Digital Twin of a Multi Function Protection Relay

This project is a multifunction protection numerical relay. In power systems protection relay are used to protect electrical equipment from faulty conditions such as short circuit current, under and over voltage, under and over frequency and phase reversal phase failure etc. There have bee

Project Title

Digital Twin of a Multi Function Protection Relay

Project  Area of Specialization

Internet of Things

Project Summary

This project is a multifunction protection numerical relay. In power systems protection relay are used to protect electrical equipment from faulty conditions such as short circuit current, under and over voltage, under and over frequency and phase reversal phase failure etc. There have been vast advancement in power protection relays in decades, from electromagnetic induction type (Mechanical) relays to solid state relays, the latest technology used in protection system are numerical relays, which are the part of new smart grid systems. These microprocessor based protection relays are programmed software. 

In this project we have used Programmable Logic Controller (PLC) for data manipulation, further more we have programmed more than one protection schemes in single relay namely, Over/under Current, Over/under Voltage and Over/under frequency protection. 

The relay interface designed very user friendly with graphical user interface with help of HMI. The relay settings such as pickup value, delay time and protection type can be selected through touch screen HMI.  

In this project along with PLC as a main component, instrument transformers, contactor circuit breaker, relay modules.

The real time data of relay can be monitor though IoT application using GSM module and IoT controller and can be access through website along with location.

Project Objectives

The objective of this project to design cost effective protection relay with essential qualities of any protection scheme  reliablity, speed and time, sensivity and simplicity. 

Project Implementation Method

PLC (Programmable Logic Controller):  A programmable logic controller (PLC) is used for the comparison of analog step down parameters. Four out of three analog inputs are utilized for current, voltage and frequency. In this project three analog inputs and three digital outputs are utilized.

• Analog Input: Voltage and frequency input is programmed for 0-10 volt signal and current analog input is programmed for 4-20 mA.
• Digital Output: PLC digital output pin 1, 2 and 3 are used for trip, delay and health LED indication respectively. Digital output pin 1 is connected to contactor through 24V D.C relay along with Trip LED.

Current Transformers:  CT scales the large values of current to small value, standardized values that are easy to handle for instruments and protective relays. CT isolates measurement or protection circuits from the high current of the primary system. A current transformer provides a secondary current that is accurately proportional to the current flowing in its primary.

Potential Transformer: Potential transformers are used in electrical power system for stepping down the system voltage to a safe value which can be fed to low ratings meters and relays. Commercially available relays and meters used for protection and metering, are designed for low voltage.  

Current Transducer: Current transmitter converts 0-5A .C current from secondary side of current transformer to PLC standard 4-20 mA D.C current, which is divide into 2000 resolutions in Ladder logic. These resolutions are converted into actual value current in programming through scale function. Current transmitter is operated on 220V have one channel configuration.

Voltage Transducer: Voltage transducer transform step down 0-220 AC volts to 0 - 10 D.C volts. This D.C voltages are scaled from 0 -2000 resolutions in ladder logic. This resolution value is converted into voltage in ladder logic for comparison with help of scale function.

Relay Module: Three channel relay is used for Indication LED operated on 220V. The relays are energized by 24V D.C output from PLC digital output pins when respective condition is meet.

Frequency to Voltage Converter: Frequency to voltage is used for frequency measurement. LM331 is a 8 pin IC which converts frequency from 1-500khz to output voltage 0-10 v pulsating D.C

GSM Module: GSM module SIM900A is used to send  and receive status of medium voltages line through SMS. There are total four GSM modules deployed, in which three modules send data which is status of medium voltage phases to main module. Fourth module is connected with IoT controller that receives status through SMS. Three modules are installed at transformer poles which send status of three phases through SMS.

IoT Controller: The IoT controller NODE MCU 8266 receives data from main GSM module through TX/RX pin to upload to website.

Benefits of the Project

• Commercially applicable 
• Project cab be used in power labs for demonstration to students
• Multi-function protection schemes.
• More than one equipment protection can be achieved by installing more analog input modules.
• IoT based real time data monitoring of relay.
• Simplicity in protection schemes.
• User friendly environment.
• Graphical User Interface.
• IoT based data monitoring through GSM module
• No computer communication needed for setting

Technical Details of Final Deliverable

On completion of this project multi protection function can be achieved. The relay settings can be set as user defined. Measurements page on HMI display current values of parameters, health of relay, type of fault and IoT based data monitoring.

Final Deliverable of the Project

HW/SW integrated system

Type of Industry

Energy  

Technologies

Internet of Things (IoT), Cloud Infrastructure

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com