Winning With Automated Testing
In its simplest form, automated testing is a replay of a manual test procedure that records a result. The next step includes putting together a sequence of manual tests. This, however, should not be the extent of our expectations! As you may remember, modern testing techniques for a new protection and measurement devices were reviewed in the previous third quarter issue of TSN. Automated testing is advantageous for the user due to the many settings, multiple functions and accuracy requirements of these new test objects. Benefits also extend to the traditional electro-mechanical relays and meters.
Modern tests should properly perform these complicated tests with less difficulty than common manual test methods. Given that most of these devices have been tested in a manual, single-phase fashion, the results gained from modern three-phase testing yield superior results.
So, what should a true automated test entail? Typically, test object connections are made once at setup, and they should be identical to the application method. Data and test results (text and graphics) are automatically archived and reports generated on demand without manual intervention. Mathematical models should be used for test control and calculations maximizing efficiency and reliability. Likewise, fault simulations, using the same models, are prerequisites for real world applications. (A simple ramp test does not qualify). And finally, no programming need be required to run a test, since the test object parameters define the operating characteristics. Testing the characteristic or function only requires a decision to determine the number of test points and percent error allowed from theoretical settings. This automatic test is simply added to complete the "Test Object Protocol" for the comprehensive testing of all functions and characteristics. The user may then execute one, a few, or ALL of the tests with total ease.
A true automated test will produce the following...R.E.S.U.L.T.S.
- Reliable information for both test definition and test results.
- Efficiency of the tests performed at all level, including setup, performance, and documentation.
- Satisfaction in overall test coverage and ability to eliminate errors.
- User confidence in the knowledge that testing is done right the first time.
- Libraries of test results are automatically saved for later reference.
- Time efficiency from start to finish.
- Savings in every aspect of testing -- especially in manpower costs and time.
In a future TSN issue, we will discuss how to determine the economic impact and payback period when changing to modern test set automation.
Testing A Relay's Characteristic
If you've ever wanted to test each relay "as is", review the entire characteristic and obtain the right response for each operational condition in your system, then consider the OMICRON test philosophy. Our relay testing philosophy is based on the following guidelines:
- Relay test connections must be the same as used in each application.
- The relay settings should be known and used to define the characteristic.
- The relay should be understood in each application.
- The test set should be five times more accurate than the relay under test using mathematical models to simulate the system applications and conditions.
- Computer control and test automation is essential for accuracy, repeatability, reliability, ease of use and documentation.
The ability to prove boundary limits of a relay's characteristic for all operational situations is paramount, but requires multiple test points. In geometry, two points define a straight line, and a ramp test has never defined a relay's dynamic response...period!
The need for OMICRON'S CMC Universal Test System
Determining relay protective performance reliably, based on settings and system application is, indeed, a challenge. The CMC Universal Test System was created to meet this challenge. State of the art hardware design permits accurate and precise control over all system parameters of magnitude, phase angle, and frequency in a three-phase system. In combination with the CMC software, real-time control and automated tests can be accomplished using static dynamic and transient models. The CMC is able to test any manufacturer's relay with real world dynamic and transient conditions without complex calculations and programming.
When using the CMC Universal Test System, you'll notice our philosophy immediately. The relay's theoretical characteristic is displayed, and the boundary limits are tested displaying "actual versus theoretical" results. The entire characteristic can be tested automatically using enough test points to verify static or dynamic conditions without programming. And, transient tests, from your IEEE Comtrade files, are simply read and output directly to verify the most complex system conditions against your relay.
So, if you're concerned about how you are testing relays, want to avoid problems and improve test performance, give OMICRON a call today, and discover the user-friendly environment of the CMC Test System.