An Algebraic Approach for the Stability Analysis of BLDC Motor Controllers

TL;DR

This paper introduces an algebraic method to determine the maximum tolerable time-delay in BLDC motor controllers, ensuring stability and aiding in optimal controller tuning.

Contribution

It develops a novel algebraic approach using a recent stability analysis method to accurately assess time-delay effects on BLDCM controllers.

Findings

Fast PI controller tuning can reduce stability margins due to time-delay effects.

The proposed method provides precise stability conditions for BLDCM control loops.

Time-delay significantly impacts system stability when tuning for rapid response.

Abstract

This paper presents an algebraic technique to compute the maximum time-delay that can be accepted in the control loop of a Brushless DC Motor (BLDCM) speed controller before the closed loop response becomes unstable. Using a recently proposed time-delay stability analysis methodology, we derive accurate stability conditions for the BLDCM speed controller. The results of applying the new method show that tuning the PI controller for very fast response in the order of magnitude of the BLDCM mechanical time constant cause the time-delay to significantly affect the system stability.