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Brushless DC motor with the power electronics technology, microelectronics , new motor control theory and new permanent magnet materials rapidly maturing of a new motor, with high torque and the small size , simple structure , high reliability and outstanding advantages . With the brushless DC motor applications continue to expand , the motor control system design increasingly demanding, necessary to consider the cost, the control algorithm is reasonable, and it takes into account control performance, short development cycle . Reality control system design is often carried out in the case of off-line , and what kind of model to replace the actual design of the controller is to control the system designer should first address the key issues . This article first brushless DC motor system composition , mechanism of in-depth study , to seize the main dynamic characteristics of the commutation process and its pulsation characteristics , according to the commutation commutation different stages of the process , demonstrated by the different motor characteristics of the brushless DC motor system model, simplified into a simple sub-period of the state space model . Then by measuring the speed of response of the motor system , the use of improved genetic algorithm for precise identification of the model parameters . In order to test the effectiveness of the method , we designed a real-time based on the STM32 microcontroller systems, hardware platforms including microcontrollers , power driver and inverter circuit , the current detection circuit, a voltage detection, power circuit, isolation circuits , and other interface unit . Through software programming of the rotor position capture , motor starters , motor commutation , current sampling rate, the current regulation, speed adjustment , etc. Based on this platform, we need to get the model sample data , and then complete the precise identification of the model parameters . After comparison with the commonly used model experiments indicate that the sub-period model structure is reasonable, parameter identification with high accuracy. In addition, based on the model , the brushless motor speed control design simulation platform, using PID control used to verify the validity of the platform , and finally the simulation data and the comparison of the data is actually recorded can confirm that the design of the control simulation platform algorithm can be directly applied in practice .
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