Mig Welding Power Source Controller Based On Dsc And Fpga Simulation And Implementation,

Since the appearance of the welding inverter in 1980s, it was gradually developed and refined over the past 20 years. Now the welding inverter has become a mainstream product in the field of the welding power supplier. Generally, the inverter frequency works ranging from 20k to 100k Hz. However, the recent welding inverters are commonly controlled by the analog circuit, which restricts the output performance and the versatility of the welding inverter.With the rapid development of computer technology, the EDA technology and the digital signal process technique become practical, which make it possible to apply the digital control technique to the welding inverter.Meanwhile, if the introduction of the intelligent control policies to the control of the welding inverter is conducted, the perfect control performance is expected to be achieved, and it will make the control of the power product more precise. This paper uses two digital control algorithms: variable parameter PI and fuzzy control algorithms.To determine the control algorithms and guide the programming, this thesis set up the simulation model of the whole control system using the Simulink toolbox of the software of Matlab. However, pure PI algorithm simulation shows that it can't deal with the uncertainty of the parameters which exist in the arc welding inverter. Therefore this thesis adopted the fuzzy control and PID control technology, designed a double-loop control system, and conducted the simulation tests. Simulation results present the robustness of the intelligent controllers and the control strategies and show the feasibility of employing them to tackle the uncertainty of the parameters of welding inverter.In the implementation of the control algorithm, traditional controllers can not appeal to the high-performance system and catch up the epoch tempo due to their low velocity and long developing cycle. Improving real-time performance and reliability becomes the key point of controller design. Therefore combining EDA technique with traditional cybernetic method, the dissertation develops a new type controller based on FPGA where PID algorithm is integrated and DSC where fuzzy algorithm is integrated. Among them, control cycle of FPGA-based control system of current loopreached 8 μs. So, it can enhance the real-time performance greatly and avoid manyproblems caused by the software environments; therefore, the design efficiency and system reliability are guaranteed. Meanwhile, compared with the traditional hardware controller, the high level of integration requires fewer external circuit designs which can reduce costs. This paper provides a new way for the realization of the controller.