Case Study: Consumers Energy achieves reliable, low-latency protection circuit migration with SEL ICON VSN

Making the Switch How One Utility Is Transitioning Seamlessly From Leased Analog to Ethernet

Consumers Energy, a Michigan-based electric utility, needed to replace 35 leased analog circuits that supported critical protection schemes such as direct transfer trip, permissive overreaching transfer trip, and current differential. Rising lease costs, carrier phaseout of analog services, and strict requirements for deterministic latency, reliability, and compatibility with existing substation equipment made the transition difficult. To address this, they worked with Schweitzer Engineering Laboratories (SEL) and evaluated the SEL ICON multiplexer with virtual synchronous networking (VSN) for leased Ethernet transport.

SEL implemented ICON VSN over leased Ethernet to preserve synchronous, low-latency performance while carrying teleprotection traffic through an Ethernet carrier network. In live trials, the solution delivered contact transfer latency of about 4.5 to 5 ms, with line current differential results showing 2.3 ms round-trip delay, 0.08 ms asymmetry, and no dropped packets during testing. The new leased Ethernet approach provided a cost-effective migration path, improved performance and reliability, and paid for itself in just over two years.

Consumers Energy