Smart Surge Protector
Team MembersJason Long & Billy Gates, Jr.
Professor Stephen E. Saddow, Advisor
Motivation Most residential surge protection devices fail without warning.
Some have indicator lights that are difficult to see.
A smart surge protection device that reports the status of the surge protection element (varistor) to the user via a computer interface.
A GUI (Graphic User Interface) will be used to report the status
to the user after reading the status of the monitoring circuit.
Team Members
JasonLongJasonLong Billy J Gates,Jr.Billy J Gates,Jr.
Dr. S. E. SaddowDr. S. E. Saddow
Team OrganizationBilly J Gates, Jr. Monitoring interface Presentation organization Computer program Web Page Executive Summary Test Specifications Objective
Jason Long Requirements Objectives References Web Page Problem Statement Surge Protection circuit
How to observe the protection device state?
1. LED’s
Are not always visible to user
2. Alarms
Are often ignored by user
3. Our design Give the user a computer prompt of the status of the device as it reaches the end of its lifetime.
Abstract A monitoring surge protection device that reports the
status of the surge protection circuit (varistor) to the computer.
A GUI (Graphic User Interface) will be used to report the status to the user, by reading the status of the monitoring circuit.
Objective 1. Test Source voltages: The Surge Protection Device (SPD) will operate from any standard 125V three-prong receptacle outlet that is designed for 120 VAC 60Hz. 2. Fire Standards: The device will meet all the National Fire and Safety Code and the National Electrical Codes. 3. Physical Packaging: We are not so much concerned with the physical packaging at the moment, although we know the design will be contained in a molded plastic case. The main concern will be getting the design to work. 4. Monitoring Time: We will check the status of the varistor for any changes caused by an over-voltage or over-current every 1s.
Objective
5. Transient Voltage Surge Suppression: The SPD will be designed to suppress a continuous transient voltage of 135V AC.
6. Clamping Voltage: “Clamping” is the term used for the process whereby surge protection devices reduce or attenuate transients and limit the surges reaching the protected load to a specific lower voltage level. The lowest clamping voltage recognized by United Laboratories (UL) is 330 V in the UL1449 standard. Rise time for the voltage must be within the 8s (microseconds), and with a 20s trail off. 7. Peak transient current: The SPD will be able to handle a peak transient voltage of 1200 Amps. Rise time for the current must be within the 8s (microseconds), and with a 20s trail off.
Objective
8.
8. Operation Indicator (Graphical User Interface): Our SPD operation indicator will be a graphical user interface. The graphical user interface will give the user the number of times the SPD has been placed in it protection mode (against over- voltage and over-currents) and the number of times the SPD has before the device fails. This information will be gather via a RS-232 serial port.
9. Surge Protection: The SPD will protect against transient voltage surges line to neutral, line to ground, and neutral to ground.
10. Measuring circuit: This circuit will trigger if an over-current or over- voltage thru the varistor. Triggering a counter that will hold the number of times the varistor has been activated for protection. We will use a battery to power the counter in the event of power loss.
Approach Computer Program
C++
Simulation PSPICE & Electronics Workbench
Hardware Varistor
RS-232 interface counter
N
L
G
ENERGY DISAPATED AS
HEAT DURING CLAMP
RESISDUAL TRAVELS ON TO LOAD
355 V CLAMPING LEVEL
TRANSIENT RESIDUAL SHUNTED TO NEUTRAL
1000 V, 100A
100 KHZ
SINGLE SPD COMPONENT
LOAD
TRANSIENT CURRENT IS SHUNTED L-N BY SPD COMPONENT
MONITORING CIRCUIT
PEARSON COIL
Design
4.
DesignSMART SURGE
PROTECTION DEVICE
SURGE MONITORINGCIRCUIT
METAL OXIDE VARISTOR
GRAPHICAL USERINTERFACE
C++ COMPUTERPROGRAM
PEARSON COILSAND COMPARITOR
RS-232PORT
4.
ComputeComputerr
Surge Surge ProtectoProtecto
r r
Monitor Monitor circuitcircuit
Design
DesignSurge Protection device This part of the circuit will consist of a varistor that will go into its active mode when an over-voltage or over-current occurs.Monitoring Circuit This part of the will trigger when a over-voltage or over-current occurs. To detect the over-voltage or over-current will sample the operation of the varistor when it is in its active mode.Counter The counter will be incremented each time the varistor is in it active mode. Computer Program(GUI) The program will have a preset value for the counter and it will check
the counter for the maximum allowed count and warn the user by prompting the
user with a visible icon on the computer screen.
Design
METAL OXIDE VARISTOR
PEARSON COIL
SURGE MONITORINGCIRCUIT
GRAPHICAL USERINTERFACE
Maximum Continuous Voltage RMS = 135 Vac, Maximum Transient Energy = 10 JoulesPeak Transient Current = 1200 amps, Maximum Clamping Voltage = 355 V, Transient Power Dissipation = .25 W
Maximum Peak Current = 2000 amps, Useable Rise Time = 20nsMaximum RMS Current = 25 amps
Op-amp, comparator, and current meter This part of the will trigger when a over-voltage or over-current occurs. To detect the over-voltage or over-current will sample the operation of the varistor when it is in its active mode.
C++ Program The program will have a preset value for the counter and it will check the counter for the maximum allowed count and warn the user by prompting the user with a
visible icon on the computer screen.
Test Specifications Circuit Simulations
Used to test component design
Software Software used to check the status of device
Test SpecificationRequirements SPD Surge
TestMonitoring Circuit Test
C ++ Simulation
Active Modes Fire Safety Code
Pspice Simulations
Input voltages
• • • •
• Fire Standards
•
Physical Packing
•
Transient Voltage Suppression
•
•
• Clamping Voltage
• •
•
• Overload Protection
• •
• Operation Indicator
• •
•
• Monitoring
Circuit
•
• GUI
•
Acknowledgements We would like to thank Dr. Stan
Saddow, our advisor for his help in our design project.
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