Question

Problem 3 Design a parallel plate capacitor of canaritanec and yollape rating of V = 10kV. The deign objective is to store maximum amount of electrical energy for a given cost of the dielectric material Material figure of merit Fau. Material ) Cost per unit mass CS/kg 3.80 2.40 7.20 3.00 Mass density p[kg/m 870 950 2,200 Relative dielectric constant (E) 2.2 2.5 2.1 9.8 Dielectric strength ERDIMV/m) 10 20 30 Transformer oil Polypropylene Teflon Alumina 3,950 a) Propose an expression for a figure of merit that can be calculated from the material property data provided and which can be used to select the material that would best meet the stated design objective. b) Calculate the figure of merit (the units and scaling factor are not important for each material and chose the best material for your capacitor design. c) Assuming a safety factor of 2 for diclectric breakdown strength, determine the minimum required thickness of the chosen dielectric material. d) Determine the required surface area of the capacitor plates.

Answer 1

Mat	Cost/Kg	Kg/M3	Die Const	Die strength MV/M	Desin Voltage	Thk	Area M2	Volume	Weight	Cost
Oil	3.8	870	2.2	10	20	0.002	0.106451	0.000213	0.185225	0.703854
PP	2.4	950	2.5	20	20	0.001	0.046838	4.68E-05	0.044496	0.106792
Teflon	7.2	2200	2.1	30	20	0.000667	0.037173	2.48E-05	0.054521	0.39255
Alumina	3	3950	9.8	15	20	0.001333	0.015931	2.12E-05	0.083906	0.251717