Novel Current Sensor Schneider Electric

Geoff Bennett Miles Hancock Drew Jennings

GENERAL DESCRIPTION

Problem DescriptionNovel Current SensorTransmission Line ApplicationDesign SpecificationsCorelessIsolated Detection

DeliverablesAC Current Sensor Sensor DesignsTesting Data

LITERATURE REVIEW

Current Technologies

Rogowski Coil Hall Effect Sensor

DECISION MATRIX

GMR TECHNOLOGY

Emerging TechnologyUsed in Hard DrivesRecently Commercially AvailableProven in other applications

So How Does it work?

Electron Spin direction changes in the direction of the applied magnetic field

GMR TECHNOLOGY

http://mrsec.wisc.edu/Edetc/IPSE/educators/activities/gmr.html

GMR TECHNOLOGY

R1(GMR)

GMR TECHNOLOGY

CONCEPTUAL DESIGN

EMI Shielding Physical layout of GMR’s GMR biasing with current trace

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Current Bias

Conductor runs on top of GMR's. This is designated by the doted lines.

GMR

GMR

GMR

CONCEPTUAL DESIGN

True RMS calculation Real-time digital filtering Hysteresis calibration

Digital Signal Processing

HYSTERESIS CURVE

http://www.ifw-dresden.de/institutes/imw/sections/26/magnetic-films-folder/hard-magnetic-films/nd-fe-b-films

INSTRUMENTATION AMPLIFIER

MANAGEMENT SCHEDULE

Rogowski CoilHall Effect

MEMSBill of MaterialsPart Ordering

GMRFaraday EffectRadical Ideas

TimelinePhysical Design

Filter DesignNoise Correct

MagnetometersSignal Analysis

Idea Matrix

Miles Hancock

Geoff Bennett

Drew Jennings

DEVELOPMENT COSTS

Purchase Order

List # Device Digikey Part # Manufacturer Unit Cost Quantity Cost

1 EMI Casing 377-1604-ND Bud Industries $51.80 1 $51.80

2 Blackfin Ezlite Kit (DSP) ADZS-BF518F-EZLITE-ND Analog Devices $538.31 1 $538.31

3 Power Chip 296-22673-5-ND Texas Instruments $9.50 1 $9.50

4 GMR sensor 391-1002-ND NVE $6.08 15 $91.13

5 Prototyping Board 438-1025-ND Twin Industries $13.78 3 $41.34

6 Voltage reference LM285Z-1.2NS-ND National Semiconductor $1.05 1 $1.05

7 Instrumentation Amp INA118P-ND Texas Instruments $9.60 1 $9.60

8 Capacitor (470 pF) 399-4241-ND Kemet $0.28 20 $5.60

9 Capacitor (0.1 µF) P925-ND Panasonic $0.09 20 $1.82

10 Resistor (7.5 kΩ) 7.5KADCT-ND Yageo $0.62 20 $12.38

11 Resistor (100 kΩ) 100KADCT-ND Yageo $0.62 20 $12.38

12 Power Transistor IRFU3303PBF-ND International Rectifier $1.05 4 $4.20

13 Soldering Iron Tips PTS7-ND Cooper Industries $3.30 3 $9.90

Total: $789.01

Development Costs: $789.01

Production Cost: $256.63

CONCLUSIONS

Why is it a good design?Cost, Safety, Size, Installation, Accuracy

Additional FunctionalityPower CalculationVery High Current Systems

Production Cost: $256.63

GMR

Applied Field

CURRENT PROTOTYPE

CURRENT PROTOTYPE

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Current Bias

Conductor runs on top of GMR's. This is designated by the doted lines.

GMR

GMR

GMR

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

1234

5678

a1a2a3a4

b1b2b3b4

GM

R

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Flux Collector

Current Bias

Conductor runs on top of GMR's. This is designated by the doted lines.

GMR

GMR

GMR

QUESTIONS