Buck-boost switched control without polarity reversal to regulate the production of direct current (DC-DC) in hybrid cars

Abstract

The biggest problem that electric or hybrid vehicles present today are the amount of time required to recharge their energy, hence the importance of ensuring that the charge is not lost quickly and reducing the recharging time. We propose a more efficient energy production model to maintain the charge of the battery banks in hybrid and electric vehicles so that the autonomy time increases. A direct current to direct current (DC-DC) converter was modeled, in a buck-boost configuration that can keep the voltage constant of 50VDC powering the battery bank, with input voltages ranging between 35 and 70VDC with a fixed charging current of 4A. To automatically determine the values of the discrete components of the power filter, a MATLAB® script was developed. The transfer function of the power filter controller was calculated and simulated in open and closed loops to analyze the converter's stability. The complete circuit was tested for possible variations in voltage and load current using a Pulse-Width Modulation (PWM), with a time base of 2.4 kHz. To demonstrate the ability to perform the same function of the converter in a more stable way, digital control by PWM was implemented on a Nexys 4 development board (FPGA, Field Programmable Gate Arrays). In addition, with the advantage of reducing the variations inherent in using discrete components in an electronic circuit.Herein we disclose 1. a high-level language computer program to estimate the value of the components of the power filter that performs the energy conversion; 2. the transfer functions of the system modules; 3. the simulation of the buck-boost DC-DC converter control system without polarity inversion; and 4. the simulation of the system in digital form implemented on an FPGA.