Hardware accelerated Decoupled current control in Active Front End Converters for V2G applications

Abstract:
The aim of this work is to investigate the benefits achievable by implementing current vector control strategies on a specific hardware accelerator based on CORDIC (COordinate Rotation DIgital Computer) algorithm embedded in a mixed-signal MCU. The possibility to perform faster and more accurate reference frame transformations allows to mitigate the detrimental effects in the control structure related to the sampling of the electrical quantities and quantization of the trigonometrical functions. As a case study, the implementation of a decoupled current vector control in a bidirectional AC/DC power converter connected to the grid (Active Front End) has been considered, paying attention to the power quality performance of the system. Reference frame transformations performed by exploiting Look-up-Table (LUT), Floating Point Unit (FPU) and CORDIC solutions are compared by taking into consideration the resource consumption, the speed and the harmonic content of the input current waveforms. The three considered techniques have been implemented on a new 32bit microcontroller, based on ARM® Cortex®-M4 core, STM32G4 with embedded CORDIC hardware accelerator.