Our research

At a transformer’s terminal, oscillating overvoltages (generated when energizing a transformer, generated due to the operation of vacuum circuit switchgears, due to ground faults in the substation and lightning etc) may coincide with the transformer's natural frequencies. The subsequent built-up internal voltage inside the transformer can be well above the transformer insulation’s withstand capability. This project is to investigate the effectiveness of existing controls in transformer management against transient overvoltage in modern grids.

For transformers, one environmental concern is the audible sound generated and emitted into the surrounding, affecting nearby residents and substation staffs. This project will survey the current regulations on transformer audible sound considering the variations in legislation between states and local government if relevant. It will also survey Australian utility practices for specified maximum transformer and reactor noise levels, and transformer sound mitigation measures using sound enclosures, noise cancellation technologies and other measures. It will compare different external sound control approaches used by Australian and international utilities and compare the cost and effectiveness of these approaches.  

This project will identify the main factors needed to be considered for transformer sound mitigation and develop a guideline for use by utilitites to specify allowable transformer sound levels and to select suitable sound mitigation techniques for transformers and reactors.

Australia’s power generation is rapidly shifting from synchronous generators to inverter-connected PV and wind-powered generators. Generators do not pay for the shared transmission network which must be funded by end-use customers who already face unacceptably high network charges. There is therefore pressure on network companies to minimize additional shared network costs to accommodate new generators. As new shared network power transformers cost up to tens of millions of dollars, it is highly desirable to increase the utilisation of existing network transformers rather than replace them with higher capacity transformers when connecting solar PV and wind farms to the network.

The challenge is how to evaluate the changes in lifecycle costing of shared network power transformers when a new solar PV or wind farm connects to the network. This must compare the options of purchasing a new, higher rated, power transformer, with the option of increasing the utilisation and loading of an existing transformer and thereby defer capital expenditure.

When parts of the network become overloaded the utility has a certain time to switch load to other substations, evening out this high load which helps prevent disruption to the consumer and the premature ageing of assets. The time to respond is obviously related to how quickly a transformer becomes too hot. Vegetable oil dielectrics are known to have lesser cooling abilities than mineral oils, however paper insulation ages slower in vegetable oil. Consequently, in this laboratory-based investigation the test power transformer is used to investigate the thermal limits a utility applies to their asset fleet, to determine whether changes are required to their existing policies on how quickly they must switch load.

This project aims to investigate how to reliably and accurately measure, process and interpret PD signals from an ester fluid transformer. PD measurements will be recorded from experimental PD sources (comprising an ester fluid and pressboard insulation system) and also from ester fluid transformers including the TIC research transformer. By comprehensively analysing the measurement results, the characteristics of different types of PD activities arising from ester fluid filled transformers will be better understood. The appropriateness of current methods for using PD measurements to measure and calibrating insulation deterioration in mineral oil filled transformers will be assessed for ester oil filled transformers.

This project will deliver an outcome for TIC members to use when considering retrofilling transformers with ester fluids. It will allow TIC members to assess the transformer on the basis of its original design and construction parameters. It will make recommendations on how to record data, perform design reviews and develop prospective thermal models that allow for predicting inservice performance of the retrofilled unit.