Energy Systems Research at Oregon State University

1. Energy Systems Research at Oregon State University Annette von Jouanne, Ph.D., P.E. School of Electrical Engineering and Computer Science Oregon State University

2. Outline • Brief Overview of OSU’s main Energy Systems Lab – The Motor Systems Resource Facility (MSRF) -Capabilities -Example Recent Research and Testing Projects • Current Main Research Thrusts -NAVY LCAC (Landing Craft, Air Cushion) Hovercraft -Ocean Energy Research -Hybrid Electric Tank Power Quality

3. Motor Systems Resource Facility (MSRF) • A Machines, Drives, Power Electronics, Renewables and Power Quality Research and Testing Laboratory at OSU • Fully operational since 1996 • Founding Sponsors: • Electric Power Research Institute (EPRI) • Bonneville Power Administration (BPA) • US Department of Energy (USDOE) • Pacific Gas & Electric (PG&E) • Co-Directed by Drs. A. Wallace and A. von Jouanne

4. OBJECTIVES OF THE MSRF • Create a unique research and testing facility where our students can obtain an enhanced, hands-on industrial experience, while meeting the needs of the Energy Systems Industry. • Highly flexible capabilities: • converters, drives, power supplies, filters and controllers • motors, generators and renewables (can regenerate) • wide power and speed range • Highly efficient: only system losses dissipated.

5. MSRF CAPABILITIES

7. MSRF – Partial Aerial View

8. MSRF 300 hp Test Bed (with Hybrid Electric Vehicle Generator)

10. STRENGTHS OF THE MSRF

11. Navy STTR Phase I Contract: LCAC (Landing Craft Air Cushion) High Performance Hovercraft (with Chinook Power) Objectives Develop improved actuator systems for steering vanes in thrust engine exhausts, thus reducing the maintenance, complexity, and failure modes associated with conventional hydraulic systems.

12. Existing Technology to be Replaced(High maintenance Hydraulics) Major Specs: 1100lbs oper. thrust 5.1 inches of travel Speed: 5.5 inches/s Wt: 12lbs w/out fluid Solution: Replace hydraulic system with a Switched Reluctance Motor (SRM)/drive, operating as a linear actuator “screw” Ave LCAC is 16,000hp, (8,000hp propulsion, 8,000hp lift)

13. Mock-up Installation Drive electronics mounted inside of nacelle leg (for protection) Note: Vibration is a huge issue… Absolute resolver (as a direct reading sensor, would give redundancy) For fail-safe oper., would have “home sensor”, and two end-of-travel sensors SRM/leadscrew actuator

14. SRM/leadscrew actuator Roller Nut SRM Roller Screw Thrust Shaft See improvements in speed, thrust, maintenance, wear, lifetime and reliability when compared to the better known "power screw" and "ball screw" configurations

15. Why Choice of SRM/Drive • Has ideal characteristics for the combat environment • High power density • Robust Design (rotor is a simple stack of laminations, without any windings or magnets) • Fault tolerant (limp home capability, e.g. during loss of phase)

16. MOTOR SYSTEM CLASS CANDIDATES

17. RELUCTANCE MOTOR COMPARISON

18. + A B C D Vdc - MOTOR & POWER ELECTRONICS Classic Bridge Converter favored (importance of robustness/fault tolerance) 8/6 SRM - When a stator phase is energized, the most adjacent rotor pole-pair is attracted towards the energized stator in order to minimize the reluctance of the magnetic path. Therefore, it is possible to develop constant torque in either direction of rotation by energizing consecutive phases in succession.

19. DESIGN PROCESS FOR SRM

20. SRDaS (Switched Reluctance Design and Simulation) showing size/geometry specs. Dev. by Dr. Peter Rasmussen, Aalborg University, Denmark

21. FEA MAGNETIC FLUX VISUALIZATIONS (using Maxwell 2D) Aligned position Unaligned position

22. Leadscrew & Motor Calculations(115Vp/200V/400Hz)

23. SRM SYSTEM PHOTOS Rotor Stator 3ph, 120V, ½ hp Position detection by signal injection SRM controller

24. VERTICAL THRUST PLATFORM (SRM rigged to lift a load)

25. RESULTS OF VERTICAL THRUST PLATFORM A 140lb weight can be lifted with the setup (limited by this SRM/contr.), shows trend that thrust can be further improved (req. operating thrust is up to 1100lbs)

26. Research Thrust: Ocean Energy Extraction • It is estimated that if 0.2% of the ocean’s untapped energy could be harnessed, it could provide power sufficient for the entire world. • OSU is the Prime Location to conduct ocean wave energy extraction research: - Motor Systems Resource Facility (MSRF) - Hinsdale Wave Research Lab - Wave energy potentials of the Oregon coast.

27. Power from WavesAverage of 5 buoys off the Oregon coast over past 10 years (From National Data Buoy Center) Power from a wave is kW/m of crest length (distance along an individual crest)  = the density of sea water = 1025 kg/m3 g = acceleration due to gravity = 9.8 m/s/s T = period of wave (s) (averages 8s in the winter to 6s in the summer) H = wave height (m) (averages 3.5m in the winter to 1.5m in the summer)

28. Direct Drive Buoy (Current Focus) Simplify the current buoy technology Avoid hydraulic based units, looking at direct drive rollerscrew and linear PM gen. systems Increase lifespan and decrease maintenance Oscillating Water Column (Will also be fully investigated) Create novel approach Simplify the units, introduce modularity with flexibility Investigate Advanced Composite Materials Bring overall costs down Our Planned Devices and Goals Must be Survivable, Reliable, and Maintainablewith efficient and high quality power take-off systems

29. Oscillating Water Column Concept

30. Hydraulic AquaBuoy Prototype System (We’ll be developing the Power Take-off (PTO) system for this unit)

31. OSU is Currently Investigating Two Novel Direct Drive Buoy Approaches: Exploring Roller Screw Concept (allows increased Gen speeds) Permanent Magnet Linear Generator

32. OSU’s air gap wound, permanent magnet, linear generator buoy Uses the vertical motion of the waves to power a linear generator (shaft anchored to sea floor, floater moves armature coils relative to PM translator to induce voltages)

33. OSU’s air gap wound, permanent magnet, linear generator Translator, air gap, plastic tube (aqua), Armature coils (yellow), steel lamination The translator shaft has an alternating assembly of high permeability steel pole tip pieces (needed for the transfer and direction of flux) and high density Neodymium-iron-boron magnets The armature coils are spirally encased with electrical lamination steel (outer grey) to provide for flux coupling through the generator.

34. Armature Coils of the air gap wound, PM, linear generator Showing One Phase Constructional Section Translator, air gap, plastic tube (aqua), Armature coils (yellow), steel lamination The armature consists of a thin walled plastic tube (aqua) wrapped with copper magnet wire (yellow) forming eight individual coil sections spaced such that they are 90 degrees out of phase with each adjacent section (for two phase application).

35. Actual Armature (top) and Translator Shaft (below) Armature coils wrapped on plastic tube, using Al shaft for support Translator shaft (total 32cm long), alternating pole pieces and magnets (magnet poles opposed to double the available flux). The steel pole tip pieces are threaded for ease of assembly on nonmagnetic shaft. Magnets: N-35, Ni coating, outer dia. 45mm, inner dia. 20mm, thickness10mm

36. Actual Translator Shaft in Armature Armature shown with Aluminum casing around steel laminations

37. Direct Drive Buoy Based on a Novel Roller Screw Concept A float/spring will be attached to the nut, moving the nut up and down approximately 0.45m above and 0.45m below the equilibrium position as the water moves up and down. It is envisioned that a generator will be coupled to the end of the screw to be rotated by it. The up and down motion will make the screw rotate in a clockwise and counter clockwise direction, moving the rotor of the generator to generate electricity.

38. PM Synchronous Generator in Dynamic Reciprocating Mode Sine driven Speed/Wave Profile Enabled by Programmable Dyno -max speed avail. in given time (T =3.5s) is 262rpm clockwise to 262 counter cw Output line voltage and three-phase currents modulated by the speed of rotation, Showing correlation between min. and max. speeds and generator output power

39. Our Planned R&D Process Currently Funded Work • Initial research and development into the prototypes and power take-off (PTO) systems • Following the R&D we will experimentally simulate the electrical characteristics in the MSRF (generators, controllers and converters, PTO etc.), with regeneration back onto the utility grid Next Stage Plans with Future Funding • Build larger scale prototype models to test in the Hinsdale Wave Research Lab • Testing/demonstration of working devices off the Oregon Coast

40. United Defense Contracts • Research on the Power Quality issues involved with Hybrid Electric Tanks (has “highly sensitive” status, thus detailed discussion must be avoided) • Analyzing the harmonics on the main bus while considering multiple (proprietary) converter loads. (includes analytical open-form derivations, closed-form solutions, simulation and experimental verification, as well as investigation mitigation techniques)