UVU Electrical Engineering Capstone Project

Easy, Simplified, Affordable Motor Protection (ESAMP)

Team Members: Jordan Littlefield and Dexton Graves

Faulty Advisor: Dr. Afsaneh Minaie

Poster for ESAMP

The purpose of this project was to develop and build a simple and affordable motor protection system using an ATmega328P microcontroller and a solid-state relayto reduce the risk of costly motor repairs and fire hazards. The system ismonitoring 3-phase currentsusing three current transformers, whose secondarycurrent produces avoltage across a burden resistorthat is sampled by the onboard ADC. The 3-phase voltagesare stepped down through parallel transformers, rectified, filtered, and sampled with the onboard ADC. The temperature of the motor is measured using a platinum resistance temperature device (PT-RTD) that has a resistance of 100Ω at 100Ω at 0°C. The speed of the motor is measured using a 20-hole encoder disk with a LM393 speed sensor module that has an infrared coupled diode. The microcontroller is programmed to control a solid-state relay with one of its digital output pins to turn the motor off when the system experiences any undervoltage, overvoltage, overcurrent, overtemperature, and overspeed. The system’s data is sent over the internet to the Blynk app where the user can see in real time the voltages and current of all three phases along with the temperature and speed of the motor. The Blynk app will remotely notify the user when the motor first starts up or if there were any restarts and notifythe user that the motor has been turned off. Testing was done by creating a voltage drop on the secondary side of the voltage transformers to simulate a voltage drop. The temperature sensor was also manually heated to simulate an increase in temperature. When these tests were done, there was a successful disconnection of the motor from the system and the user was notified through the Blynk app.

Students' Presentation