P12026: Transcutaneous Power Transmission Team Members Nooreldin Amer Michael Carozzoni William Chan Naveen George Devin Prescott Paul Slagle

Presentation Outline  Project Description  Review of Customer Needs, Engineering Specifications, and House of Quality  Power Circuit for Motor  Armature/Motor Casing CAD  Receiver/Generator Casing CAD  Generator Selection  Power Transmission Test Data  Rectifier Circuit  Review of Risks  System Interface  Bill of Materials  MSD II Quarter Schedule

Project Description  T eam is currently researching and developing a module for transcutaneous (through the skin) power transmission. Our project involves the transmission of power through a gap using passive magnetic coupling. This unit has potential as a medical device, and is intended as a proof-of-concept for future application in ventricular assist devices (VAD).

Customer Needs Customer Need # ImportanceDescriptionComments/Status CN19 Transmit power wirelessly "Functional prototype paired motor and generator set with passive magnetic coupling." "Delivered system must be “sized” to be able to yield 100 watts at the motor (receiver)." CN29 Lasts long and is reliable "Estimated design life of 99% reliability at 10+ years with 95% confidence." CN3 9Safely implantableBio-compatible and low heat generation CN43Light "System weight less than 1 pound." CN53Small "Inner and outer components of the system must each be the size of a hockey puck or smaller." CN63Contained Shell containing device to prevent unwanted mass or energy transfer CN7 3Comfortable Minimize compressive pressure on tissue Importance: Sample scale (9=must have, 3=nice to have, 1=preference only).

Engineering Specifications

House of Quality

Power Circuit ComponentPart Rectifier400V 6A Bridge Rectifier Transformer120VAC to 12VDC 0.5A LM781212V output

Test Bench

Parallax BASIC Stamp 2 Module On-board flash Vin of 5.5V to 15V Cheaper than the Arduino Microcontroller Current members experienced in programming

Sample BASIC Code  ' {$STAMP BS2}  ' {$PBASIC 2.5}   FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 150 PAUSE 20NEXT  FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 250 PAUSE 20NEXT  FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 350 PAUSE 20NEXT  FOR counter = 1 TO 50 %start up gradual speed PULSOUT 13, 450 PAUSE 20NEXT  DO  PULSOUT 13, 650 %Full speed  PAUSE 20  LOOP   END

DK-LM3S-DRV8312 After comparing the DRV8312 to the Phoenix Motor Controller from Castle Creations, the DRV8312 has more options and better headroom with supply voltages up to 50V. This also has a higher PWM operating frequency of up to 500 kHz. This is a more robust controller and a better fit.

Case Material PVC Material Properties

Outside Sub Assembly Preliminary Model Motor (Blue): EC-i 40 Brushless Outside Shell(Red/Yellow): PVC Shaft Mount (Green): Aluminum Armature (Orange): PVC Magnets (black/red): Neodymium Motor Mount (Grey): PVC Length: 2in OD: 3in Weight: 0.75lb Max RPM: 9390 Number of Magnets: 6

ANSYS Simulation Armature/Receiver PVC Material Properties used for ANSYS Density1300kg/m^3 Modulus of Elasticity2.90E+09MPa Poisson Ratio0.41 Yield Strength51.5MPa RPM: Material: PVC Max Stress (12 Mag)=8.72 MPa (Pass) Max Stress (6 Mag)= 8.88 Mpa (Pass)

Receiver CAD Model Height: 35.5 mm [1.4 in] Diameter: 76.2 mm [3 in] Gear Ratio: 3.09:1, 30mm Pitch Helix Epoxy Sealed, USP Class VI

Receiver CAD Model

Tooth Profile

Receiver CAD Model

Receiver Sealing

Motor Efficiency

Generator Efficiency

MATLAB Implementation

MATLAB (cont’d)

Generator Selection  Maxon EC22, brushless, 100 Watts, sterilizable  Chosen for Operating point at 8.07 mNm and rpm Low heat dissipation (0.56 High power output (31 High operating speed (max. 60,000 rpm) High max. ambient and max. permissible winding temperature (135°C and 155°C, respectively)

Generator Comparison EC 16EC 22s Heat [W] Power [W] Cost [USD] Size [mm]16x5622x62.7 Max Ambient Temp [°C] Operating Torque [mNm] Operating Speed [rpm] No Load Speed

Magnetic Simulations

Armature/Receiver Testing

Three Phase Rectifier Circuit

Three Phase Rectifier Output Waveform

Output Voltage Regulator

Combination of Rectifier and Voltage Regulator

Review of Risks IDRisk ItemEffectCause Likelihood Severity Importance Action to Minimize RiskOwner Describe the risk briefly What is the effect on any or all of the project deliverables if the cause actually happens? What are the possible cause(s) of this risk? L*S What action(s) will you take (and by when) to prevent, reduce the impact of, or transfer the risk of this occurring? Who is responsible for following through on mitigation? 1 High Heat GenerationNot meeting specifications, Low generator efficiency, improper heat dissipation,339 Research into generators, dissipating heat properlyDP 2 High Operating RPM failureUnsafe testing conditionPower requirements236 Extra layer of safety during testing, gearingDP 3 Breakdown Torque/SlippageLose transmission of power Large air gap, weak magnet strength,236 Ramp-up algorithm, fail-safe mechanismWC 4 Low Power Transmission Not meeting power transmission requirement Heat specification causing a bottleneck326 Research into generators, proper heat dissipationMC 5 Low Motor Efficiency Possible too much heat generation, not meeting other specifications Lack of research into motors,224Do research regarding motor,NG 6Large deviceNot meeting specification, Trying to meet specification, not enough research224 Research components, negotiate with customer,PS 7 Failure of parts due to TransienceHigher stressGoing from 0 to x RPM,112 Ramp-up algorithm, factor of safetyNA Likelihood scaleSeverity scale 1 - This cause is unlikely to happen1 - The impact on the project is very minor. We will still meet deliverables on time and within budget, but it will cause extra work 2 - This cause could conceivably happen 2 - The impact on the project is noticeable. We will deliver reduced functionality, go over budget, or fail to meet some of our Engineering Specifications. 3 - This cause is very likely to happen3 - The impact on the project is severe. We will not be able to deliver, or what we deliver will not meet the customer's needs.

Interface with Final dimensions of generator and motor from (housing) provides 2 interior thermocouples and provides access to them provides hall effect sensors and provides access to them provides power to the hall effect sensors and generator side provides access to measure on both input and output

Interface with MeasurementUnit of Measure12022 Measurement Range12026 Operating Range Input Power to MotorW Output Power from GeneratorW Thickness of Transmission Materialm Contact ForceN External Motor Temperature°C Internal Generator Temperature°C External Generator Temperature°C Generator Housing TorqueN-m0-1 Motor RPMRPM k rpm Generator RPMRPM k rpm

Bill of Materials

Purchasing

Schedule for MSD II