By Arnau Sans | October 2021

 

"A major electrical developer for the yacht industry asked us to perform arc flash studies on their newest ship. However, the on-board electrical installation was a hybrid of AC and DC power supplies. Out of 30 distribution boards, eight were designed for a DC system, with batteries and rectifiers."

Standards for arc flash studies are based on AC power supplies. Arc flash studies for AC power electrical systems are well documented, but DC networks require a different approach... The challenges associated with performing arc flash studies on a DC network, along with the additional complexity of performing arc flash studies on a ship/yacht, made this an interesting project!

We hadn’t carried out DC arc flash measurements before. However, tackling a new idea is always challenging and therefore interesting. We realized there was a marked difference between what we had been doing before, and what we had to do in this case. That meant doing research, discovering   possibilities, finding out what’s possible with current tools, and developing new tools using Python/Excel. Very exciting!

Some technical aspects of the ship’s design were new to us, making this very different to our previous experiences. For example, several small sets of batteries had no protection device connected. Below a certain size, Lloyds doesn’t regard batteries hazard in terms of short circuit or Arc Flash.

A key technical challenge was researching and identifying how DC arc flash simulations work. The project allowed me to learn how to design DC networks in power system analysis software. In addition, we developed better understanding of how to tackle customer issues and streamline interaction between the customer and engineer for greater efficiency.  Research, knowledge and a deep interest in finding the best solution for our customers helped our engineers deep dive into transforming a challenge into a solution.

By providing a complete overview of the electrical installation, we were able to identify possibly unsafe locations with the customer and discuss possible solutions to improve the arc flash safety at these locations. HyTEPS Power Competence Center engineers help the customer improve their protection system and prevent possible catastrophic situations at sea! In addition, the customer can market itself as a company that ensures a strong safety standard for customers.