Calculating fault location from COMTRADE file through Wavewin

Introduction: Basic information regarding COMTRADE files (CFG and DAT) was given in earlier post here: Understanding disturbance record files. It is recommended to read this first.

Fault location is and important information, which is provided by fault locator installed for feeders. Normally it is inbuilt feature distance protection. Fault locator has record for latest faults locations (No. of records vary depending on Make/Model of device). Or there may be cases where we have COMTRADE files but access to device records is not available. In these cases we may calculate location from COMTRADE file.

Procedure: 

Open the file with Wavewin software. For fault location calculation, Clicke on Data > Fault Detector, A new window is opened as below

In the DR file, it can be seen that although Secondary is shown on the title bar, current and voltage values are in primary values (Voltage =241646V and Current =219A). This is because CT / VT ratio data is not available in this CFG / DAT file. It is taken as 1:1. It can be checked as below:

The information whether the CT and VT ratio is available or not, is an important information. We have to enter line parameters in Primary or Secondary based on it. In this example Secondary values are equal to Primary values of voltage and current (Due to 1:1 CT and VT ratio). Therefore we will enter primary side line parameters as per relay setting data: 

Positive sequence impedance Z1 = 0.301 ohm/km
Line angle = 80 deg
Zeo sequence compensation factor kZn = 0.750 
kZn angle = -10 deg
Line Length = 100km

In case of actual CT and VT ratio is available in disturbance record files, secondary parameters are to be entered.

Click here for more detail on line parameters

We can specify faulted phase in Advanced settings, which we have not used. Software has automatically sensed faulty phase and shown fault location.