Study On Brushless DC Motor Controller With Regenerative Braking

With the consumption of energy and the deterioration of environment,the electric vehicle industry has been developing rapidly under the pressure.For electric vehicle,the motor control has been widely concerned as one of the three key technologies.This paper,which is based on the existing brushless DC controller and combined with the development of electric vehicles,completes brushless DC controller's feature-rich and performance optimization.Ultimately succeed in development of a regenerative type brushless DC motor controller.After In-depth understanding of the basic structure and principle of brushless DC motor,focusing on the analysis of the working state of the motor's operation and regenerative braking,choosing the modulation mode of power MOSFET at different working states and making control scheme.Designing a double close-loop BLDC speed control system,which the speed outer loop adopts fuzzy control and the inner current loop adopts PI control,with faster response and better real-time characteristics.The current limiting method is used to limit the peak value of the feedback current to a certain extent during regenerative braking which ensures the safety of rechargeable batteries.Confirming the requirements of brushless DC motor controller's function and performance for electric vehicle.Designing hardware circuit of each module by using Protel 99 SE under the guidance of the control scheme.Building a combination of integrated modules and discrete components,reducing the cost of the controller under the premise of ensuring the reliability of the hardware system.Mainly consists of five parts: the main control circuit,power supply circuit,signal isolation circuit,power circuit and a detection circuit.Software of each module is designed by using Keil MDK under the basics of the hardware circuit.A double close-loop BLDC speed control system is completed,which the speed outer loop adopts fuzzy control and the inner current loop adopts PI control in electric operation.Completing current limiting method in regenerative braking,which limits the peak current feedback.Enhancing the detection and protection of the current and voltage which improve the functions and performance of the controller furtherly.According to the results and requirements of the hardware and software of the controller,the 57BL55 motor and 80BL130 motor test bench are built.As a debugging platform,the 57BL55 motor bench tests the feasibility of controller hardware,debugs procedures and achieves its functions.As a test platform,the 80BL130 motor bench tests the reliability of controller hardware,does dynamic testing to improve its performance.The results show that the designed energy feedback type brushless DC motor controller starts steady,runs fast and achieves the regenerative during brake,which meats its function and performance requirements.