Transcript Schneider Electric Current Sensor

Geoff Bennett Miles Hancock Drew Jennings

Problem Description
 Novel Current Sensor
 Transmission Line Application
 Design Specifications
 Coreless
 Isolated Detection

Deliverables
 AC Current Sensor
 Sensor Designs
 Testing Data
Current Technologies
Rogowski Coil
Hall Effect Sensor

Emerging Technology
 Used in Hard Drives
 Recently Commercially Available
 Proven in other applications
 So How Does it work?
Electron Spin direction changes in the direction of the applied magnetic field
http://mrsec.wisc.edu/Edetc/IPSE/educators/activities/gmr.html
R1(GMR)
EMI Shielding
 Physical layout of GMR’s
 GMR biasing with current trace

1
2
a1
a2
a3
a4
GMR
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
Flux Collector
b1
b2
b3
b4
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
5
6
7
8
Conductor runs on top of GMR's. This is
designated by the doted lines.
3
4
GMR
Flux Collector
Current
Bias
Digital Signal Processing
True RMS calculation
 Real-time digital filtering
 Hysteresis calibration

http://www.ifw-dresden.de/institutes/imw/sections/26/magnetic-films-folder/hard-magnetic-films/nd-fe-b-films
Miles
Hancock
Geoff
Bennett
Rogowski Coil
Hall Effect
MEMS
Bill of Materials
Part Ordering
GMR
Faraday Effect
Radical Ideas
Timeline
Physical Design
Filter Design
Noise Correct
Magnetometers
Signal Analysis
Idea Matrix
Drew
Jennings
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

Why is it a good design?
 Cost, Safety, Size, Installation, Accuracy

Additional Functionality
 Power Calculation
 Very High Current Systems
GMR
Applied
Field
1
2
a1
a2
a3
a4
GMR
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
Flux Collector
b1
b2
b3
b4
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
5
6
7
8
Conductor runs on top of GMR's. This
is designated by the doted lines.
3
4
GMR
Flux Collector
Current
Bias
1
2
a1
a2
a3
a4
GMR
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
Flux Collector
b1
b2
b3
b4
5
1
3
2
7
4
6
8
a1
a2
a3
a4
GMR
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
GMR
Flux Collector
Flux Collector
b1
b2
b3
b4
5
6
7
8
Conductor runs on top of GMR's. This
is designated by the doted lines.
3
4
GMR
Flux Collector
Current
Bias