Research On Technology Of Mechanical Frequency Control For Alternating Current Generation System

Today,power grid always has a huge supplying scale,but,if there appears blackout because of malfunctions,humans will have a big financial loss.Actually,many sciences have noticed the problem,and meanwhile they have begun researching distributed network supply network equaling to alternating current microgrid generation.Because character of output energy of microgrid,it can’t connect with power grid directly or drive user load without inverter.Only by power electronics inverter and relevant control method,can microgrid output power frequency alternating current satisfying load demand and grid conditions.However,using of grid-connected inverter will induce shock and a lot of harmonic to power grid,which is the main reason why many microgrid haven’t had grid-connected actually.The paper comes up with mechanical frequency control and its control technology for power system.In another word,using metal belt mechanical contiuously variable transmission controls frequency of output power for alternating current generation system,which will realize smoothly switch between interconnection mode and island mode.Using this technology,on the one hand,can avoid the prodlems of accurately detecting electric quantity hardly and control delay of grid inverter control,and enhance quality of electric energy in grid cut,and avoid injecting harmonic pollution to power grid from using power device in inverter,on the other hand,can reduce using power electronic device with high frequency,high power and high performance,so that the microgrid cost of construction and operation reduces so much and operational reliability of mcrogrid rise so much.In one word,the technology is a brand new,even revolutionary power grid method.The research of this paper focus on electronic mechanical continuously variable transmission(EMCVT)that is characterized by low cost,high efficiency and simple structure.First,the paper analyzes structure and builds module of electronic mechanical continuously variable transmission,which include mechanical structure,working principle,process of bearing capacity,establishing speed ratio model,analyzing adjustable-speed motor.Then,for verifying that established mathematical model is right,the paper researches and simulates control system and control method according to mechanical structure of electronic mechanical continuously variable transmission and meeting the load demand,which includes specification requirement of control system for electronic mechanical continuously variable transmission,determining control project,control strategy,testing functionality of control project using mature controller.To cooperate with exploiting a dedicated transmission control unit of electronic mechanical continuously variable transmission(TCU)for frequency conversion,the paper tests drive requirement of electronic mechanical continuously variable transmission and determine the main parameters of speed-adjustable motor and clutch motor.On the basis of which,the paper designs TCU integrally with TC178 microcontroller of Inineon being core element and finishes the preliminary development.