Page 11 - North American Clean Energy January February 2018 Issue

with the collection system for a given POI voltage (with a Real and Reactive power ow through the POI). e standards include dynamic conditions, so we need to include control systems and other dynamic elements into our considerations, where many calculations are needed to provide a more complete picture. To gain better insight into the plant, we need a time domain analysis tool like PSCAD.
Why PSCAD?
PSCAD uses time domain/time step simulation in the microsecond range (with combined Power System Simulations, the control system, and control logic) to
provide engineers an animation of the performance of the WPP or SPP. is lets the engineer “see” an ideal of the dynamic constraints that appear during a disturbance,
or contingencies on the power system. With the Control System coupled to the electric power system, PSCAD can use reduced order models to simulate constraints within the plant; this makes it easier to determine the type of ride through and dynamic power controls needed to meet relevant FERC and NERC targets.
Constraints
e constraints measured in PSCAD are dynamic and transient – they appear and disappear. Within the plant, constraints may be physical and/
or regulatory, and are generally measured in di erent locations, cataloged, and checked against operating requirements as dictated by FERC and
NERC. At the end of the day, however, constraints are compared against the interconnection agreement. A technique called Reactive Following, used
to assess the constraints, provides plant owners several safe and reliable methods to exceed their Large Generation Connection Agreement (LGIA) compliance, with both the Transmission Provider (TP) and electric reliability organization (ERO). Your interconnection agreement requires a certain amount of reactive power support to the transmission system. Reactive Following will help your facility meet FERC Order 827, NERC PRC-024,
and any other requirements for non-synchronous generators. It’s all very technical, and can be confusing even for a seasoned engineer, but with the right tools, you can nd the optimized solution for your company.
Miles Downing and omas Wilkins are both independent Power Systems Engineers who, for the past 19 years, have worked in the power systems industry with a focus on renewables. Miles Downing is a registered professional engineer with a Master Degree from Portland State University
in Power Systems Engineering. He has worked with Bonneville Power Administration and with EDF Renewable Energy, and is currently based out of Vancouver, Washington. omas Wilkins has a BSEE from San Diego State University and is an inventor with several power systems related patents, and has worked both nationally and internationally on interconnection related matters for renewables. He is based out of Henderson, Nevada. Miles and Tom maintain a website called Rfwind.com
RF Wind | www.rfwind.com
North American Clean Energy
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