Smart Monitoring & Protection of Distribution Transformer

As the design of an efficient and reliable thermal protection, system (TPS) for distribution transformers (DT) to eliminate its heating and insulation losses is an important aspect. So our Project presents a low cost solution for the feedback control of thermal protection system for 3-phase distribu

Project Title

Smart Monitoring & Protection of Distribution Transformer

Project Area of Specialization

Internet of Things

Project Summary

As the design of an efficient and reliable thermal protection, system (TPS) for distribution transformers (DT) to eliminate its heating and insulation losses is an important aspect. So our Project presents a low cost solution for the feedback control of thermal protection system for 3-phase distribution transformers using IoT. It has been observed that overloading in transformer results in temperature increase of its winding and expansion of insulating oil. Without any TPS, it leads to the thermal breakdown of oil and melting of copper windings of the transformer, which is the main cause of enormous losses in the distribution system. To overcome these issues, microcontroller base self-intelligent TPS design is contemplated using various feedback control systems. Temperature sensing unit (TSU) in DT oil tank sends a continuous signal to the controller, which interprets this signal to manipulate the function of the cooling system, tripping system and protection failure backup system (PFBS) for DT under excessive overloading. Continuous temperature monitoring and indication is accomplished through liquid crystal display (LCD) and alarm system. In addition to complete automation in TPS, there will be a liability, to sum up with less human involvement, continuous and convenient monitoring with optimized cost. Our Project makes use of state of the art technology i.e., Internet of Things(IoT) to perform online monitoring of almost all the key parameters of Distribution Transformer and protect the DT automatically under abnormal conditions without the need of manpower.

Project Objectives

Through our project, we want to help in making our Grid smart. As we are using IoT so our purpose is to remove the work force that was being utilized for monitoring of key parameters of DT like current, voltage, oil level, oil temperature, humidity, and protect the DT under abnormal conditions. This is achieved by monitoring all the key parameters of DT online and take the actions accordingly in case of abnormal conditions to protect the DT using IoT with the help of IoT based module i.e., NodeMCU ESP8266. We are also making an optimized design for monitoring of key parameters of DT and their protection. Besides as we are incorporating all the key parameters of DT for monitoring and protection unlike the work done previously where people were monitoring and  protecting only few parameters of DT like current, temperature, so we are going for maximum integration through our project. Cost effectiveness is also the aspect we are looking for to achieve through our project.  

Project Implementation Method

Following are some of the key parameters of Distribution transformer we will monitor & protect in case of abnormalities with the help of IoT module i.e., ESP8266-Node MCU:-

• Current

Monitoring

Three current transformers are used to monitor overcurrent of 3-phase Distribution Transformer where each CT will be installed at individual windings of 3-phase transformer. Low current from CTs is then fed to controller setup to measure the actual currents in windings which is then displayed on the LCD.

Protection

Three phase tripping mechanism is used for protection against over current which when senses the current in each phase of transformer, trips the overloaded phase while keeping other two phases intact. Reconnection of phases is also carried out.

• Voltage

Monitoring

Potential transformer of rating 230/12 V is used to monitor voltages at secondary of transformer whose output is first rectified through bridge rectifier & then fed to the filter circuit to remove the ripples.Finally, DC Voltage is fed to the analog ports of the controller for further operation.

Protection

To protect distribution system from voltage fluctuation, unbalancing in 3 phase systems etc., D-STATCOM are used to precisely regulate system voltage, improve voltage profile, reduce voltage harmonics, load compensation and power factor correction. They supply the required stabilizing reactive current either in discrete steps or in variable form.

• Rise/Fall of Oil level

Monitoring

Oil level is monitored using ultrasonic sensor, which provides pulse whose width varies according to the distance between head of oil level. This ultrasonic module measures the distance accurately with a gross error of 3cm & can easily be interfaced with micro controllers.

Protection

The only protection against low & high oil level is to completely shut down the transformer, address the issue & then restart your system. Whenever microcontroller will sense above situation by ultrasonic sensor it will activate the relay to shut down the transformer.

• Oil Temperature

Monitoring

LM-35 whose output voltage is linearly proportional to the Celsius temperature, is used to monitor transformer’s Oil temperature.

Protection

Upon sensing an increase in Oil temperature controller turns ON a fan whose speed is controlled by the controller depending upon the oil temperature. If oil temperature is beyond the safe limits controller will activate the relay to cut off the supply to transformer.

• Ambient temperature

Monitoring

DHT-11 senor is used for monitoring ambient temperature or a thermistor.

Protection

When ambient temperature increases beyond the set limit of HST, the controller turns ON a fan whose speed is controlled by controller depending upon the temperature.

• Humidity

Monitoring

DHT-11 senor is used for measuring humidity. As the humidity changes, the resistance between these electrodes changes, which is measured & processed by IC , & is read by a microcontroller.

Benefits of the Project

• All key operating parameters of distribution transformer including oil temperature, current, voltage, oil level, humidity and vibration are monitored on designed internet of things platform.
• The designed system allows two-way communication between distribution transformer and operator using wireless protocol.
• Data of key parameters of distribution transformer can be stored on online database, which can be utilized for future planning and analysis.
• This system reduces manual operation of distribution transformer under faulty conditions.
• This system also eliminates the usage of conventional methods of protection for distribution transformer.
• Fast operation and accuracy of design system under faults increases reliability and security of protection system.

Technical Details of Final Deliverable

We have made this project as a test bench. This will allow us to apply different disturbances and faults artificially and will allow others to observe how this project responds under these conditions.

Test Bench:

We have divided our test bench into different blocks:

LCD Display: LCD’s are provided to display the real time key parameters of distribution transformer like current, voltage, oil temperature, oil level etc., and notify if any fault or unhealthy condition arises.

Load Block: It consists of load to apply on distribution transformer. Loading can be changed by control knob provided on the main display. This allow to apply overloading and observe the reaction of our protection against overloading.

Fault Block: This block consists of fault module. It applies different three phase faults on transformer which allows user to observe the response of designed system against faults.

Oil Tank: An oil tank is provided to represent conservator tank whose oil level and temperature can be controlled form main display. This allow to check the response of designed system against low or high oil level and against transformer overheating.

Internet of Things(IoT) Platform:

We are using Node MCU ESP8266 for monitoring and controlling of key operating parameters of Distribution Transformer like current, voltage, oil level, oil temperature, humidity. These parameters are monitored online on ThingSpeak whicch is IoT platform and for controlling purposes we bought another IoT platform which is an app called 'Blynk app'. This removes the need of manpower for manual monitoring and controlling of key parameters of Distribution Transformer. 

Final Deliverable of the Project

Hardware System

Type of Industry

Energy

Technologies

Internet of Things (IoT)

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

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