Overview
The Elite Software V-Drop program allows you to quickly and accurately obtain the voltage drop at each node (bus) in a radial electric power distribution system. The voltage drop values are calculated on a "per segment" and "cumulative" basis and then printed as a percentage of the source voltage and as an absolute voltage drop in volts. In addition, the nominal and actual voltages occurring at each point in the network are printed. V-Drop can handle networks containing up to 2,000 components with their associated KVA loads and power factors. The resistance and reactance data for all types of electrical components are stored on disk and are automatically accessed by the program as needed. Specifically, "X" and "R" values are included for copper and aluminum cables, ACSR overhead cables, busway, switches, circuit breakers, and current transformers. Voltage transformers in the one-line diagram may be accounted for as correction devices with no voltage drops, or as simple loaded components. Generators can be entered to correct the voltage at any bus as well. All of the stored "X" and "R" values can be changed by the user to any values desired. Provisions are also made for the input of "special" components whereby the designer can define his own "X" and "R" values for a non-standard device. All data is checked as it is entered and the program is very easy to use and understand. The V-Drop reports not only show computed results, but also reflect all the input data pertaining to those results. V-Drop can work stand alone or in conjunction with the Short and Panel programs.
Program Input
The Voltage Drop program uses full screen editing features that provide a simple "fill in the blank" input procedure. All input data is checked at the time of entry so that no improper data can be entered. If you have a question about what the program is requesting, type a "?" and the program will offer additional explanations about the input data being requested. Upon completion of the input process, all data is saved to disk and can be reviewed and edited whenever desired. Two types of data are requested: general project data and specific electrical component data. The general project data includes the project name, client name, base KVA, initial short circuit KVA available, initial X/R ratio, and voltage at the first node of the system. Specific component data includes the component type (cable, busduct, transformer, etc.), the beginning and ending node numbers for each component, component size, length if applicable, the KVA load on the component if present, and any other information necessary for defining a particular type of component. Input sheets are also provided for the easy organization of your data.
Program Output
The V-Drop program provides two basic types of reports that can be printed either to the screen or the printer. The first report is a nicely formatted presentation of all the input data given for the project. All input data is reflected in this report and the components are listed by type and whether their status is active or inactive. The default X&R component table filenames are also listed. The second report lists the absolute and percent voltage drops for each component segment in the network. These voltage drops are listed on both a "per segment" and "cumulative" basis as a percentage of the source voltage and as an absolute voltage drop in volts. The nominal and actual voltage resulting at the end of each segment is printed as well. In addition, the number of phases (three or single), the "X" and "R" values, the KVA load, and the power factor for that KVA load are listed for each segment. These values are given so that manual verification of the voltage drops can be more easily performed. Shown at the bottom of this page are sample reports for a small project with five buses and four components with loads.
Calculation Method
The V-Drop program uses the percent method of voltage drop calculation as described in the GE Distribution Data Book (GET-1008H). This method makes it easy to account for voltage transformers, single and three phase systems, and frequencies of 50 or 60 hertz. V-Drop is supplied with built-in "X" and "R" values for the various electrical components. These values were taken from several sources including the Bussmann's manual called "A Simple Approach to Short Circuit Calculations", the Federal Electric Pacific Catalog, and the GE Industrial Power Systems Data Book. However, these values can be easily revised to anything you want. Besides revising existing values, the V-Drop program also allows you to create additional "X" and "R" files so that many different types of data can be referenced. The program calculation method is detailed in the user's manual so that exact manual verification can be easily performed to check the program results. The comprehensive user's manual also includes tutorial information concerning the use of the program and general voltage drop considerations in system design.
System Requirements
Elite's DOS software application V-Drop is compatible with all Windows operating systems (Windows 95, 98, ME, NT 4.0, 2000, and XP). The minimum hardware requirements to run our application are the same as the minimum hardware requirements to run the operating system that the application is installed on. Additionally, 1 MB of hard disk space is required to install and run V-Drop.