Techno-economic Evaluation of Reduction of Low-voltage Bushings Diameter in Single-phase Distribution Transformers
The contributions of this article are the analysis and economic evaluation of the impact on tank wall losses of a diameter reduction of low-voltage bushings of pole-mounted single-phase distribution transformers. Finite element simulations of 5- to 167-kVA transformers were performed. The study was motivated when bushing manufacturers reduced diameter from 4.6 to 3.6 cm. Results show that when the diameter of low-voltage bushings is reduced, (i) load losses increase and (ii) total owning cost decreases for transformers up to 15 kVA and increases for transformers of 25-167 kVA. The insertion of non-magnetic material between bushing holes is also evaluated.
This article introduces the method of intelligent regulation to control the Buck power-electronic converter using a newly developed small-signal model of the pulse width modulation switch. The implemented method uses a fuzzy-PID controller that is tuned using the global search method of genetic algorithm. The experimental simulation results show that the used intelligent hierarchical regulation method using the GA- tuned fuzzy-PID controller, for the utilized new PWM small- signal model, produces the desired system response for performance enhancement of the electronic switching-mode Buck converter despite the occurrence of noise with comparatively high amplitudes.