POWER FLOW PROGRAM
The CAI TRANSMISSION 2000® Power Flow program for personal computers combines workstation capabilities with the ease-of-use associated with personal computers. It was developed for personal computers running Microsoft Windows. It is not a converted workstation program. The program offers two solution algorithms for reliable convergence with any power system. This claim has been verified by solving all the publicly available power flow cases submitted to the United States Federal Energy Regulatory Commission (FERC) in response to Form 715 requirements. It contains an interactive data entry and modification feature, and powerful reporting capabilities. In addition, you can customize the program to match your study requirements and hardware configuration. For example, you can redimension the program for different hardware memory configurations and different numbers of buses and branches. Or you can define your own "sets" of buses tailored specifically for your reporting requirements. The TRANSMISSION 2000® Power Flow Program offers the ability to study cases ranging from a few buses to virtually as many as you like without sacrificing capabilities or speed. Whether you work for a utility, industrial organization, or consulting firm, whether you do studies every day or once a year, you'll find the TRANSMISSION 2000® Power Flow Program to be a powerful yet easy-to-use tool.
Solution Techniques
The TRANSMISSION 2000® Power Flow program includes two solution methods—the fast-decoupled method and Newton's method. The decoupled solution method contains an option to use either "XB" or "BX" gain matrices to enhance the program's capability to solve lines with high resistances. The fast-decoupled solution method is usually chosen for large transmission networks. Newton's method may be more effective for low-voltage systems. Of course, both methods can be applied on any size system and both yield exact "ac" solutions. A solution started with one method may be interrupted and restarted with the other. The program will solve split or islanded systems by automatically assigning a reference bus to each isolated portion. Various control features may be activated to:
- constrain var generation within high and low limits;
- automatically control voltages with transformer taps;
- automatically control active and reactive power flow with transformer phase angles or taps, all transformers may have both off-nominal turns ratios and phase angles, and either the tap or phase angle can be varied;
- control area interchange.
Windows Features
Since the program was developed on and for Microsoft Windows, it takes full advantage of the inherent features of Windows. Examples include:
- editing reports on screen including cut, copy, paste, font sizing and print preview
- standard Windows on-line help
- multiple document interface, including nonmodal dialogs that allow you to simultaneously view separate dialogs. For example, you can examine line data while you scroll through bus data and bus reports.
Reports
Among others, the TRANSMISSION 2000® Power Flow program produces summary reports, area interchange reports, bus and branch reports, generation reports, overloaded line reports, fixed-tap transformer reports, variable-tap transformer reports, and voltage violation and regulation reports. The program has a unique "individual bus report" that allows you to scroll through, format, and search the basic power flow results in an extremely efficient and natural way. Reports can be displayed on the screen or sent to a printer. Results can be shown in either MVA or kVA units.
A very powerful part of the program’s reporting capabilities is the "set" feature which allows you to extract buses for study without being restricted to voltage level, area, or zone groupings. Buses can also be selected by more than 16 bus-associated variables using Boolean operators, relational operators, arithmetic operators, and other functions. This feature must be seen to be appreciated. To summarize, all the reports typically available in "workstation power flow" programs are available with to the user far greater flexibility.
Data Editor
The TRANSMISSION 2000® Power Flow program includes an easy-to-use data editor. You can use the editor to build your data base for the first time and to make changes to it. Some of the functions you can accomplish with the editor are:
- add or delete lines, transformers, buses, capacitors, and reactors;
- temporarily outage and restore buses, branches, and shunt devices;
- change impedance values;
- add, modify, or delete load and generation;
- modify generator voltages and capacitor or reactor values;
- modify transformer tap settings and phase angles and transformer controls;
- modify area interchange schedules;
- modify solution parameters.
Many of the changes listed above can also be performed by using special "modify" commands in the program. The changes allowed with the modify commands are "operational" in nature—commands of the same type that a power system operator might execute through supervisory control. These changes are temporary and do not affect the data base. Examples of the allowed changes are load and generation modifications, capacitor switching, transformer tap changes, and the temporary outage of buses and branches. Modify commands can be used to make changes at individual buses or branches, across the entire system, or for a user-defined set of buses. These commands can be put in files to set up extensive batch contingency analysis studies.
Common Format Input and Output
The TRANSMISSION 2000® Power Flow program reads and writes data in an enhanced version of the IEEE Common Format for Exchange of Solved Load Flow Data that is reverse-compatible with the IEEE committee specification. You can also convert data files yourself using the TRANSMISSION 2000® Power Flow Reduction and Data Conversion (PFR) program. This program is supplied free of charge when you purchase the TRANSMISSION 2000® Power Flow program.
Hardware and Performance Specifications
The program is designed to run on Intel-based personal computers under Microsoft Windows. You can redimension the TRANSMISSION 2000® Power Flow program to match your hardware configuration and case requirements. Minimum requirements are an Intel 386 processor with 4 Mb of memory. The case size that you can analyze with the Power Flow program is virtually unlimited (if you want to construct a system with more than 60,000 buses, we would have to adjust the program). The only practical limit to the case size is determined by the amount of memory on your computer.
Graphic Display of Results
The TRANSMISSION 2000® Power Flow program can be used with the TRANSMISSION 2000® One-Line Diagram program to display results on a graphic representation of the system. The One-Line Diagram program is used to create the graphic representation from the existing network data. Existing diagrams can be easily modified to account for network changes.
Pricing Information
The single-copy price of the TRANSMISSION 2000® Power Flow program includes one year of warranty, maintenance, and upgrade service. Multiple-copy discounts, corporate licenses, short- and long-term rentals, and follow-on maintenance contracts are available. If you are currently using another power flow program, you can purchase a copy of Power Flow under our competitive maintenance upgrade program. All you need is a copy of the invoice or a letter on your letterhead naming the competitive program. The program is supplied under an irrevocable, restricted license; copies of the license agreement are available for review. A demonstration package is available and includes a sample copy of the program, instructions, and a User's Reference Manual. Please call us for up-to-date prices.
Training
Training on the operation and use of this program is available at either our location or yours. CAI will also provide consulting services related to the program. For example, you may find it desirable to have CAI personnel help construct your initial data case since this is a one-time investment of labor. Please call us for more information and pricing.
Other Programs in the TRANSMISSION 2000® Series
The TRANSMISSION 2000® Power Flow program is only one of the programs CAI offers for personal computer use. Short Circuit, Protection Analysis, Line Constants, Power Flow Reduction and Data Conversion, Constrained Economic Dispatch, Short Circuit Reduction, Transient Stability, and One-Line Diagram programs are also available.
Ordering and Additional Information
- To place an order or obtain additional information, please contact:
Stephen S. Miller, P.E.
Commonwealth Associates, Inc.
P.O. Box 1124
Jackson, MI 49204-1124
Tel.: (517) 788-3676
Fax: (517) 788-3003
E-mail: Stephen S. Miller