New test technologies respond to increasing demands
Reduce costs, switch to renewable energy sources, create de-centrally supplied grids, maintain high grid quality – we know that the demands made on energy supply companies and the accompanying efficiency pressures are increasing all the time. The result: human resources must be utilised extremely rationally and flexibly. This also applies for measurement and control technology, where many companies now employ all-rounders instead of specialised test engineers.
This new type of measurement technician, who can for example be found in medium-voltage substations, looks after all the important assets such as transformers, power converters, voltage converters, circuit breakers, protection equipment, primary and secondary feeds, all ground connections etc. The market offers a whole arsenal of highly developed products for each of these areas. Each one on its own is tailored for the specialised test engineer and is of a highly complex construction.
They are, however, often too complicated for universally acting measurement technicians. This is where a new product from measurement and test technology manufacturer, Megger, comes in: the multi-function test unit for power transformers and substations – TRAX – is easy to understand and to control using apps. When the app is called up for a specific test, the unit is pre-set to a suitable configuration and the test sequence is then self-explanatory. There is also a great number of measures to guarantee safety during testing (emergency stop, key switch, incorporation into external safety circuits or ground monitoring), and the recording of measurements with the TRAX unit has also been made easy for the user. If required, a specialised test engineer also has access to an expert mode with “manual controls” within the app, and therefore, has complete control over any desired test construction or any generator setting, for selecting measuring channels or for illustrating measurement results. It is not only the specialist user who will appreciate the fact that the multi-functional test unit now only requires one operating software instead of having to learn many different operating philosophies for different units. Software updates will, therefore, also be much simpler, as only one system will have to be updated in the future.
Working with TRAX
The tester selects their measuring instrument, such as the transformer ratio measurement via the app. All necessary channels become active immediately and light up in red.
Once the tester has entered the vector group of the transformer and the details of the tap-changer, the tester can then call up a connections diagram, if desired, which will tell them exactly how they should connect the TRAX unit with this particular transformer type. One press of the START button and the test will commence and, as the tap-changer has also been set up, the entire test can be carried out automatically by the TRAX unit. A winding resistance measurement can then be carried out as the next test, for example. For this, the relevant app is opened. Data already provided for the ratio measurement will be used for this test. After the test, the transformer is demagnetised, which prepares the transformer for the next test and prevents problems when the transformer is re-connected to the network. Further tests can be initiated and carried out at the same time as those already running. Upon completion, the TRAX unit will generate a summary record from the individual measurements, which can be automatically stored and saved, if required.
Basic equipment data
The unit will in principle offer all options required by a manufacturer’s or energy supplier’s measurement technician for the correct testing of power transformers and all other components in a transformer station. The basic unit generates an alternating current of up to 800 A, a direct current of up to 100 A, an alternating voltage of up to 2.2 kV and a direct voltage of up to 300 V. With the relevant accessories, the AC output capacity of the TRAX unit can be extended to 2,000 A and 12 kV. The voltages and currents generated can be controlled and measured in a highly precise way. Two pairs of relay contacts allow the tap changer or circuit breaker to be controlled remotely. The TRAX unit also offers safe measuring processes with dual ground, a three-phase analysis of circuit breakers, current and voltage converter testing and a protection relay test capability.
Monitoring & maintenance
The intelligent interaction between software, cables and accessories ensures added flexibility. No single part of the system weighs more than 32 kg – a fact that will come as a pleasant surprise to international maintenance or service engineers in particular, as the unit does not need to be transported by air freight when working abroad. The system also offers a Multilanguage option, so that commissioning or test protocols can be generated directly in the client’s language.
Megger has also geared itself to current software solution for updates and configurations. You no longer need to purchase all available functions, as the TRAX unit can be tailored to the individual needs of the user in a flexible way. If add-ons are required at a later date, it can be updated online or by means of hardware options.
- Winding resistance and tap-changer testing
§ checks at 50 V with 100 A real DC
§ adaptive demagnetisation
§ tap-changer control
§ dynamic resistance measurements for tap-changer diagnosis
• High voltage ratio measurement
§ (250 V and 2,200 V output)
• Switch box for 3 pH/6-coil measurements (option)
• 12 kV Tan Delta (loss factor) and capacitance test (option)
§ individual temperature control (ITC)
§ automatic voltage dependency detection (VDD)
• Power and voltage converter testing
• 3 pH circuit breaker analyser
§ main and resistor contacts
§ automatic substation measurements
§ battery voltage and coil current
§ stroke measurement with a transducer
• Time measurement for circuit breakers
• Relay testing
• Time measurement applications
• Phase angle measuring unit
• Ground impedance test
• 4-channel power multimeter
• 4-channel oscilloscope
For more information, please visit megger.com/TRAX