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Sponsored by:

Schweitzer Engineering Laboratories, Inc.

Team Rush

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Team• Andrew King • Scott Henderson

• Mentor: Normann Fischer (SEL)• Advisors: Joe Law, Richard Wall• Consultant: Jared Mraz

Team Rush

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Overview• Purpose

• Need/Specs

• System Block Diagram

• Breakdown of Components

• Budget

• Plan/Schedule

• Priorities

Team Rush

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What’s the point?

Transformer failure is expensive

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Need• Bank of power electronics switches

• Energize at any point in the voltage waveform

• Three phase capability

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Specifications• Microprocessor Control

• Switches: withstand 400A peak

• Control three phases

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Specifications cont.• Zero detection circuit

• System accuracy: within 500μs

• Track voltage/current waveform

Budget not to exceed $3000.00

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Solution• Versatile microprocessor based system

• Power electronics switches

• Voltage and current monitoring

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Solution cont.• Modular for each phase

– Less Risk– Ease of troubleshooting– More easily adaptable

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0 Cross Detection• Methods Explored:

– Op-Amp Circuit– Comparator Circuit– Detection Through Software

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0 Cross Detection• Methods Explored:

– Op-Amp Circuit• Effective in Testing• Accuracy within 100-200μs

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0 Cross Detection• Methods Explored:

– Comparator Circuit• Less complicated than op-amp circuit• Accuracy reported to 1-2μs• Will test in near future

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0 Cross Detection• Methods Explored:

– Detection Through Software • Could require significant processor resources• Build capability into processor, explore at a later date

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Microprocessor• Considered:

– Rabbit– ARM– PSoC

• Best Choice: – PSoC

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Microprocessor• PSoC

– Capture and Compare– Flexible– Cheap

• Modularization• Limited Risk• Several available for experimentation

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PSoC• Programmable System On Chip

– Mfg. by Cypress Semiconductor– Mixed signal array

• 8-bit M8C microprocessor• 24 MHz clock speed• Analog and digital peripherals

– Constructed based upon needs• Building block architecture• Programmed with C

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Switching Device• Considered:

– Triac– Thyristor(SCR)– SCR Modules

• Best Choice: – IXYS SCR Module MCC-220

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Switching Device• IXYS SCR Module MCC-220

– Cheap– Back to back package– Easy to mount– Price: $136 each

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SCR Gate Driver• Considered:

– Enerpro– Applied Power Systems– Build it ourselves

• Best Choice:– Enerpro--Single Phase SCR Firing Board

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SCR Gate Driver• Enerpro--Single Phase SCR Firing Board

– Don’t have to build anything– Fires two SCRs– Possible source for 0 cross detection– Instantaneous Inhibit/Enable– Price: $269 each

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Heatsink• Considered:

– Purchase– Non-utilized heat sink belonging to the U of I

• Best Choice: – Non-utilized heat sink

• Slightly oversized but will work• Price: Free

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Mechanical Contactor• Cutler Hammer C25FNE350A

– 3 Pole 50A contactor– 110-120V AC Coil– Price: appx. $200.00

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Current Measurement• LEM HTFS 400-P/SP2

• Isolated/Hall effect device

• Price: $47.00 each

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Voltage Measurement• LEM CV 3-500

• Closed loop voltage transducer

• Price: currently unknown, approx. $70.00

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PCBs• Two per Phase

– Board 1--Processor/0 cross detect– Board 2—Sensor/Sensor Support

• Price: Appx. $800

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Budget– Initial Budget $3000

• SCRs (3) $408

• SCR Driver Boards (3) $810

• Contactor (1) $200

• Microprocessors (3) $450

• PCBs (6) $800

• Current Transducers (3) $150

• Voltage Measurement (3) $210

• Miscellaneous Equipment $100

– Total $3128– Amount Over Budget $128

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Plan/Schedule• Remainder of First Semester

– Order all purchasable components*– Work with loaner PSoC processor– Construct SCR/Driver/Contactor – Continue work on 0 cross detection

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Plan/Schedule• Second Semester

– Design/Build integrated PCBs– Integrate Microprocessor– Complete/Test entire system– Write paper for WCPRC

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Priorities (In order of importance)

• 1) Single phase switch

• 2) Priority 1—3 phase

• 3) Testing

• 4) Voltage/current monitoring

• 5) Residual flux measurement

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Any Questions?

Andy King

andrewking@vandals.uidaho.edu

Scott Henderson

scott.henderson@vandals.uidaho.edu

http://seniordesign.engr.uidaho.edu/2007_2008/rush/