Research On Fuzzycontrol With Optimization Of Marine Diesel Generator Set

As regard to the modern marine power station, the most common method togenerate power is to use diesel generator set. With the development of dieselgenerator, adding of the ship tonnage and the higher power load, the requirement ofstability and quality of electrical grid becomes more strict.In order to keep three-phase alternating current with small harmonic wave andstable voltage, the close-loop control of speed and excitation is needed. Thetraditional way is to use PID controller which need the exact model of control object.So the application of PID controller is not always practical. The fuzzy controllerdoesn’t need the exact model and can achieve better performance compared withPID controller in the field of diesel generator set control system with nonlinear,strong coupling. Therefore, this thesis mainly discusses the combination of fuzzycontrol and traditional PID controller and then uses ant colony algorithm in theoptimization of excitation system of diesel generator set.By analyzing the speed regulating system of diesel generator set, this thesisdeduces the mathematical model and then simplifies it. It also emphatically analyzesmathematical model of synchronous generator and then transfersmodel inthree-phase static coordinate by Park’s transformation. It uses5orderelectromagnetic equation in dq axes and rotor motion equation to depict the dynamicprocess of synchronous generator. By using Matlab to build simulation model, itdoes the simulation research in the start of the diesel generator with load or not, andthe application or removing of the load of synchronous generator, then analyzes theoutcome. The outcome manifests that the regulation time is a little long when addingor removing the load.It designs fuzzy PID controller of excitation of synchronous generator. Thiscontroller is constructed by parallelling the PID controller and the fuzzy controller.The input of the inference engines is the deviation of the voltage of the generatorand fuzzy quantity which fuzzes the change rate. After simulation in Matlab theoutcome manifests that compared with traditional PID controller, when loaded andunloaded, the overshoot and regulation time of diesel generator set meet the requirements of rules for classification of sea-going steel ships.Due to the subjectivity when designing the fuzzy controller, and themembership function influence the controller a lot, this thesis optimizes themembership function of fuzzy controller by ant colony algorithm for the purpose ofthe characteristic of ITAE. The simulation outcome is analyzed. When using antcolony algorithm to optimize the membership function of fuzzy controller ofexcitation of diesel generator set, the diesel generator set has better static anddynamic performance and its terminal voltage is more stable.