Page 10 - North American Clean Energy January February 2018 Issue

wind power
Providing for Power Plant BES Safety and Reliability
by Thomas Wilkins and Miles Downing
As an engineer, you’re used to guring things out. If you’re an engineer in the wind power industry, you‘re also used to dealing with the numerous, and sometimes onerous, regulatory changes thrown at you every few months. 2018 brings some challenges to your job, courtesy of the Federal Energy Regulatory Commission (FERC) and the North American Electric Reliability Corporation (NERC). Luckily, we’re here to help.
10
JANUARY•FEBRUARY2018 /// www.nacleanenergy.com
e U.S. Congress wants a safe and reliable Bulk Electric System (BES) with renewables, and FERC and NERC have been providing Orders and Standards to meet those objectives, and there is an upside for renewables; but rst renewables must rise up to “new-challenges” so they can realize the upside with the rest of the BES.
The Challenge
Your mission is to provide for meeting the old and new Point of Interconnection (POI) requirements found in FERC Order 827, NERC standards PRC 024-1-2, and the various other PRC, MOD and VAR standards. Let’s get technical; with regard to the Bulk Electric System – with Rated Voltage greater than or equal to 100KV, and Rated Power greater than or equal to 100MW – it may be achieved with:
• Reactive Following
• High Voltage Ride rough
• Low Voltage Ride rough
• Detailed simulations of the wind power plant
(WPP) or solar power plant (SPP) with PSCADTM
• Including grounding breakers, such as a VDH/
GSMI, at each feeder
FERC Order 827 means that wind generators must
now provide “dynamic” reactive power. New plants can adjust to the new standards, but what about the older wind power plants that were built with this exemption in mind? More importantly, how can you redesign your company’s aging wind plant to meet the newer FERC orders?
More Than Just "Ride Through"
Wind turbines need a system to help them stay online through power interruptions, or “ride through” the event while providing dynamic reactive support during the disturbance. However, “Low voltage
ride through”, “High voltage ride through”, and “ride through with zero voltage capacity” will not, by themselves, provide the functionality to meet the
new FERC orders and NERC standards. WPPs and SPPs are constructed with collection systems; plant components like the main transformer, generator step up transformers, junction boxes, branch, string, and homerun cables, all include an impedance (Z) within the collection system. When it comes to meeting the FERC and NERC standards, overcoming the “Z(s)”
is your problem. “Z(s)” come in many forms, as presented in the equations below:
1. Zelement=[Relement+jXelement] 2. Ielement=Ire+JIim
3. S=PWTG + jQWTG
4. S=VI*
5. VMPT=VPOI + (IMPT* ZMPT )*OLTC*Ratio
6. VHomerun_cble=[IHomerun_cble*ZHomerun_
cble]+VMPT
7. Vbranch=Ibranch *Zbranch+VHomerun_cble 8. Vwtg=Igsu*Zgsu + Vbranch
9. Vwtg_imbalance=Vwtg * Phase_Imbalance Equations 1 through 9 are presented to calculate
the voltages within the collection system of the power plant. ink of them like tree, where you start at the Trunk (5) or Main Plant Transformer (MPT) at the Point of Interconnection (POI), and work your way back to the furthest leaf, or wind turbine or solar generator (9). e idea is to calculate the voltage
Making Logistics Easy
By providing logistics management services through every step of the supply chain, TP&L ensures your shipments arrive at project sites economically, safely, on time and to the quality standards set by the manufacturer. We currently are storing and maintaining 14,769 components in our yards.
Services and Capabilities: • Distribution Services
• Inventory Management • Rail Logistics
• Trucking Logistics
• Indoor/Outdoor Storage • Maintenance
Check out our distribution centers:
Casper, WY | Garden City, KS | Enid, OK | Grand Forks, ND | O’Neill, NE
tpandl.com • 307-262-6748