Test example: Areva 632 differential relay

Purpose of the test:

1. Check Ir/Id characteristica. Pick-up currentb. Gradient of points on slop 1c. Gradient of points on slop 2d. Instant tripping current

2. Check harmonic restraint a. 2nd harmonic restraintb. 5th harmonic restraint

3. Check trip time

Select ‘Differential’module

Setting and test windows

Installation and connection

Tripping characteristic

Equation for Ir/Id tripping characteristic

Characteristic equation for

Characteristic equation for slop 1

Tripping characteristic (continued)

Characteristic equation for slop 2

Rapid tripping current

Settings in AREVA 632

In the Relay setting paper or In AREVA632 we can find the following settings. Those marked yellow will be filled in the test module accordingly for proper test.

Power of the transformer

Vector group for A-B

Vector group for A-C

Pick-up current (pu value)

Rapid tripping current (pu value)

Gradient of slop 1

Gradient of slop 2

Knee point of slop 2 (put value)

5th harmonic restraint

2nd harmonic restraint

Matching fact. Kam, a

Matching fact. Kam, b

Matching fact. Kam, c

Matching factor for side A

Matching factor for side B

Matching factor for side C

0.7-5

0.7-5

0.7-5

Set ‘Setting’ in software test module

Click ‘Setting’to open the following screen and fill in the settings according to AREVA632 relay settings.

‘setting’screen in Differential test module of

PowerTest

There are two knee pointsfor Areva 632

Knee point 1 Knee point 2

Set ‘Parameters’in software test module

Click ‘para.’to open the following screen and fill in the settings according to AREVA632 relay settings and test requirement.

‘para’screen in Differential test module of

PowerTest

After we complete the setting the principle Ir/Id curve will be displayed on the screen

Set test items

By default the Differential (6I) module contains the following test items.

Activate the test items in the list

Click it to activate or deactivate this test item

Test item is activated

Test item is deactivated

1. Pickup test

Name: user definedTest Phase: defined in ‘para’IR: Ip1 here indicates the pickup current setting. We can select 0‐1*Ip1Type: the quantity selected here will be used in the test report. Because we are testing pickup current we need to select Id>

2. Slop test

Name: user definedTest Phase: defined in ‘para’IR: Double click the left mouse button to confirm the point on slopType : To check slop 1 we need to select slop 1 here. If we test two points on the slop then we can get gradient of the slop

Adding more test points

Click ‘Add Sweep’ to add more test points

We will check this pickup point

Here we have increased 5 more test points

3. Rapid tripping current test

The point on this flat section will be tested

4. 2nd harmonic restraint check (inrush stabilization)

5. 5th harmonic restraint check (saturation discriminator)

Set assessment

The assessment setting is used as the reference when judging the test results

For pickup and slop check normally 5% of relative error will be set

For harmonic restraint check we normally set 0.02% of the absolute error.

Set wiring

The wiring information can be preset to save the preparation time at site.

Move cursor to test item area and right click the mouse button to pop‐up the menu

Select ‘Message’ command to enter into the setting screen.

Fill in the relay terminal marks accordingly.

Here we can also make the notes

Click ‘OK’ button to confirm the setting and then we can view the wiring

If this option is selected the message for the next test item will be popping up for your reminder

With this option selected the test process will pause before proceeding to the next test item.

Set binary input

Check the binary input setting and be sure that the selected binary input setting is ‘Enable’.

Our binary inputs can automatically detect the status change for both potential or potential free contact. So there is no need to set contact type in the software

Note:

Differential relay

The current of LV side must be normalized to HV side in order get same phase shift

Conversion example: Y‐D‐11 connection