Hybrid AC/DC Secondary Distribution Systems With Enhanced Electric Vehicle Hosting Capacity: A real-world demonstration in Alberta.

The secondary distribution system plays a pivotal role in delivering electric power to residential consumers. Conventionally, secondary distribution systems are implemented using ac configuration. In recent years, the rapid proliferation of loads, such as electric vehicle (EV) chargers has led to significant overloading issues in ac-based secondary distribution systems. A straightforward solution involves upgrading distribution infrastructure including cables and transformers; however, this approach is often costly, requiring substantial investments in both equipment and labor. To address this issue, this article presents a cost-effective alternative: retrofitting existing ac systems into hybrid ac/dc systems using power electronic converters. This hybrid configuration not only enhances the system’s hosting capacity with minimal infrastructure modifications, but also provides additional technical benefits, including improved power quality and smart energy management. A real-world demonstrative hybrid ac/dc secondary distribution system was established in Red Deer, Alberta, Canada, with extensive testing conducted to validate its technical benefits and practical value.