Computationally Efficient Coordinate Transformation for Field-Oriented Control Using Phase Shift of Linear Hall-Effect Sensor Signals

Linear Hall-effect sensors are integrated into permanent magnet motors and provide positional feedback with the advantages of compact size and low cost. Field-oriented control (FOC) is widely used in high-performance situations yet limited by its computational cost. This paper proposes a novel simplified FOC that uses the linear Hall outputs directly to obtain the coefficients required to perform coordinate transformations through linear combination; neither the computation of trigonometric functions nor the flux position estimations are required. The method is computationally efficient because it involves less latency and fewer hardware resources, when implemented on digital controllers. Furthermore, the method has been used for sensor delay compensation, which has been verified as important to eliminate direct current. The experimental results validate the feasibility and effectiveness of the proposed method with a 126 W motor under various speed and load conditions.