Knowledge Base

Coordinated Initialization of the Load Distribution Equivalent, Load Characteristic, and Load Distributed Generation Models

Generator modeling in transient stability simulation software has been modularized for decades. Generators are modeled using a Machine Model, Exciter, Governor, Stabilizer, etc.  Several new modules for generators have been added in the past few years specifically for wind turbine and renewable energy modeling. Load models however had remained stuck with only 2 models: a load […]

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January 8, 2016

Voltage Compensation Data Input Errors leading to Transient Instability

Voltage Compensation can be modeled in a few different ways in PowerWorld Simulator.  First, there are Rcomp and Xcomp values which can be specified with the various synchronous machine models such as GENROU, GENSAL, GENTPF, and GENTPJ.  In addition, you can add specific other generator models to represent compensation: COMP, CCOMP, COMPCC, CCOMP4, and IEEEVC. Without […]

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October 22, 2015

Using Contingency Categories for monitoring of different voltage deviation limits for different contingencies

Previous knowledge base articles have covered both Monitoring voltages for Post Contingency Voltage Drop Criteria Monitoring which covered how to monitor all buses in the system for a particular voltage drop. How to specify different Voltage Deviation Limits for different buses in Contingency Analysis which did a similar thing but allowed the criteria to be […]

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September 30, 2015

GIC and Geographic Data View

Simulator’s Geographic Data View feature is uniquely suited for visualizing geomagnetically induced current (GIC) flows over a wide area. In the graphic below, each substation is depicted by a colored circle. The size of the circle is proportional to the GIC flowing through the neutral, while the color indicated whether GIC is flowing into or […]

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August 18, 2015

WECC RAS and Contingency Workshop Materials

PowerWorld Corporation staff led a RAS Modeling Workshop at WECC offices on May 27 – 29, 2015 in Salt Lake City.  This workshop consisted generally of the following material. 3 hours of pure presentations 4 hours of basic software training on PowerWorld Simulator 7 hours of hands-on workshop with engineers from throughout WECC sitting down to model […]

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June 2, 2015

GIC and Substation Coordinates for Line Taps

To properly perform geomagnetic induced current (GIC) analysis, substation geographic coordinates (longitude, latitude) must be provided for all substations that contain terminals of transmission lines for which a GIC-induced equivalent DC voltage is applied. Generally this includes all lines greater than the minimum length and minimum voltage specified on the GIC Analysis Form. The need for coordinates […]

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March 26, 2015

Assigning Costs to Control Adjustments in OPF

Download the example files. Simulator’s Optimal Power Flow (OPF) has 2 options for objective functions: Minimum Cost or Minimum Control Change. Generally Minimum Cost is used where generator bids or costs and load benefits are known. Minimum Control Change is used where it is desirable to relieve transmission overloads with minimum deviation from the present […]

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March 2, 2015

Transformer GIC Thermal Response

This spreadsheet (revised November 3, 2017) includes sample formulas for calculating transformer winding and metallic parts hot spot temperatures as described in the NERC white papers Transformer Thermal Impact Assessment White Paper and Screening Criterion for Transformer Thermal Impact Assessment. It is provided with the following disclaimers: Input parameters in this spreadsheet are samples provided for illustration […]

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February 9, 2015