NV Energy has a goal of doubling its reliance on renewable energy by 2023. As part of this mission, the utility recently installed the RLSwitcher to switch two 34.5 kV shunt reactors on its transmission system in a substation near Las Vegas.
The shunt reactors, provided by Southern States LLC and located on the transformer tertiary, strengthen the utility’s ability to maintain power quality as it adds to the 50 already completed distributed energy resource (DER) projects. Optimal system efficiency often requires switching these reactors in and out of the system daily. The highly inductive load and the frequent switching is a very difficult duty for traditional switching devices and has led to early circuit switcher failures.
The Tertiary RLSwitcher’s design differs from conventional circuit switchers in that it was designed specifically for switching shunt reactors. The unique interrupter design minimizes the harmful re-ignitions, that cause the failures in general purpose switching devices, allowing the utility to reliably switch the reactors as needed for optimal system efficiency.
“As renewable generation increases, driven by both economic and regulatory factors, utilities face new challenges and opportunities to control system voltage and the power flow from existing and new transmission lines,” says Tom Speas, vice president of marketing for Southern States. “This increasing need for reactive power is leading to new installations and increased switching frequency of shunt reactors.”
NV Energy turned to Southern States after legacy circuit switchers – not intended for high frequency switching of reactive loads – failed. As the utility faces additional switch failures, they’re replacing general purpose equipment with Southern States’ special-purpose switching devices, increasing operation reliability and enhancing grid capabilities.
“People forget that you now have all these distributed energy resources (DERs) integrating into the grid, and you need something to efficiently and safely switch them in and out. That’s where these Southern States switchers play a crucial role,” said Larry Helwig, NV Energy’s senior substation engineer.
NV Energy cited the Southern States Tertiary RLSwitcher and its interrupter design as essential to effectively mitigating potential reignitions and maintaining contact life, providing increased life and reliability.
Southern States’ disconnect switches have been servicing NV Energy for almost three decades. “We went through a phenomenal growth period from the late ‘90s to the mid 2000s and used a lot of Southern States’ disconnect switches. They’ve continually been a reliable supplier of disconnect switches,” Helwig says.