Our goal is to optimize design process and to reduce transformer weight.
Starting from detailed transformer constructive data, our software generates and solves equations corresponding to the detailed hydraulic and thermal networks describing oil flow distribution and heat transfer.
The HoST Calculus features:
Global distribution of liquid flow and temperature inside the tank (between windings, core and oil by-pass)
The distribution of liquid flow and temperature inside each of transformer active parts and between outer cooling elements
The distribution of the temperatures of winding conductors, over the core and in tank walls
All thermal models are two-dimensional. The level of details is cooling duct (in the windings, core or outer cooling) or one turn of the winding.
The software covers broad variety of different transformer construction solutions.
The laws of physics are deeply embedded in the software core. It takes into account all local pressure drops, thermal buoyancy and pressure produced by the pumps. Calculates distribution of air flow and temperatures in case of AF cooled radiators, with consideration of local convection heat transfer coefficients. All physical characteristics, such as oil parameters, are considered while solving detailed thermal-hydraulic network model.
GUI enables easy input of transformer construction data. There are options to use input GUI, but also to import input data into HoST Calculus via xml files.
As a result, calculation yields detailed distribution of oil flow and temperature distribution of conductors, insulation and oil. Software gives the location of insulation hot-spot, its temperature, and the value of hot-spot factor.
The software is product of the Professor Radakovic’s expertise, and his many years of hard work and commitment to the goal of making the HoST Calculus a professional design tool. Over the years, team of motivated young engineers contributed in achieving this goal.
Relevant Publications
about the theoretical background of the detailed thermal-hydraulic model
and its applications:
Radakovic, Z., Sorgic, M. (2010):
Basics of Detailed Thermal-Hydraulic Model for Thermal Design of Oil Power Transformers,
IEEE Trans. on Power Delivery,
Vol. 25, No. 2, 790-802.
M. Sorgic, Z. Radakovic. (2010):
Oil-Forced Versus Oil-Directed Cooling of Power Transformers,
IEEE Trans. on Power Delivery,
Vol. 25, No. 4, 2590-2598.
Radakovic, Z., Sorgic, M., Van der Veken, W., Claessens, G. (2012):
Ratings of Oil Power Transformer in different Cooling Modes,
IEEE Trans. on Power Delivery,
Vol. 27, No. 2, 618-625.
Radakovic, Z., Radoman, U., Kostić, P. (2015):
Decomposition of the Hot-Spot Factor,
IEEE Trans. on Power Delivery,
Vol. 30, No. 1, 403-411.
Radakovic Z., Tenbohlen S. (2016):
Thermal model of oil power transformers with tap changer,
Turk J Elec Eng & Comp Sci,
Vol. 24, 3293-3308.
Rogora, D., Nazzari, S. , Radoman, U., Radakovic, Z. (2020):
Experimental research on the characteristics of radiator batteries of oil immersed power transformers,
IEEE Trans. on Power Delivery,
Vol. 35, No. 2, 725 – 734.
