Input Current FFT Model-derived Comprehensive Comparison of Totem-pole PFC and H-Bridge PFC Converter DM EMI Performances

The paper describes the development of mathematical models for Totem-pole PFC (TPFC) and H-Bridge PFC (HPFC) and contrasts the results with simulation and experimental findings. An inner loop current controller and an outer loop voltage controller are both incorporated in the control system, which is accountable for ensuring a power factor close to unity and retains an output voltage of 400V DC. Using continuous Fast Fourier Transform (FFT) modeling, the work compares the input currents for both TPFC and HPFC converters. Total Harmonic Distortion (THD) was calculated to be contrasted with the simulated system and the experimental observations using the mathematically established input current waveshape. The design procedure for an EMI filter that will minimize differential mode (DM) noise and enhance front-end power quality is also covered in this paper. The implementation and evaluation of the 500-W TPFC and HPFC prototypes utilize 110V, 60Hz ac on the input side and deliver 400V dc at the output end with a switching frequency of 100kHz. The power factors for TPFC and HPFC are reported to be 0.983 and 0.989, respectively. The FCC class A EMI standard is met by the front-end DM EMI filter implementation, which provides the necessary attenuation.

I. Introduction

Numerous viable techniques and topologies have emerged with the increasing growth of electric mobility and the electric vehicles (EVs) charging infrastructure [1]. Maintaining a power factor close to unity is essential in the utilization of Onboard Battery Chargers (OBC) in Electric Vehicles to enhance the power quality of the grid. Fig. 1 shows the typical circuit architecture of an EV OBC, for which, various PFC topologies have been discussed in [2]–[4]. Usually, the OBC is composed of two stages: a preliminary AC/DC converter and a subsequent isolated DC/DC converter. The two most common PFC topologies, TPFC and HPFC, which are easy to implement and are capable of sustaining high operating efficiency, are the main subjects of this work. The circuit schematics of TPFC and HPFC converters are shown in Fig. 2 comprising of four transistors. References [5] and [6] provide the better understanding about the modes of operation of TPFC and HPFC converters.