Calculations

Computer and engineering calculations can be carried out using software and methods that we have developed and updated over the last 35+ years.

Ground electrode calculations and on-line grounding network calculations.

We are presently revising this process and intend to offer on-line service in a different way. The procedure described in green text below is no longer available, but many of the advantages and disadvantages apply in a similar way:

You prepare the data as a text file, using our instruction manual and send it to us by e-mail. We will do the calculations and return the results to you by e-mail. There are advantages and disadvantages to working this way. The costs of doing analyses this way are more reasonable than buying software to do the calculations.

Advantages and Disadvantages of Using On-Line Software

The use of on-line software was very common in the 80's when complex software was offered on main frame computers that users accessed from a dumb terminal.

As the PC became more powerful, these programs were ported to the PC and the use of the service bureaus disappeared. The software available for PC's also became more sophisticated. It became possible to offer software that could not run on the earlier PC's due to speed, memory and disk capacity limitation.

More complex software with a limited market is more expensive. U.S. $40,000.00 is not uncommon for specialist software.

We believe that some specialized software such as our ground grid, pipeline and grounding network analysis programs, can now be effectively used over the Internet.

Advantages

You do not have to pay high fees for software that may only be used occasionally. You do not have to upgrade each year and pay even more fees. The cost per run is a fraction of the cost of the software.

There is no need to attach a security key to your computer. This is often required when narrow market programs are licensed, to prevent illegal copying.

You avoid having to reload software when there are upgrades and bug fixes or you change your own computer system.

Your computer only needs enough power to do e-mail with a graphics display capability (typically to read and print pdf (public document format) files).

As the computer runs are done with text files, they can be submitted from systems running UNIX, Linux, Microsoft Windows or any other operating system. Specialist software may only be compiled for a few operating platforms.

Disadvantages

There is a delay between submitting the run and receiving the results.

There may be some input data errors that prevent the run from working. In the future, we will provide free front-end software that can be used to scan through the computer models you prepare, so that you can be sure they have no errors before sending them to us.

Ground grids. We can calculate the resistance of ground grids located in soil with non-uniform resistivity. If the grid is large enough that there is a voltage drop across it or it has a reactive component in the impedance, these effects can be modeled by the software. Separate objects, either floating or electrically interconnected by impedances can also be modeled.

Grounding safety from step and touch potential hazards. We can calculate potentials that develop in the soil around a ground grid and from that, the step and touch potentials at the soil surface and can compare these against the tolerable levels as defined by the IEEE. We have developed a rational method for calculating step potentials from soil potential information.

Power system modeling and fault studies. We can model complex single or multiphase power systems and determine the split of current during normal operation and ground faults. This can be used to calculate the ground component of ground fault current for applying to ground grid analyses in determining step and touch potential safety.

We can model very complex power systems using TACLINK. A problem that often arises is how to determine the fraction of ground fault current at a substation that flows into the ground and the fraction that flows in transmission line ground wires that are connected to the substation. Various approximate methods have been developed over the years such as using shielding factors. With TACLINK, the split of current can be calculated properly, allowing for effects like inductive coupling, tower footing resistances.

Pipeline interference effects. We can model and calculate the inductive coupling effects between power lines and pipelines. These effects become more serious each year as utilities seek new rights-of-way for pipelines and are forced to place more pipelines along existing power line rights-of-way. The fault level on power lines is also increasing with system capacity and expansion.

Ground-It.com Consulting Ltd is a wholly owned subsidiary of Pacific Powertech Inc. For a full list of our services, please visit www.pacificpowertech.ca