How Nexamp Energy uses ETAP for higher quality and accuracy DC Arc Flash Analysis in BESS

Let’s understand the challenges that engineers face when calculating DC AF incident energy. As we move through our presentation, we will see how ETAP provides solutions to these challenges. The biggest challenge is the lack of accurate methods. For many years, engineers only had the Max power method which could yield overly conservative and even under-conservative results.
Mr. Albert Marroquin, Engineering Division Manager for Dynamics and Electrical Safety Products at ETAP

This case study discusses the modeling of the DC Battery Energy Storage System. These systems are crucial for managing energy supply and demand, especially with renewable energy sources like solar and wind, which can be intermittent. The large grid-scale BESS installations need to be modeled carefully to be efficient but always safe for maintenance. This use case is about a real solution used in the facility in California.

Nexamp Energy is a clean energy company that focuses on the deployment and operation of solar energy assets. The company offers community solar programs, energy storage solutions, and power purchase agreements to provide savings and sustainable energy options for businesses and homeowners. Nexamp primarily serves the renewable energy sector, delivering large-scale solar projects and energy storage systems. It was founded in 2007 and is based in Boston, Massachusetts. Nexamp operates as a subsidiary of Mitsubishi and has offices across the US.

Location: Boston, Massachusetts, USA

Year: 2025

Ensure safe and efficient operation of the existing battery station

Challenges

  • To find accurate electrical calculation methods for existing DC Battery Energy Storage Systems, such as short-circuit, arc flash, and thermal calculation.
  • The different types of batteries connected in the facility should be modeled accordingly with their specific properties, like resistance, inductance and operating voltage level, and battery age.
  • Various conductor configurations have a strong impact on calculations, so they should be considered.
  • Feasibility studies concerned with different scenarios and prediction of events, related to the high incident arc flash energy should be taken.

Which solutions do they choose?

Selected applications

They chose the ETAP software with DC Load Flow, DC Short Circuit, DC Arc Flash, and ETAP Digital Twin as the main solution. 

ETAP ensured compliance with all needed electrical standards for designing and calculating the battery installation.

Why do they use Etap?

Main Customer Benefits

  • Digital modeling of the real battery storage with conductors, busbars, and locations.
  • Easy management of different scenarios, by adding or deleting symbols representing real equipment.
  • Analysis of critical issues like DC short circuit, arc flash, and arc duration using only one workspace.
  • ETAP’s Transient DC AF Solution for Battery Energy Storage System using IEC 61660 helps to estimate more accurate incident energy.

What do they think about ETAP?

Opinions

Let’s understand the challenges that engineers face when calculating DC AF incident energy. As we move through our presentation, we will see how ETAP provides solutions to these challenges. The biggest challenge is the lack of accurate methods. For many years, engineers only had the Max power method which could yield overly conservative and even under-conservative results.
In this simulated [by ETAP software] test, a lithium-ion battery bank was faulted, and the DC Arc current was plotted as a function of time. As we can see here, the rise time constant of a lithium-ion batteries is very short when compared to other battery types such as lead-acid.
Mr. Albert Marroquin, Engineering Division Manager for Dynamics and Electrical Safety Products at ETAP

The type of installation affects the choice of calculation method and hazard level. The various types of battery chemistries used have significantly different short-circuit current behavior. To determine the clearing time results for the Fuse C-areas it's key to is determine key parameters DC Arc Flash calculation methodologies are based on.  
Mr. Terry McKinch, Electrical Safety Manager at Nexamp Energy Inc.



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