LONDON UNDERGROUND
T OMICRON: automated testing to ensure
the quality of the protection system he quality of the
protection system has a direct influence on the
performance and stability of any electrical power system.
The effectiveness of the protection provided in rail infrastructure plays a vital role in the economic success of the system.
Question: can the quality of the protection system be sustained or even improved, when the availability of staff for relay evaluation, commissioning and routine testing is decreasing and, on the other hand, the protection devices and the protected networks and equipment are becoming more complex?
Could we substantially improve the situation by increasing the productivity of the remaining experts through automation and standardisation?
The answer to both these questions is yes! Automation and standardisation can save the relay experts’ time and allow them to concentrate on the continuous improvement of the protection system through solving and analysing actual operational problems, rather than “re-inventing the testing wheel”. Furthermore, automation not only reduces the time taken, it can even increase the depth of testing, improving not only its efficiency but also its quality.
The ease of use of automatic test plans facilitates thorough evaluation not only during commissioning and periodic testing but also after relay- firmware updates or changes in the relay’s parameterisation. Benefits which have led to
Oct/Nov 10
an increasing focus on test automation and standardisation.
What is recommended for test automation?
Standardisation of relays and their parameterisation is the key to successful test automation and helps the user to handle their complexity. For standardised protection, an automated test plan comprising a test sequence and test instructions can quickly prove its worth.
However, complete standardisation is hard to achieve. A test automation system has to provide the flexibility and tools necessary to quickly and easily adapt standard test plans to fit non- standard applications.
A relay has to be tested using its actual settings. Testing a relay to factory default settings or other amended parameters, does not guarantee that it will function correctly when the correct settings are applied. Automated test plans have to adapt automatically to fit the actual
relay settings, instead of making it necessary to manipulate the relay to fit the test plan.
Relays should be tested using the settings calculated in their setting sheets. Simply downloading the settings file directly from the relay to the test software and then using it for the test, prevents the system from detecting any discrepancies between the intended parameters and those actually applied to the relay. For this reason, the standardised automatic test plan should have interfaces to the relay settings sheet rather than directly to the relay.
The automatic assessment of test results to ensure the relay is performing according to its specified tolerances, holds many benefits. However, this can never fully replace the scrutiny of a relay expert. Clear graphical representation of the results is necessary to allow the engineer to quickly assess the plausibility of the results. Once a problem is found, whether in the relay itself, a wrong setting or even an incorrect test plan,
it is important to have the appropriate analysis tools and support to quickly locate and eliminate the source of the error. These tools should include; transient recording, wiring checking tools and measurement functions.
Automated testing provides good documentation and visualisation, with event recordings and graphics available for all of the testing steps. Repetition of any failed tests must be possible without the necessity to re-run the whole testing process, allowing fast identification of the cause of the problem.
Through its automated testing solutions, OMICRON meets all of these criteria and has combined speed and effectiveness, whilst providing the means to readily diagnose any problems identified during the process.
Its commitment to innovation and to satisfying the needs of the engineer is evident in the outstanding features and quality of its testing equipment.
rtm29
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100