Modeling and Control of Negative output Triple-Lift Luo Converter Using Fuzzy Logic Controller

N.Dhanasekar, Dr.R.Kayalvizhi

The voltage lift technique is a popular method widely applied in electronic circuit design. Since the effect of parasitic elements limits the output voltage and power transfer efficiency of DC-DC converters, the voltage lift technique improve circuit characteristics. This technique has been successfully applied for DC-DC converters resulting Luo converters.  Negative output Triple-Lift Luo converters are another series of new DC-DC step-up (boost) converters, which were developed from elementary Luo converter using the voltage lift technique. Triple lift LUO circuit is derived from negative output elementary Luo converter by adding the lift circuit three times. These converters perform positive to negative DC-DC voltage-increasing conversion with high power density, high efficiency and cheap topology in simple structure. Since the power electronic converters become very complex, soft computing techniques are proper choice for controlling these systems. The classical control methods employed to design the controllers for Luo converters depend on the operating point so that it is very difficult to select control parameters because of the presence of parasitic elements, time varying loads and variable supply voltages. Conventional controllers require a good knowledge of the system and accurate tuning in order to obtain the desired performances. A Fuzzy Logic Controller (FLC) which is one of the soft computing technique has been developed for the control of Triple-Lift converter to achieve  good dynamic performances i.e. minimum value of rise time, settling time and peak overshoot in the presence of input voltage variations and load changes and invariant dynamic performance in the presence of varying operating conditions. The proposed technique is evaluated on a Luo converter under different operating conditions by using MATLAB - SIMULINK software. The results are presented and analysed.