Transformer Loading Case Study
Transformer Loading

The Challenge

Transformers are the gateways through which high voltage power passes before it is converted into a lower voltage. They also allow electricity to be delivered safely and reliably into customers’ homes and businesses. Overloading can cause transformers to ‘fail’ and interrupt the flow of electricity. Before power can be restored safely, Alectra Utilities (formerly PowerStream) takes the time necessary to identify the cause and location of the fault.

The Solution

Just as doctors use stethoscopes to listen to the human heart, Alectra Utilities has begun to routinely monitor the performance of the 44,000 transformers on its electricity distribution system, in an effort to identify potential problems before they result in service interruptions.

Each transformer in the Alectra Utilities service territory is connected to approximately eight homes, each of which is fitted with its own smart meter. The smart meters provide real-time information about electricity consumption for each home, and using this information, Alectra Utilities is able to calculate how much electricity is passing through each transformer. Knowing the electrical load on each transformer, coupled with information about each transformer’s capacity, allows Alectra Utilities to predict when a transformer will need to be upgraded or reconfigured. The ultimate goal is to improve customer service by identifying any performance problems associated with transformer loading that could have a negative impact on the reliability of the entire distribution system.

The ability to keep regular tabs on transformers in this way is one of the added benefits of smart meter technology. Alectra Utilities is finding new ways to use the smart meter infrastructure and wireless networks that are already in place — and the information provided by smart meters — to manage outages more efficiently and improve service for customers.

The Benefits

Reliability of the electricity distribution system:

Knowing the loading profiles for transformers in advance can help Alectra Utilities to predict problems before they arise, allowing maintenance crews to be dispatched as they are required.

Safety of the electricity distribution system:

System Control Centre staff are able to view where dangerous or inadequate power level conditions are occurring in real-time and manage them appropriately.

Protecting the system’s distribution assets:

The less wear and tear on Alectra Utilities' distribution assets, the longer their lifespan. Transformer load monitoring allows System Control Centre staff to better manage the system. It also helps to map trends, forecast, plan and conduct forensic analysis of the entire system — all of which will lead to better customer service.

Transformer Loading Case Study (794KB PDF)