The Design Of PID Silicon Controller Based On FPGA

Silicon digital controller is a closed-loop control system which can control three-phase rectification, respond the change of load and ensure the security and reliability service of power supply system. The key point of this paper is the research of algorithm, the design method in FPGA and the implement method in DPWM of the theory in silicon control system, such as the algorithm of PID and fuzzy PID which combine with fuzzy theory.Silicon digital controller systems take the SCM as the principal thing which can stand out the characteristics of high clock, parallel computing and high stability of FPGA by contract of characteristics of FPGA and SCM. At the same time, rich in I/O resource of FPGA, suitable to more I/O ocassion, easy to algorithm realize and better resource expansibility make FPGA as the silicon digital controller.What we carried on for the design of silicon digital controller in this paper is as follows:Firstly, the basic knowledge introduction of silicon digital controller which includes the operating principle of three-phase rectification, the workflows and the structure of hardware platform we made by FPGA.Secondly, we finished the design and verification of incremental PID by FPGA with the foundation of analyzing the algorithm of incremental PID. The flow chart was designed by the analysis of incremental PID, and then the modules which is divided in the algorithm of incremental PID is finished by hierarchical design method.Thirdly, The algorithm of fuzzy PID is realized in FPGA by the combination of fuzzy theory and PID. The fuzzy PID controller is designed with the foundation of incremental PID and fuzzy rules which is off-line reasoning method. The dispersing rule table is elicited by the fuzzy theory in matlab, and it is deposited in the ROM database in FPGA which is elicited for fuzzy controller. By the contrast with on-line reasoning method, the rule reasoning process of off-line reasoning method is fast in speed, low in complexity and resource with the reason that the process doesn`t need to be finished in procedure.Forthly, in order to verify the effect of PID in FPGA, the inlinear and nolinear mathematic model is built and analyze the range of application by simulating incremental PID and fuzzy PID.Finally, By the analysis of DPWM resolution ratio, choosing counting method is taken as the implement method with the advantages of easy realizing and changing of DPWM by the analyzing of several DPWM methods and the operating mechanism of FPGA. According to the requirements of silicon controlling, the design realizing of dipulse DPWM in FPGA is choosen.