What is Cascading Failure?

For a backup generator to be helpful for your home or business, it needs to provide power almost immediately after your facility loses its primary power source, usually utility-supplied power. This is accomplished by adding your generator into the power grid with an automatic transfer switch. Incorporating instantaneous backup power, whether it’s a single generator or an entire fleet, means creating an interconnected system. When you build this complex system, you also introduce the possibility of a cascading failure.

What is Cascading Failure?

A cascading failure occurs when one part of a complex system fails, therefore triggering the failure of other parts of the system due to an increased load on those other parts. As more parts of the system fail, they continue to cause failure in an increased number of additional pieces throughout the system. This “cascading” increases over time and the root cause is often difficult to pinpoint. While these effects can continue until an entire system fails, the majority of the failures occur extremely quickly.

In standby generators, this phenomenon can be seen when all of the units synchronized in AC parallel fail due to a failure mode on one generator. Cascading failure also describes other interconnected systems, including commercial power grids, financial systems, technical systems (such as data servers), and even personnel networks.

The Causes of Cascading Failure

Widespread cascading failures are triggered by a single event. In the case of standby power, this single event could be one of many. Common triggers include:

• Overloading
• Operator Error
• Natural Disasters (Flooding, landslides, lightning, earthquakes, hurricanes, extreme temperatures, etc.)
• Targeted Attacks

It is difficult to predict a cascading failure due to the large number of possible trigger points and the cascading nature of the problem. Properly sizing and regularly testing equipment to reduce the risk of overloading is possible.