IoT-Monitored and Controlled Isolated Bipolar DC-DC Converter for Electric Vehicle Battery Charging System

Srinivasan P., N. Sankar Ram, M. Sadhasivam, D. Kabilan

Abstract


With the increasing popularity of electric vehicles (EVs), there's a rising demand for advanced power conversion systems that boost efficiency, reliability, and safety in charging batteries. This research presents the development of a specialized isolated bipolar DC-DC converter designed specifically to enhance the integration of energy storage in electric vehicle battery charging systems. The bipolar power outputs, essential for ensuring balanced charging and increasing the lifespan of the batteries, will be stable as well as efficient due to switching functions controlled by the converter using the dsPIC30F2010 microcontroller. To enhance monitoring features in the main control unit, the system includes an ESP32 microcontroller, based on IoT. With this arrangement, you can keep an eye on key battery metrics like voltage and temperature in real time, all thanks to wireless technology. This IoT-connected system not only boosts clarity in how charging works but also helps manage issues by sending out warnings for problems like overheating or too much voltage. This monitoring system enhances battery safety and extends its lifespan during operation. Isolated design gives this converter the advantages of increased electrical safety and interference reduction, making it perfect for fragile automotive environments. In simulation, the converter stepped up a 50 V input to 320 V DC, delivering a battery current of 85 A at 80.6% SOC, verified under resistive loading with a 10 kHz switching frequency. A FOPID controller provided precise voltage regulation and stable operation across varying duty cycles. In hardware implementation, the prototype achieved output regulation between 12 V–34 V at switching frequencies up to 25 kHz, with efficiency exceeding 90% and stable thermal performance under load variations. Real-time monitoring of battery voltage, current, and SOC% was realized through the Blynk IoT application, providing predictive fault alerts against overvoltage, overheating, and abnormal charging patterns. Hardware-based implementation in real conditions clearly demonstrates its practical application and efficiency. This converter combines strong power electronics with smart control and monitoring, improving EV charging systems by tackling both technical and practical issues related to high-performance and safe battery management systems.

Keywords


IOT; Isolated DC-DC converter; Electric vehicle; ESP32 microcontroller; Blynk application

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References


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DOI: https://doi.org/10.64289/iej.26.0103.9937356