Estudo e desenvolvimento de um módulo auxiliar de potência aplicado a veículos elétricos

Abstract

The APM is a DC-DC converter that is vitally important in an electric vehicle as it feeds the low voltage battery from the high voltage batteries (traction batteries, which commonly operate in the 400 V range) of the electric vehicle. , which keeps the electric vehicle running and allows the operation of all low voltage loads that operate in the 12 V range. Thus, the APM can operate with a power of a few kilowatts (from 1 kW to 3 kW), which brings with it some challenges such as: high currents on the secondary side of the converter; operate over a wide range of input voltage (260 - 450 V) and output (10 - 14 V). In this context, this work proposes the study and development of a 1500 W auxiliary power module, which meets the APM requirements. To choose the topology used, a study of the main converters with galvanic isolation, operation with high currents and high efficiency, was carried out. After defining the topology of the DC-DC converter (half-bridge with isolated current doubler), an in-depth analysis of the chosen converter was carried out, describing the operation steps, determination of the converter parameters and its simulation. Afterwards, the converter with a power of 1500 W was implemented, showing experimental results for different components. From practical experimentation, it is clear that the greatest losses are concentrated on the low voltage side of the converter due to the high currents. Even so, an efficiency of 94,7% was achieved, showing a satisfactory result of the converter. Finally, an improved version of the APM is presented, seeking to integrate new elements into the module such as planar magnetic cores, use of different types of capacitors, parallel operation of semiconductors and control systems. These improvements aim to overcome previously identified challenges and further enhance the efficiency and reliability of APM.