Research And Design Of SPWM Controller Based On CORDIC Algorithm

The development of household electronic products requires that the cost and power consumption of the matching motor should be as small as possible.The single-phase motor controlled by SPWM has many advantages such as low cost,simple structure and low noise,and has become the motor speed regulation in low-cost household equipment.Preferred.The SPWM controller can be used not only in the motor speed control equipment,but also in the inverter,which greatly improves the application range of the controller.Therefore,research on SPWM controller has important theoretical research significance and engineering application value.By analyzing the structure and working princ.iple of the full-bridge circuit,the overall design scheme of the SPWM controller is determ.ined,and it is divided into several modules according to th.e specific functions to be realized by the controller to establish and design the model.By analyzing the principle of digital sine wave generated by the traditional table lookup method,it is concluded that the traditional table lookup method occupies a large amount of chip resources in the design of integrated circuits,so that a CORDIC(Coordinate Rotation Digital Computer)based on easy integration is designed.The high-precision digital sine wave generation circuit of the algorithm is constructed,and a high-saturation SPWM(Sinusoidal Pulse Width Modulation)generation circuit is constructed based on the circuit.The specific working principle of dead time is analyzed.On the basis of the traditional dead time generation circuit,a new dead time adjustment circuit is designed,The dead time is determined only by the operating frequency of the circuit,which greatly improves the circuit.flexibility.Aiming at the problems of poor anti-interference ability and large sampling error in a single peak sampling mode,a five-stage sliding peak sampling circuit is designed to effcctively improve the sampling accuracry.Based on the above technology,a SPWM controller design integrating a high-precision digital sine wave generating module,a new dead zone adjustable module,a peak sampling module,a clock management module,a digital triangular wave generating module and a PI control module is completed.Based on the overall implementation strategy of the SPWM controller,a small-power full-bridge inverter experimental platform with FPGA(Field-Programmable Gate Array)as the core was developed and built under certain indicators,and the SPWM was designed through the experimental platform.The controller circuit system is validated.The final experimental results verify the correctness of the theoretical analysis and the feasibility of the designed controller.