Effects of Control Strategies on the Assessment of Power Converter Losses in Electric Vehicle Drivetrains

Abstract

Due to their enhanced performance and absence of carbon emission, electric vehicles (EVs) are attracting much interest worldwide. Properly interfacing energy storage with power converters is crucial for the overall EV drivetrain performance and efficiency. Power converters convert electrical energy between different voltage levels and waveforms from the battery to the motor and vice versa. Variations in control schemes based on pulse width modulation (PWM) techniques directly impact losses and temperature profiles on converter power semiconductors, which are directly related to the reliability of power converters. This paper presents a simplified modeling approach to show how PWM-based control strategies impact power converter losses in EV drivetrains. The investigated drivetrain system consists of a two-level inverter interfacing with a bidirectional current boost chopper and supplying power to a permanent magnet synchronous machine. Based on electrothermal models, the influence of sinusoidal PWM method and space vector PWM method on the power converter losses and thermal stresses in power semiconductors are evaluated and analyzed. A performance comparison of different PWM methods is performed through PLECS software-based numerical simulation results.