Dsp-based Adaptive Fuzzy Control Variable Frequency Drive System

This paper focuses on the research and application of fuzzy control method, self-adaptive fuzzy control method was tested in AC driving control system and found a satisfactory. By theoretic analysis and simulations, the influences of various parameters and structures of fuzzy controller to system performance are discussed, and a self-adaptive fuzzy control method based on self-adjusting of output scaling factor is designed. And the simulation experimentation is done to test the adaptability of the adjustor to the parameters change of rotor resistance. The result shows that self-adaptive fuzzy control has better static and dynamic performances than routine fuzzy control.The author carries on the design to the topic, in which the speed-difference vector control system is adopted as the system structure, TMS320LF2407A is adopted as the core of control circuit, a four-dot sample method is used to create the SPWM. The main loop of the system includes commutate circuit, filter circuit, inverter circuit, etc. Simultaneity, the IPM and its driving circuit as well as self-protect circuit are introduced. Control loop of the system includes simulating interface circuit, voltage and current-measured circuit as well as speed-acquiring circuit. At last, the software frame of the control system is introduced and the flow chart is given. The drive and current waves in different frequency show the system work well.Finally, the design and experiment of the SPWM has been processed on the basis of summarizing and researching the theory of SPWM (sine pulse-width modulation). Because of the natural sampling method is difficult to realize in the real-time control system, and the regular sampling method is easy to produce the larger errors, a four-dot sampling method of SPWM with asymmetrical rules has been presented. It makes the generation time and pulse width close to the nature sampling method. The principle of this method and harmonic analysis are explained. The control effect is much better by adopting this method in the above frequency conversion and timing system .