these ideas into a winning entry in 2005 Future Energy Challenge Grainger Center for Electric Machines and Electromechanics University of Illinois at Urbana-Champaign