Wednesday, June 19, 2013

Utilities and system protection

Protective relaying work directly impacts system reliability.  In fact, you could say that it's the insurance policy for protecting the assets of a utility.  That’s why it’s vitally important that the consultant a utilities hires possesses the necessary expertise and judgment to make the right call, and can easily adopt the preferred standards and protection practices used at that utility.  Protective relaying is not something learned in a standard electrical engineering curriculum.  It takes years of practice to become competent. 
Charles Mason aptly described protective relaying as both an art and science.  That’s because there is not a singular, scientifically-proven “best approach” to setting relays.  In fact, there occasionally are circumstances in which perfect coordination and protection simply cannot be achieved and the engineer is required to make a judgment call.  (Fortunately for our clients, Commonwealth's roots in the industry date back to 1888 and we have engineers with over 40 years in the business, so we bring a wealth of knowledge to client projects and have a proven track record of making the right call.) 
Modern digital relays are complex.  Each client will have unique features used, philosophy, settings criteria, and relay set up.  This “tribal knowledge,” developed over the years, may not even be known to all internal engineers.  We are helping clients to capture and document this knowledge, and providing a more rigorous, standardized format for presenting study results.  We also help translate this knowledge into standards that enable consistent relay setting by utility employees or consultants.
There are two major protection software programs in the electric utility transmission system arena – CAPE and ASPEN OneLinerTM.  With nearly a 2-to-1 utility market share, ASPEN is considered quite user-friendly. CAPE is more robust in modeling capability and running system simulations, but requires a steep learning curve and is more difficult to learn compared with ASPEN.  Commonwealth is one of a very few consultants highly experienced with both.  
Here are the Top 10 reasons to connect with Commonwealth for system protection services:
1)     We can be a seamless extension of your staff, following your utility’s philosophy and settings criteria.

2)     You get the benefit of our extensive experience with CAPE & ASPEN.

3)     You can trust us to review your settings or utility practices for NERC compliance.

4)     We can perform your system wide upgrades, including design work, updating protection standards, and relay studies and analysis to provide the relay settings.

5)     You can address the increasingly important arc flash issues by using the automated process we developed in CAPE to efficiently perform calculations in the utility environment.

6)     You can tap into our experience with analyzing event files from digital relays for troubleshooting or independent review of relay settings to diagnose misoperations.

7)     We can provide databases and data management to build combined short circuit models using data from both CAPE and ASPEN users.

8)     We have extensive field experience with commissioning and testing of new relaying systems.

9)     We can provide protection studies, coordination, arc flash, and troubleshooting for power plant electrical systems.

10)  We can help you with overflow work or get you through a period of new staff development.


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