GENERAL INFORMATIONS

HOW TO MAKE THE TEST

CONNECTIONS OF THE RELAY

Z_EVOLV: The program

Installation

Running the program

DEFINE SETTING

EXECUTE THE TEST

Test results

GENERAL INFORMATIONS

The program Z-EVOLV.PRG has been developed using the module EDITOR of the software XTEST. This manual describes the revision 1.0.

It allows to perform evolving faults on a distance relay. The purpose is to check the reliability of the relay during a fast changing fault.

With this program the user can define a sequence of two different types of faults. For each of them it is possible to define:

The type of the fault:

Single phase

Phase to phase

Phase to phase and ground

Three phase

The phase under test: Rn, Yn, Bn, RY, YB, BR, RYn, YBn, BRn, RYB.

The fault impedance in module and phase

The direction of the fault: Forward or Reverse

The duration of the fault

This allows, for instance to perform the following test:

Phase to Phase fault RY, at 0.45 W, 35, Reverse, for 0.056 seconds, followed by

Phase to Phase and ground fault RYn, at 0.35 W, 45, Reverse, for 0.3 seconds.

Sometimes relays trip instantaneously after such a fault in reverse direction.

HOW TO MAKE THE TEST

The operators must first connect the relay under test. Run the program

The program requires some parameters:

Source impedance: module, phase angle and earth factor

Earth factor for the line forward

CT side: line or busbar

Type of fault calculation with Source impedance model or Constant current.

Test data

CONNECTIONS OF THE RELAY

T           Connect voltage and current outputs of the test set to the distance relay, as usual.

T           Connect the general trip of the distance relay to digital input C1 of the test set as Normally Open. In case there is no general trip you can put the three single phase trip commands in parallel.

T           Supply the relay from the test set (unless it is energised by a local supply).

Z_EVOLV: The program

Installation

To install the program, insert the diskette in the A: drive.

From DOS or from Program Manager of Windows type A:INSTALL.

The automatic procedure will install all files into the correct directories, together with other distance relay test programs.

Running the program

To run the program, start the module RUN of the software XTEST.

Then select File - Open from the menu, or click on of tool-bar.

Select the directory C:XTESTPRG

Select Z_EVOLV.PRG and then press OK to confirm.

The program starts and the following screen will appear.

At the bottom are indicated the all used by the program during the execution.

Start the program by pressing the icon

The following window will open-up (better to expand at full screen).

It is a menu where the user must decide whether to define all settings for the test or go straight away to the test itself.

In case the user select to define the setting, a series of input windows will be presented

DEFINE SETTING

The first window requires that the user defines all test datas:

The meaning of the input fields is obvious. Press OK to continue.

In the second windows well have to define:

The meaning of these parameters is also well known. Any way test parameters are summarised in the following table.

After this, pressing the button OK, the following window is presented:

The user must decide if the model to be used is with source impedance. If yes, then all source parameters must be defined:

otherwise the test will be performed at constant current and the unnecessary parameters wont be displayed.

EXECUTE THE TEST

When executing the test, as already said, we have to define fault parameters for cycle 1 and 2.

The first window requires that the user defines type of fault for the first cicle:

Once the type of fault is selected, the user is asked to define the following parameters:

which are:

Phase under test according to the type of fault

The fault impedance (module and phase)

Duration of the first fault

Direction of the fault : forward or backward

The same the user must do for the second cycle, after which the defined sequence will be executed and the result presented in the input window and stored in the result one.

Test results

A table form result is opened at the end of the test. The first part of the table is the summary of all selections made for the test.

The second part includes test number, fault type, fault impedance (module and phase), fault direction and trip time.

This example shows a typical error: an evolving fault in back direction is cleared instantaneously as soon as the fault changes from Phase to Phase to Phase to Phase and Ground.