What is BS IEC 60076‑7 – Power transformers about ?
BS IEC 60076 is an international standard that discusses the loading guide for mineral-oil-immersed power transformers. Power transformers are used in AC to DC converter & DC to DC converter for ensuring high frequency and stepping voltage up & down.
BS IEC 60076‑7 is the seventh part of the BS IEC 60076 that applies to mineral-oil-immersed transformers. It describes the effect of operation under various ambient temperatures and loads conditions on transformer life.
Who is BS IEC 60076‑7 – Power transformers for ?
BS IEC 60076‑7 on power transformers applies to:
- Manufacturer of power transformers
- Electrical engineers
- Quality testing personnel
Why should you use BS IEC 60076‑7 – Power transformers ?
Power transformers are devices used for electrical transmission from one circuit to another circuit without changing the frequency. They contain an electromagnetic core and a coil wrapper. They are used in AC to DC converter & DC to DC converter for ensuring high frequency and stepping voltage up & down. Oil-immersed is a kind of voltage transformation device utilizing the oil cooling method to reduce the transformer temperature.
BS IEC 60076‑7 provides guidance for the specification and loading of power transformers from the point of view of operating temperatures and thermal ageing. It provides recommendations for loading above the nameplate rating and guidance for the planner to choose appropriate rated quantities and loading conditions for new installations.
BS IEC 60076‑7 gives the models that provide the calculation of operating temperatures in the transformer, particularly the temperature of the hottest part of the winding. This hot-spot temperature is, in turn, used for the evaluation of a relative value for the rate of thermal ageing and the percentage of life consumed in a particular period. The modelling refers to small transformers, here called distribution transformers, and to power transformers.
As a user of BS IEC 60076‑7, you can be ensured of the Loading guide for mineral-oil-immersed for power transformers.
What’s changed since the last update ?
BS IEC 60076‑7:2018 supersedes BS IEC 60076‑7:2005, which is withdrawn. It includes:
- Title has been updated from "oil-immersed power transformers" to "mineral-oil-immersed power transformers" and insulation life is updated by considering the latest research findings
- Temperature limits have been reviewed and the maximum core temperature is recommended and several fibre optic sensors are recommended for the temperature rise test
- Q, S and H factors are considered
- Thermal models are revised and rewritten in generally applicable mathematical form and geomagnetic induced currents are briefly discussed and corresponding temperature limits are suggested
- Extensive literature review has been performed and several references added to the bibliography