html{display:none} Distribution Automation Controller (DAC) Helps AEP Advance Customer Service | Schweitzer Engineering Laboratories

Distribution Automation Controller (DAC) Helps AEP Advance Customer Service



AEP Ohio, a subsidiary of American Electric Power, serves 1.5 million people across 88 counties. In response to the rapidly changing energy landscape, the utility was looking to leverage new technology to improve efficiency, identify and respond to outages more quickly, and better monitor and control operation of the distribution system.

Customer Profile

  • Customer: AEP Ohio
  • Location: Columbus, Ohio
  • Industry: Utility
  • Application: Distribution Automation

Since the radio system and the Schweitzer [SEL] system both use industry-standard protocols, the integration was very simple… We plugged everything in and it just started communicating.

Paul Zawada
Principal Engineer, AEP Ohio


To improve their service, AEP Ohio planned to initiate a smart grid automation project, including deploying distribution automation across 70 circuits. This automation would give them greater distribution system visibility and improve service for more than 100,000 customers.

AEP Ohio installed approximately 300 new reclosers and paired them with SEL-651R Advanced Recloser Controls. The automation project also included the following equipment:

  • SEL-2401 Satellite-Synchronized Clocks
  • SEL-2890 Ethernet Transceivers
  • An SEL-3555 Real-Time Automation Controller (RTAC) serving as a DAC
  • Third-party radios

The radios send data from the reclosers to the DAC. GPS clocks synchronize the recloser’s time with substation devices and provide time stamps so engineers can precisely analyze an event from multiple devices. Ethernet transceivers in each recloser control cabinet provide technicians the access to download recloser event data remotely.

But the key to the system is the DAC. The DAC responds to events on the distribution circuit, recognizing fault conditions from the circuit breaker to any recloser on the line. When a fault occurs, the DAC waits for the circuit breaker or recloser to progress through its reclosing sequence. It then commands downstream devices to isolate the faulted line section and backfeed nonfaulted line sections from the source with the most available capacity. In addition, the DAC responds to open-phase conditions, performs load shedding, and flags and fixes miscoordinations.



AEP Ohio’s power system can now automatically respond to a fault, isolate the issue, and keep the lights on for more customers after an event. The SEL DAC builds on AEP Ohio’s local protection technology so that they can isolate open-phase conditions. The new system also allows engineers to remotely program the reclosers and retrieve events, saving AEP Ohio money by not having to send crews out to the individual devices. AEP Ohio can identify problems faster, which means they can restore power faster to their customers.

Additionally, AEP Ohio customers experience enhanced power reliability. Line sections that could have been affected by an upstream fault can now be backfed, after the faulted section has been isolated, to seamlessly restore power to more customers than ever before.

We can get equipment repaired before there’s actually a customer complaint.

Paul Thomas
Grid Management, Deployment Supervisor, AEP Ohio

Request a Follow-Up


Request a Follow-Up

Innovation, Persistence, and a New Beginning

View The Project
Innovation, Persistence, and a New Beginning