Power Quality Evaluation of Six-Step Commutation Brushless DC Motor Implemented on 32-Bit ARM Cortex Microcontroller

Abstract

Electronic speed controller (ESC) is an important sub-system in drones, which is used to control and regulate the speed of its electric motor. For low-cost drones, simple control scheme such as six-step commutation brushless DC (6S-BLDC) control is used. This paper presents an analysis method to study the power quality delivered by 6S-BLDC control based on discrete Fourier transform (DFT) over the measured motor current. As proof of concept, a 6S-BLDC ESC implemented in a generic 32-bit microcontroller is studied. Findings show that the power quality and motor dynamic performance of 6S-BLDC ESC depends on motor speed, gate driver modulation period but is relatively insensitive to microcontroller supply voltage and clock frequency used in the prototype.