Variable Sampling Effect for BLDC Motors using Fuzzy PI Controller

Background/Objectives: The variable sampling effect the response time taken to attain its speed of the motor is low whereas, response time is high. Methods/Statistical Analysis: The simulation tool includes three parts, the first is continuous time model of BLDC motors, the second is variable sampling trigger, and the next is the discrete time speed and variable sampling time constant estimator. Findings: Variable sampling systems describe a class of systems whose sensor outputs are obtainable only at some situations not specified by the sampling mechanism. In our proposed work, a fuzzy PI controller based on variable sampling for BLDC motor drives with low resolution position sensors (Hall sensors). It is not only easy to understand as the conventional PI controller, but also more robust in variable speed control. We use three PI controller based on different sampling time at the same time, a fuzzy logic controller to calculate command. The only input variable of our fuzzy logic is rotor speed of the BLDC motor, because the sampling time thus becomes a variable according to the motor speed and the response time is high. Application/Improvements: This type method used for air-conditioner, fans etc.