IJIES-2008 VOLUME 1 ISSUE 1 - inass

In Eq.(41), the optimal duty factor is ¼. FromEqs.(38) and (41), the equivalent circuit of the conventionalconverter is expressed by the following de-Therefore, the following equation is derived:¡ÕÌ ½ ½ ÌVinS1VoutS2C 1 C 2 (37) S2 S1Figure 10. Conventional converter.Δq Τ1,VinRonVoutΔq Τ1,VoutwhereVinC 1 C 2Ï Ì ½ ¾Ê ÓÒÌ ½ ´¡Õ½ Ì ½ µ¾RonΔq Τ2,VinRonΔq Τ2,VoutVoutVinRonC 1 C 2Ï ¾Ê ÓÒÌ ½ Ì ´¡Õ Î ÓÙص ¾Ê Ë Ì ¾, the inputterminant: ÎÒÁ Ò¡ÕÌ ½ ·¡Õ Ì ¾ ¾ ¼ ½ Ê Ë ¼ (34)½¼ ¼ ½¾ÎÓÙØÁ ÓÙØ¡Õ Ì ½ÎÒ ¡ÕÌ ½ ¾½Ê Ä Á ÓÙØÒ ¡Õ Ì ½ÎÓÙØ ¡ÕÌ ¾ ½ (35) ¾ ¾Ê Ä Á ÓÙØ · ÊË Á ÓÙØ¡Õ Ì ¾ÎÒ ¡ÕÌ ½ ¾Ò ¡Õ Ì ¾ÎÓÙØ ¡ÕÌ ½ ¾ ·¡Õ¾ Ì ¾ (36)Á Ò ´¡Õ Ì ½ÎÒ ·¡Õ Ì ¾ÎÒ µÌ ¾¡ÕÌ ½ ½Ì(a) ËØØ Ì ½ (Ë ½ ÇÒ and Ë ¾ Ç)(b) ËØØ Ì ¾ (Ë ½ Ç and Ë ¾ ÇÒ)Figure 11. Instantaneous equivalent circuits of Fig.10.the other hand, in the case of ËØØvoltage Î Ò and the capacitor ½ are connected in seriesvia Ë ¾ ’s. Therefore, a stepped-up voltage ¾Î Ò isobtained in the output terminal under no load condition.The properties of the conventional converter canbe obtained as follows:In the steady state, the differential values of theelectric charges in ½ ´ ½ ¾µ satisfyIn the case of ËØØ Ì ½, ¡Õ Ì ½ÎÒ and ¡Õ Ì ½ÎÓÙØ aregiven byOn the other hand, in the case of ËØØ Ì ¾, ¡Õ Ì ¾ÎÒand ¡Õ Ì ¾ÎÓÙØ are given byFrom Eqs.(34) (36), the average currents of the inputand the output are given byÒ Á ÓÙØ ´¡Õ Ì ½ÎÓÙØ ·¡Õ Ì ¾ÎÓÙØ µÌÁ Ò ¾Á ÓÙØ (38)In Fig.11, the energy consumed by resistors in oneperiod, Ï Ì , can be expressed byÏ Ì Ï Ì ½ · Ï Ì ¾ (39)Ò Ï ¾Ê ÓÒÌ ¾ Ì ¾ ´¡Õ½ Ì ¾ µ¾ From Eqs.(34) (37), Eq.(39) can be rewritten asÒ Ï Ì ¾ ¾Ê ÓÒ´½ µÌ ´¡Õ Î ÓÙص ¾ (40)By substituting Eq.(40) into Eq.(39), the SC resistanceof the doubler circuit, Ê Ë , can be obtained by¾´½ µ ¡ Ê ÓÒ (41) (42)From Eq.(42), the power efficiency of the conventionalconverter can be given byÊ ÄÊ Ä · Ê Ë (43)From Eqs.(25) and (41), in the case of the 2 ¢ mode,the SC resistance of the proposed converter is largerthan that of the conventional converter. However, thedifference between Eqs.(25) and (41) is only Ê ÒØ .As Fig.9 shows, the difference between the proposedconverter and the conventional converter in the efficiencyof the 2 ¢ mode is very small. Furthermore, inthe conventional converter, the power efficiency decreasesstrongly by the regulation, because the conventionalconverter cannot achieve a 1.5 ¢ mode ofoperation.International Journal of Intelligent Engineering and Systems 1 (2008) 1-8 8