The Function Test

The intent of the Function tab is to exercise the circuit breaker (CB) closing functionality of synchronizing relays. You can use individual test points or a table of test points.

Depending on the synchronization conditions defined in the test object and the values of a test point, the Synchronizer test module calculates the expected behavior (nominal response) of the synchronizing relay for this specific test point. If the measured behavior of the relay meets the expected nominal response, the test point is assessed as "passed". If it does not meet this nominal response, the test point is assessed as "failed".

The test points are output by the CMC test set for specific periods of time. The output times are specified in the Settings tab.

The synchronization conditions are defined in the Synchronizing Window tab of the test object (PA R A M E T E R S | TE S T OB J E C T, "Synchronizer" block) as a voltage versus frequency test area, the so-called "synchronizing window".

When a test point lies inside of this window, Synchronizer expects the CB close command of the relay to occur within the maximum synchronization time. When a test point lies outside of this window, Synchronizer expects the CB close command not to occur during the maximum synchronization time. For a detailed description, please refer to "Calculation of the nominal response in the Function tab" in the Test Universe Online Help for Synchronizer.

Some synchronizing relays only release the CB close command if the synchronization conditions are met for a certain time. This minimum

synchronization time can be defined in the Synchronizing Window tab of the test object. If a minimum synchronization time has been defined, this is also considered for the calculation of the expected nominal response of the relay. For a detailed description, please refer to "Calculation of the nominal response in the Function tab" in the Test Universe Online Help for Synchronizer.

If the time to reach synchronization is very long:

If Δf of a test point is 0 and ΔPhi is 180°, the time required to reach

synchronization (i.e. to reduce ΔPhi) is infinite. Consequently, it is impossible to reach synchronization during the maximum synchronization time. If Δf is very small and ΔPhi is very high (towards 180°), the time required to reach

synchronization depends on the actual values of Δf and ΔPhi. In this case it is as well necessary to consider the Δf and ΔPhi tolerances set in the test object. For a detailed description, please refer to "Calculation of the nominal response in the Function tab" in the Test Universe Online Help for Synchronizer.

There are three primary ways to get test points into the table.

127 1. Enter the information into the respective text boxes for ΔV, Δf, ΔPhi (Δϕ),

or V, f, Phi (ϕ), or a combination of the two.

• ΔV, Δf, ΔPhi (Δϕ): Represent the difference between the System 1 reference value and the System 2 test point.

• V, f, Phi (ϕ): Represent actual values to be output for the System 2.

• Relative: Means that the test points are stored in the test document as a percentage relative to the synchronizing window.

Once the information for a test point is acceptable, click the AD D button.

2. Position the mouse pointer in the synchronization graph (to the right).

Right-click at a point to obtain a context menu. One of the items allows you to add that test point to the test table.

3. <Ctrl> + left-click adds a point to the table immediately.

The test table has a context sensitive menu that is accessible with a right mouse click. An important feature is being able to show or hide columns to help control how much information is displayed to the person testing.

The synchronization graph also has a context sensitive menu that is accessible with a right mouse click. It allows you to select points for the test table, test points directly, and to zoom in the various areas. It can also be used to display grid lines to aid in test point selection.

TE S T A T Displays the voltage and frequency parameters of the selected test points.

AD D TE S T P O I N T The specified point is added to the test table.

ZO O M IN Permits a given area of the dV / df plane to be enlarged for more refined selection of test points.

ZO O M OU T Permits a given area to be viewed in context with neighboring areas of the dV / df plane. This is mostly used to obtain an overview of the dV / df plane.

ZO O M MO D E Changes the mode for zooming.

ZO O M AL L Permits the entire dV / df plane to be viewed. It zooms out on the chart and includes all defined test points.

SH O W GR I D Displays the markings for the dV axis and the df axis of the dV / df plane.

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Step 1: Defining the FunctionTest

1. Select the Function tab in the Synchronizer Test View.

2. Add test points to the test table using the QU I C K TE S T button.

The QU I C K TE S T button places test points at the positive and negative tolerance values of the upper and lower ΔV and Δf positions, for a total of eight.

3. Remove the four test points from upper and lower ΔV position (where Δf = 0), because the SYN3000 relay requires a frequency deviation to work properly.

Test points can be removed individually or as a group by highlighting them and clicking the RE M O V E button. Use <Ctrl> + left-click to select multiple test points. All test points for a test can be removed with the RE M O V E A L L

button.

4. Add eight other test points on either side of the Δf = 0 boundary. Place some of them within the synchronization window and some outside, as shown in the figures 5-10 and 5-11.

"Relative" checkbox:

If this option is selected, the test points are stored as a percentage relative to the synchronizing window. The checkbox toggles between relative and absolute and applies to each individual test point and not to the whole table.

Figure 5-10:

Test points for the Function tab in Synchronizer

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Figure 5-11:

Synchronization graph for FunctionTest in Synchronizer

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Step 2: Running the FunctionTest

1. Once an adequate number of test points have been defined, you can run through them in sequence. Select the PL A Y button.

2. The test points are output by the CMC test equipment for specific periods of time as specified in the Settings tab (refer to section 5.2.6).

Figure 5-12:

Test points and their assessment in the Function tab after running the test

After outputting the appropriate voltages for a test point, the test point is assessed as either passing (green "+") or failing (red "x"). The assessment is based on the expectations for the test point. Some points are expected to achieve synchronization (Nominal Response: Sync) while some are not (Nominal Response: No Sync).

For example, test points within the synchronizing window should achieve synchronization in the specified period of time if the relay is working properly.

Likewise, test points outside of the synchronizing window are expected to exceed the maximum synchronization time without achieving

synchronization. If these expectations hold true after outputting the appropriate voltage to the relay, the test point passes.

In addition to the assessment in the test table, test points are assessed as either passing (green "+") or failing (red "x") in the graph. Again, the assessment is based on the expectation.

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Figure 5-13:

Test points assessed as passed in the graph of the Function tab

3. Verify that the Synchronoscope is displayed by selecting VI E W | SY N C H R O N O S C O P E.

4. When you highlight individual test points from the test table, the

synchronoscope shows the ΔPhi (Δϕ) at two different points in time: when the CB Close command was issued and when the CB actually closed.

The ΔPhi (Δϕ) refers to the phase angle difference between the reference system and the test system.

In this manner, you obtain a visual image of the phase difference between system 1 and system 2 when the CB close command is issued (blue arrow) and finally executed (red arrow).

Figure 5-14:

Synchronoscope for an individual test point

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The reference frequency can be set to either system 1 or system 2 and defaults to system 1. To change the reference system, use the context menu in the synchronoscope (right-click).

When system 1 is the reference and f1>f2 for subsynchronous operation, the arrow for the phase difference rotates clockwise. When system 1 is the reference and f1<f2 for above synchronous operation, the arrow for the phase difference rotates counter-clockwise.

The synchronoscope can be detached from the status bar and placed as a toolbar anywhere on your desktop. To do so, click and hold the left mouse button on the small arrow in the upper left-hand corner of the

synchronoscope. While still holding the mouse button down, drag the synchronoscope until it detaches from the borders of Synchronizer and becomes its own toolbar. If you single click the small arrow in the upper left-hand corner, the synchronoscope can be expanded to fill the entire status bar, or contracted back down to a smaller size.

Step 3: Defining the test report

Select PA R A M E T E R S | RE P O R T. A dialog box appears where you can define the scope of the report.

A detailed description about defining test reports can be found in the "Concept"

manual’s section 5.2 ”Test Reports”.

Select VI E W | RE P O R T to display the test report.

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