This article presents a new circuit topology of a high-voltage step-up boost DC-DC converter for photovoltaic power systems. The converter boosts the low-output voltage of the solar cell to the required voltage for the load. The proposed circuit has various advantages compared to the conventional boost converters, namely a higher boost rate with low duty cycle, lower voltage stress on components, and higher efficiency. The equations of a dual-boost converter are analyzed, highlighting the advantages of the new DC/DC converter circuit topology. The operation principle is explained using the operating intervals equivalent circuits and operation waveforms. Then, mathematical and theoretical analyses of continuous and discontinuous conduction modes of the converter are presented. Losses and thus efficiency of the proposed converter are calculated using MATLAB (The MathWorks, Natick, Massachusetts, USA). Calculations are used to compare the efficiency of the proposed topology with others available in the literature regarding the benefits of decreasing cost and complexity. A photovoltaic system simulation model is developed using PSIM (Powersim Inc., Woburn, Massachusetts, USA) to validate the proposed converter. The proposed high voltage gain boost converter has been implemented for a 100-W load and tested to verify the principle of operation.

This paper presents a mathematical integrated model that simulates the coupled events causing flashover due to the deposition of soot particles on suspension insulators of high voltage transmission lines (HVTL). The model considers non-steady three-dimensional multi-phase flow of agricultural fire producing the soot particles. In addition, the model describes in detail the mechanism of the soot deposition combined with the developing of the electric field. The model equations are simultaneously solved using an iterative finite-volume numerical technique together with the indirect boundary element and charge simulation methods. The model validity and accuracy are verified through the discussion of the results for a representative case study of a 15 kV cap-and-pin insulator string. The discussion includes a comparison of the present numerical predictions for characteristics of the deposited soot layer, electric field distribution, and characteristics of flashover occurrence, with the available results in the literature.