The Experimental Evaluation of Simple Bidirectional DC/DC Converter with Snubber Compensation for Electric Vehicle Application

Abstract

This research discusses the implementation of a buck-boost converter which is also known as a Bidirectional DC/DC Converter (BDC) in electric vehicles with a specific focus on electric All-Terrain Vehicles (ATV). The BDC circuit was used to integrate the main battery of the ATV (Li-Po) with the secondary battery (a 25V max./8 Farad Supercapacitor bank). This is to ensure the main battery of the ATV motor safer from unstable output load currents through the charging and discharging mechanism facilitated by BDC in order to ensure it has a longer lifetime. This discussion is more focused on the charging mechanism which occurs when the BDC is in buck mode (36V to 18 V). Meanwhile, the DC motor was used as the load inductor in this BDC circuit. It is also important to note that an interruption in the current flowing either due to a switch or other components has the ability to cause a voltage or current spike in the semiconductor switch component. Therefore, a special circuit was required to be connected to the main circuit to reduce interruption and also indicates the role of the snubber circuit in reducing the spike. This paper is more highlighted on voltage spike reduction. Moreover, LTSpice simulation was applied to verify the BDC circuit design, and the results obtained were compared with a real laboratory measurement based on the ability to change the Duty Cycle on the Vout of the BDC circuit for the charging mechanism. The determination of the desired Vout was followed by a change in the parameters of the BDC circuit such as input voltage, inductor value, switching frequency, duty cycle, and power supply configuration to determine their impact on the Vout of BDC, Spike, and MOSFET's temperature. The experiments showed that the Snubber circuit was able to compensate for voltage fluctuations in the MOSFET.