Hobby website I use to simplify my life
- Dobble
- CSV Plotter
- Distance Protection Fault Plotter
- Earthing Calculation Tools
- Earthing Surveys
- Electrical Engineering Tools
- EMC Calculations
- Railway Faults
- Railway Voltages
Note.
If a page is not working for you, it's probably because an update has broken your cached version.
To fix this, refresh the cache by pressing Ctr+Shift+R.
This game can be played by one or two players. You can only get a high score in one player mode. Try to find a matching symbol between the reference and player card. Every card has one match. Click on the match to gain a point and receive a new card. If you click on the wrong match, one point will be deducted. This is to avoid cheating by spamming click. The math used to create this game can be found here.
There are two modes, "Process Upload" and "CSV Formatted". The default mode is to process the upload. This converts all the csv information
into an array. All text is removed from the array. If empty spaces are needed, make sure to write "null" in the csv. Everything other than numbers
is removed when processing the data. Rolling averages can be used by entering a number in the input box that appears while hovering.
The Start date option can be used to create an x axis with custom dates. The rate can be chosen to match the
original dates in the csv. The original dates usually don't survive the processing, due to so many different formats existing for dates.
The enable equations options is used for data manipulation. Every column of data is represented by a letter. The default shows just the letters, "a", "b", "c", etc.
Equations can be applied to individual columns. For example "a*b" will multiply the first two columns. Any form of javascript math can be applied to
the columns. For more information about javascript equations see here.
When using "CSV Formatted":
For the csv file to load correctly, delete all unneeded rows and columns. The first row can be left to be used as labels. The other rows
have to only contain numbers to work. All columns must be the same width.
Using Easergy / S1 Agile, open the disturbance record data. Go to "Files" > "Save As" > "CSV Format" > "Vector Values (RMS & Ang)".
For the csv file to load correctly, delete all unneeded rows and columns containing letters. The uploaded csv file must only contain
four columns of data with no labels. The first column must contain the "Vcat-RMS" data, the second column the "Vcat-Ang",
the third column the "Icat-RMS" data, and the fourth column the "Icat-Ang".
To plot secondary values to primary values, select the secondary radio button and input the VT and CT ratios in the advanced section.
Some relay disturbance record display and export the records using secondary values. If this is the case, select the secondary DR
radio button. The fault sample time can be used to calculate in what zone the relay tripped. The default sample time is of 1 ms, but
other sample times are also used. The sample time can be found in the disturbance record data.
The calculations used for this page have been extracted from Engineering Recommendation EREC S34 and Technical Specification 41-24.
This page can be used to document the results of Soil Resistivity and Fall of Potential surveys. Enter the test location to save
the results with the specified site name.
Soil Resistivity
Enter the soil resistance values and check that the soil resistivity values are consistent.
Soil resistivity can be tested using the Wenner test as described in section 10.2.2 of BS 7430 and below.
Drive four equally spaced test electrodes to a depth of not greater 5% of their spacing apart.
Pass current between the two outer electrodes. Measure the earth potential between the two inner electrodes.
The resistance R should be taken as the ratio of the voltage between the inner electrodes and the current between the outer electrodes.
In homogenous soil the average resistivity ρ in ohm metres (Ωm) may be taken as: ρ = 2π a R.
Where:
a is the spacing between electrodes, in metres (m)
R is the resistance measured between the middle electrodes, in ohms (Ω)
See the figure below to get a better idea.
Fall of Potential
The outer test electrode, or current test stake, is driven into the ground 30 to 50 metres away from the earth system,
and the inner electrode, or voltage test stake, is then driven into the ground mid-way between the earth electrode and the current
test stake, and in a direct line between them.
The Fall of Potential method can be adapted slightly for use with medium sized earthing systems. This adaptation is often referred to as the 62% Method,
as it involves positioning the inner test stake at 62% of the earth electrode-to-outer stake separation. When using this method, it is also advisable to
repeat the measurements with the inner test stake moved ±10% of the earth electrode-inner test stake separation distance. If these two additional
measurements are in agreement with the original measurement, within the required level of accuracy, then the test stakes have been correctly positioned
and the DC resistance figure can be obtained by averaging the three results. There is a label which shows if the results of the 62% test are valid or not.
See the figure below to get a better idea.
The electric fields get mostly blocked out by solid and conductive objects. The links below contain the references for the equations and very useful information about electric and magnetic fields.
- ENA Facts
- Very informative on low frequency fields
- EMF from electric trains
- Limits stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP)
- Railway capacitance p.39
- Electric field equation p. 7
- Electric field equation alternative reference
- Magnetic field equation
- Magnetic field equation alternative reference
- Effect of finite length on magnetic field calculations
- Information about calculations
The railway faults page was put together using a bunch of made of equations and basic electrical engineering principles. The following variables were used for the calculations:
| Variable | Description |
|---|---|
| IF | Fault Current |
| IS | Source Fault Current |
| KRR | 1 for single rail return, 2 for DRR |
| KT | Number of tracks minus 1 (If one track, this is set to infinite) |
| LBT | Distance Between BTs |
| LC | Current Location |
| LS | Distance between substations |
| LXB | Cross Bonding Distance (if LXB = 0 or LXB > LS then LXB is set to LS) |
| LXBP | Distance since last Cross Bond |
| VS | System Voltage |
| ZAEW | AEW Impedance |
| ZATF | ATF Impedance |
| ZBT | BT Impedance |
| ZCAT | Catenary Impedance |
| ZCW | Contact Wire Impedance |
| ZDEP | Departing Impedance |
| ZF | Fault Impedance |
| ZOLE | ZCAT // ZCW |
| ZR | Rail Impedance |
| ZRET | Return Impedance |
| ZRSC | RSC Impedance |
| ZS | Source Impedance |
| ZT | Telecoms Impedance |
Source Impedance:
OLE Impedance:
Depart Impedance (OLE impedance to fault):
The current location (LC) is reset to 0 at each substation. The distance between the substation (LS) changes after each substation. The impedance once
the current location (LC) reaches the substation distance (LS) is added to the impedance of the next calculated section.
Return Impedance:
The distance since last cross bond (LXBP) is reset to 0 at each cross bond. The impedance once the distance since last cross bond (LXBP)
reaches the cross bond distance (LXBP) is added to the impedance of the next calculated section.
Fault Impedance:
Fault Current:
Like the railway faults tab, this was also put together using a bunch of made of equations and basic electrical engineering principles.
The calculations are a continuation of the equations in the previous section. The fault current from the previous equation is used to calculate
the railway voltages. To get the voltage of the rail, the calculated current is multiplied by the return impedance. This return impedance has
to take the return impedance via earth into account. This impedance path is via the rail leakage to earth, as well as the mast connections.
The following variables were needed, in addition to the previous variables in the above section.
| Variable | Description |
|---|---|
| LM | Distance between OLE masts |
| VR | Rail Voltage |
| ZER | Earth Return Impedance |
| ZM | Mast Impedance |
| ZMT | Mast Impedance Paralleled |
I've currently attempted to calculate the rail voltages three different ways. The calculations for these attempts are below.
Rail Voltage (without the masts):
Rail Voltage with the masts in series:
Where if LC is divisible by LM without a remainder:
Note. ZMT starts of as an infinite number, reducing each time it is parallelled.
The last approach is probably the closest to being correct. The return impedance calculation from the previous section has a slight modification.
The mast impedance ZMT is parallalled with the AEW impedance ZAEW.
The rail voltage then uses the same equation as the first one, using the updated ZRET value.
