Efficiency and Transfer function calculation of the Buck-Boost converter with ideal flow control Khalid Javed, Lieven Vandevelde, Frederik De Belie Department of Electrical Energy, Metals, Mechanical Constructions and Systems, Ghent University, EEDT Decision & Control, Flanders Make. Ghent, Belgium. Khalid.Javed@UGent.be Lieven.Vandevelde@UGent.be Frederik.DeBelie@UGent.be Keywords « Efficiency and transfer function calculation », « Power factor correction », « Buck-boost power converter », « Feed-forward control». Abstract The voltage regulator is designed based on a transfer function of the system pre-converter with ideal current control. This transfer function is obtained by first obtaining the system equation for the pre- converter with ideal current control. Subsequently, we look for a possible regime solution for a sinusoidal power supply and then arrive at the transfer function via linearization of the system equation around the solution in regime. The calculations are verified by using Matlab/Simulink on the system with considering two buck boost converters connected in parallel. The control scheme used in simulation is feed forward control scheme. Introduction The main goal of all types of the advancement in designing and control of the power electronic converters is to obtain the maximum efficiency. Different types of control techniques are applied for reducing all the types of power losses in a converter circuit. For a DC-DC converter efficiency, the designer should know all the different types of requirements which are responsible for losses minimization in a circuit. For this, a model design is a requirement for the estimation of DC-DC converter efficiency. This design should not only provide the efficiency of the converter for different input values but also it should help designers to improve the control techniques which are helpful in improving the efficiency of power electronic converters. The design of such model should contain a deep study of all different type of the mechanisms that causes power losses inside a system. In a DC-DC converter, there are different types of power dissipations which are because of the inductor conduction, filter capacitor losses, diode conduction and power dissipated in MOSFET. For calculating the power losses in MOSFET by using the parameters from data sheet is presented in [1] which briefly explains the switching losses as well as conduction losses of a MOSFET. For a fly back converter, the losses due to the output diode is presented in [2] in which the relationship of the losses with respect to input and output voltage is provided. The power losses due to the inductor and the identification of the scenarios which causes the inductor power losses is proposed in [3]. Reference [4] expresses a very basic method for calculating all the different types of losses in a circuit which are effecting the efficiency of the converter. From the last decade, researchers are working continuously on power factor correction PFC converters [5]–[10]. Amongst these references, [5]–[7] is about single phase analog controller for boost converter. Later on with the advancement of fast digital signal processors DSP along with analog to digital converters and PWM generator, researchers focused on moving from analog to digital control schemes [8]–[10]. The power factor correction for pre regulators and converters are performed by using advanced DSPs with more feasible control options in these references.