A power system analysis is a powerful tool for any industrial facility, whether you work at a refinery, pulp and paper mill or about anywhere else that has a complex and/or aging power system. Before you can use a power system analysis at your facility, it would help to know what it is.
What is a Power System Analysis
In March I told you what the minimum power system analysis deliverables are for any project, but I didn't go into detail what a power system analysis is.
A group of studies used to analyze a power systems response to events over different time periods.A power system analysis is a series of studies that reflect the status of the power system at your facility. These analyzes are completed over various time periods, depending on what needs to be studied, however it is best to start with the major static studies including:
- Short Circuit Study
- Protection Coordination
- Incident Energy Study
Getting Started with Static Studies
Most of the time, when work with a power system study they are static studies like we listed above. These types of studies are the best way to get started at your facility, assuming that there are no other issues at the plant that would require transient or short time studies.
Short Circuit Study
The short circuit study was likely last completed when the facility was first put in operation, or if there was a large renovation of the system. If the study is over five years old it is time to re-evaluate and ensure that the equipment ratings, installation, etc are still adequate.Protection Coordination
The protection coordination is another project that is unlikely to be completed after the initial commissioning. Most facilities will have a relay testing program where techs will test and ensure that the relays are operating per the settings, but has the coordination been checked? In a high availabilty facility, like most industrial plants, selective coordination is critical to ensure that only the smallest portion of the system is affected by a fault.
Incident Energy Study (aka Arc Flash Study)
Finally the incident energy study, a major part of an arc flash analysis. Arc Flash hazard warnings are required for the CEC, but like I mentioned before (Arc Flash and Labeling) warning that there is an arc flash hazard present doesn't give you much information. The incident energy study, along with the other information gathered will allow detailed labels for all the equipment in the facility, and is an important input to the facility electrical safety program
Electrical Safety Program
The inputs to the facility electrical safety program, and if there isn't already one, the ability to start one is enough of a reason to get the power system study ready. During the act of getting a power system study prepared, you will be already thinking about how the system is operated, what procedures can be developed to remove the necessity of energized work, and arc flash mitigation techniques can be proposed in areas where energize work can't be avoided. While the power system study is only one part of the over all safety program, it is vital to have accurate information as the results of these studies will be used to determine the level of PPE worn by electrical workers during energized work.Conclusions or follow-up
As outlined above, the most basic power system analysis is a series of studies - short circuit, protection coordination and incident energy - that allows a industrial facility to develop a baseline for other areas of the plant operation, especially the electrical safety program. If you liked what you read here be sure to sign up for our newsletter below, and if you have any questions or comments don't hesitate to contact us.If you like this article and want to hear more sign up for our newsletter at jmkengineering.com/newsletter