Distribution planning is more complex now
- May 15, 2022 5:55 pm GMT
Any electric distribution planning project has gotten more complex. It used to be about getting power to flow one direction to customers, with enough protection to avoid problems, with reasonable reliability.
The loads were mostly known, and no one had to worry about generation on the circuit, simply because it was so small it could not cause reverse power flow or phase imbalance or other issues. None of that is true anymore. A 1000 square meter warehouse that was a 200KW customer can quickly transform into more than 1 MVA growing operation, a home can add 2 electric vehicles (EV) and go from a peak demand of 4 or 5 KW to a peak demand of more than 40 KW. Fossil fuel heating is being transformed into electric both of space heating and water heating. Tankless hot water heaters are dominating the sales of new or replacement hot water systems.
People demand much higher reliability today – in the 1970s an hour outage was not an issue for most people, today a 5-minute outage (momentary under most counting systems) is a huge deal. Resiliency used to be for hospitals and a very few critical locations, now it is desired everywhere.
Planning has become far more complex and has evolved to deal with at least 9 goals:
1) renew the infrastructure
2) increase capacity for EV
3) increase capacity for Solar Photo Voltaic
4) increase capacity for decarbonization (heating, hot water, appliances, etc.)
5) increase resiliency
6) increase observability (including power quality, harmonics, and flicker conditions)
7) reduce outages and outage minutes (reliability)
8) improved segmentation and protection
9) Overall cost of capital and maintenance
Many will argue that PV reduces the load on a circuit, but if one looks 15 minute by 15 minute interval, a funny thing shows up, net zero premises tend to export 3-8 times their average power use, and on a nice spring day it can be 30 times their usage at the time, then they tend to reimport the energy hours to months later to get to net-zero for the year. Even with day/night batteries, net zero premises tend to use as much as a 180% (bi-directionally) energy capacity on the grid then they did when they did not have renewable generation. This is just weather and physics.
Choices for doing this have also gotten more complex to include things like:
1) demand side management
3) energy efficiency
4) looping circuits
5) advanced controls
6) voltage upgrades and/or larger conductor
8) distributed generation
9) protection schemes, and distribution automation equipment
10) communications and control (autonomous, local, or centralized)
11) and more…
Planners now must deal with possibly 100s of scenarios and at least 6 conditions to review in the planning (summer/winter peak day and nights, and spring lowest load day/night). Each run in a single tool can take several minutes to run and more to evaluate. Simple incremental changes to try and optimize may miss the actual best solution. What may look wonderful in one type of analysis may fail in another type of analysis. The typical planning today is done in a static analysis tool.
Not only do static tools need to be used (e.g., CYME, Etc.) but dynamic and transient tools (e.g., PS/CAD, Etc.) to deal with all the issues.
Of course, today there need to be two or more models to do both dynamic and static modeling, static models are far easier to create today. If a single model could be created (and they have very different characteristics so this is not easy), it would reduce people time. Also, automatic fixing of issues within the models would help (elements not being connected, etc.). Anything that can be done to automate model creation, correction and validation will greatly improve productivity. Integration of the models with systems like the Geospatial Information System (GIS), Advance Distribution Management System (ADMS), and other operation technology systems will help. The ability to “pull” Compatible Units (CU’s) into the model to make changes to the model is also a need for a future planning system. Integration of pole loading for overhead work and conduit design for underground (including splice locations and pull tensions) would improve productivity.
Right now, a good planner needs to run hundreds of scenarios to optimize the design. Scripting helps productivity - but better tools are needed to allow the software to optimize based on parameters set by the planner.
I am hoping the usual suspects step up with a new generation of tools. Ideally the planner will be able to turn on and off options and see the results in an easy-to-follow format, showing what happens to each of the 9 (or more) goals.
The industry will struggle to find more planners, so the tools must become far more efficient to allow the planners we have to a chance to keep up with the pace of upgrades and new infrastructure.
Right now a planner has to be fluent in a dozen or more pieces of software (including Excel) to be successful in this transition of the grid, consolidation, automation and improved visualization are the key to being successful in this market.
No discussions yet. Start a discussion below.
Get Published - Build a Following
The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.
If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.