The demand for an incessant, reliable and quality power supply is increasing. However, with more and more integration of renewables, EVs, electronic device usage and, increasing demand, the stress on the grid is also increasing. This has brought a growing awareness for the deployment of monitoring and protection devices in the network. Despite this distribution transformer (DT), which is one of the most important part of the distribution network, is often ignored. The reason is that transformer being a static device and having an average life of over 20 years, is often forgotten. Further, most of these DTs are installed in remote locations and monitoring them is a challenge. The present system of monitoring is riddled with its own problem. They are all time-based manually monitored without any transparency and involve a lot of human intervention which leads to errors and immediate action cannot be taken. Also, the current practice monitors only the basic electrical factors and ignore the more important physical parameters. For an asset as important as a distribution transformer, clearly, this is a primitive and inefficient way.
Why IoT based remote monitoring?
Around 15-18% of distribution transformers fail every year in India. This is huge when compared to the failure rate of just 2-3% in developed countries. The major reasons for transformer failures are insulation failure, moisture ingress, oil contamination, overloading and manufacturing defects.
Most of these failures can be avoided if we do proactive maintenance and monitoring. However, the current practice of manual monitoring has its own share of problems. First of all, we need to have maintenance staff to consistently monitor the assets. Secondly, it may not be possible for him to monitor all the parameters manually. Further, because of human intervention, there is an inherent inaccuracy in the data being taken. Also, the transparency of data is not guaranteed. And most importantly, since this is not real-time continuous monitoring, one may not be able to take immediate corrective action once a parameter breaches the prescribed limit. All this calls for automated real-time monitoring where the human intervention is minimal and data can be continuously collected and stored.
Now, with the recent advancement in IoT based systems, cloud infrastructure and readily available sensors, all these challenges can be addressed economically by an IoT based remote monitoring platform.
Some contrasting benefits of IoT based monitoring compared to present
|Type 2||Type 3||Type 4|
|Traditional Monitoring||Smart meter based monitoring||SCADA monitoring||
|Time-based (half-yearly, annual etc.)||Time-based. Electrical parameters monitored in addition to case 1||Real-time. SCADA is hardware-oriented with complex architecture & vendor-specific protocols||Real-time. IoT is software oriented with simple architecture.|
|Manual (user inspects & collects data)||Same as type 1. Scope for real-time monitoring in future||Automatic monitoring from a dedicated remote location & access to limited users||Automatic monitoring with access to multiple users & from any location|
|Written & documented||Written & documented||Digital||Digital|
Asset Condition Transparency
|Nil||Low (only load & electrical parameters)||Good (But monitoring by limited users only)||Better than all types. No limit on no. of users to monitor|
Cost Vs Failure
|Nil – Very High||Low – High||High – Moderate||Low – Low|
|NA||NA||Difficult & Costly||Easy & Cheap|
SCADA ecosystem consists of numerous vendor-specific protocols, which are mutually incompatible. Also, the cost & process of scaling for IoT is better than SCADA. These factors form a significant challenge for organizations that need a system-wide view of operations such as electric utilities working towards a smart grid.
What makes IoT monitoring more versatile is its ability of data aggregation which further provides
a. Predictive Analysis (Forecasting)
b. Prescriptive Analysis (when, why, what to do)
The DTMS monitors the vital parameters of a transformer (Electrical & Physical) in real-time by deploying sensors on the Transformer. The collected parameters (e.g. oil level, oil temperature, winding temperature, currents, voltage, humidity etc.) are sent to an IoT gateway that houses all the electronic circuitry to gather and digitize the data and sends it to the cloud via internet following the standard protocols( HTTPS/MQTT etc.). The application is hosted on the server and is available to the user in the form for a dashboard that shows all the parameters in real-time and may also include various analytics feature. The solution diagnoses & sends alerts/notifications via SMS & email whenever there is any abnormality sensed. One can monitor the transformer remotely from anywhere on mobile or desktop. This allows maintenance to be scheduled and corrective action to be taken before the failure actually happens.
Benefits of IoT based monitoring solution
- Some of the benefits that IoT based DTMS provides are:
- Reduction in preventive maintenance cost by approx. 30% by condition-based maintenance
- Increased average uptime thereby increasing customer satisfaction
- Optimum asset utilization (over/under load utilized asset)
- Increased revenue by reduction in failure rates ( * a 5 % reduction will save roughly over 50 crores of revenue)
- Reduction in average outage duration (a 24-hour reduction in downtime will reduce the revenue loss by 30%)
- Monitoring of power quality parameters like THD, pf, voltage variations etc.
- Increased revenue by reduction in theft by real-time remote monitoring of energy meters (AT&C losses can be bought down to 7-8%) by proper identification of theft which is possible through IoT based monitoring of meters
- Real-time alerts on phone in case any critical parameter breaches threshold
- Predictive transformer health parameters higher uptime of transformer
- Downtime analysis and calculation of revenue lost
- Asset register along with repository of data in the cloud, geotagged assets on a single dashboard
- Better management of field service & maintenance
*Note: This is a generalised estimation based on the total failures & related revenue loss across the country. However, these may vary from utility to utility depending on the average rating, failure rate, type of failures & time required to replace the faulty transformers.
Condition-based remote monitoring (CBM) is the need of the hour where equipment condition will be known remotely and maintenance schedule, as well as control, can be achieved in real-time. IoT based monitoring solution provides an easy and inexpensive option to switch to CBM and take care of one of the most important assets of the power system. A healthy distribution transformer is an irrefutable necessity for a healthy power system. It’s high time we come out of the primitive way in which we maintain this vital asset.