Basic SEPIC Converter shown in fig l.Here AC converted into DC using diode bridge rectifier.SEPIC convert the power in two stage. First ac convert into dc and dc converted into ac. It has the following disadvantage.
• Requires extensive passive filtering to improve the power factor.
• There is a tradeoff between output voltage choice power factor.
• Lower efficiency
• Large conduction loss due to large no of diode.
• Input current ripple.

Methods/Statistical Analysis
• First to design Bridgeless SEPIC Converter. To design (L1,L2,C1 and C2)value.
• To set output power switching frequency and current ripple.
• To choose the diode and MOSFET.
• Simulate the circuit diagram using Matlab
• To control the voltage using voltage control.
• To control the power factor using current controller.
• Using fuzzy logic controller to provide fast response.
• To reduce the size of the converter and controller.
• Improve the efficiency of the converter.
• Implement the hardware of Bridgeless sepic converter.
• Compare simulation and Hardware Result.

Advantage
• Reduces the THD
• Improves the power factor of the operation.
• Increase the gain and reduce the switch voltage stress. And high efficiency.
• Lower conduction loss due to 2 MOSFET devices.
• Lower voltage stress due to fewer components.
• Small size.
Application
• Grid application.
• Biomedical Industries.
• This converter used to drive dc motor and BLDC motor.
• Used for Air-conditioner.
• Used for LED application.
• Fuel cell application
Design Calculation of Bridgeless SEP1C Converter Circuit
The fundamental operation of the SEPIC converter is, at the point when the switch Si is. turned on, the inductance Li is charged, in the meantime the inductance L2 reads energy from the capacitance C2.The output Capacitance Co supplies the load. At the point when the MOSFET switch SI is turned of£ Li charges Ci and also supplies the current to load. L2 is connected to the load.

Using the equation (1),(2),(3) and (4) ,the SEPIC Converter is designed for a constant link voltage Vom =60V , Vin= 195 V to 230V, I=2.5A, Ll=L2=L=330mH.
The Proposed system Bridgeless SEPIC circuit is shown in Fig 3. In this proposed system, there is single MOSFET switch replacing the two MOSFETs, which helps to reduce high conduction loss and reduce the size of the converter. In this proposed to reduce the complexity of controller circuit. The closed loop of Bridgeless SEPIC converter circuit shown in Fig 5. In this system has two loop control method. One is outer layer (voltage control) and another one is inner layer (current control).voltage control is used to control the output voltage distabusion

Bridge less SEPIC Converter output wave form
The proposed system is simulated using MATLAB / Simulink. The input voltage is changed from 195V to 230V (normal supply voltage) and the power factor, output voltage, output current readings are taken and tabulated in Table I. The tabulated values are clearly showing, the power factor is maintained near-unity with less voltage and current ripple.
CLAIMS
single stage Bridgeless SEPIC converter has been proposed and verified with MATLAB simulink and the results are compared with traditional SEPIC. The main advantage of the Bridgeless SEPIC Converter is proved as, power factor reaching near-unity with low Voltage stress, low Total Harmonic Distortion under input voltage variations. The study is also proving that, the proposed circuit would be more suitable for low power applications