Research And Design Of Excitation Controller Based On LPC11c14

Excitation controller is an important part of synchronous generator excitation device,directly affect the synchronous generator comprehensive performance is one of the key factors of safety and stability of power device.But many of the small hydro power station excitation device,low reliability,backward technology,and even some small hydro power stations not installed excitation device,greatly affect the comprehensive benefits of the hydro power station.Aiming at the problems existing in The rural small hydro power station synchronous generator excitation device and according to the requirements of the chongqing countries hydro power equipment company research and development,on the basis of reading a large number of related literature at home and abroad,the research and design the excitation controller based on LPC11c14 MCU,in order to improve the rural small hydro power station for the comprehensive performance of synchronous generator excitation device.In chapter 1 a brief introduction to the synchronous generator excitation controller of domestic and foreign research present situation and task significance.While in the 1980 s,the international and domestic excitation controller into the practical phase,but in a large number of small and medium sized hydro power stations in rural areas in China has been running for decades,changing time a basic equipment and technological transformation,there is a big safety problem,the research and development in view of the excitation controller of rural small and medium-sized hydro power station,improve the comprehensive performance of synchronous generator,it is of great significance and market prospects.In chapter 2 firstly analyzes the basic composition of general excitation controller,and then according to the specific needs of the rural small and medium-sized hydro power station,the excitation controller is proposed based on LPC11c14 MCU solution.This scheme contains LPC11c14 MCU ?of the current transformer voltage transformer for ac and dc analog signal conversion of A/D conversion Module?the communication signal decompression/filter/plastic synchronous signal module ? used to receive and send first place machine command and information communication module,used for frequency,AD sampling,phase-shifting trigger,capture interrupt,and general time of the function of timer/counter module and switch quantity input/output module.In chapter 3 illustrates the excitation controller hardware design process of eachfunction module.Excitation controller switch input signal including open/stop signals,oil switch,switch output signal is mainly the excitation signal.In order to prevent interference,switch input,output,and adopts photoelectric isolation technology.System needs to collect analog signals include voltage of the machine,power grid voltage and current machine end,for these signal acquisition using DC sampling method,through the analog voltage and current transducer,the grid or synchronous generator AC signal through AC/DC converted into corresponding low voltage AC voltage signal,using the bridge rectifier circuit converts AC signal to DC signal,amplifying filter plastic processing.Synchronous phase shifting trigger unit by the frequency measurement unit,synchronous phase shifting pulse forming unit,pulse power amplifier unit.In order to reduce the harmonic guarantee good waveform,the principle of phase shift touch hair crystal thyratron is adopted to implement trigger pulse.Excitation power unit adopted single phase half controlled bridge rectifier circuit.The design of the communication unit using LPC11c14 provided by RS232 interface,realize the excitation controller and HMI ET050 communications.In chapter 4 illustrates the excitation controller of each function module of the software design process.Software modules,including system initialization module? power calculation module?unit control module?synchronous signal capture interrupt service program?A/D conversion?interrupt service routines and synchronous phase shifting trigger the interrupt service routine.System initialization module to complete the system clock of LPC11c14,GPIO,UART,ADC,timer initialization;Power calculation module based on ADC sampling value computer terminal voltage?active power?power grid voltage and reactive power ?excitation current and power value;Unit control module based on PID algorithm to control the voltage of the machine;Sync signal capture interrupt service program to complete the frequency measurement and AD start-up of synchronous generator and some of the initialization function.A/D conversion interrupt service routine mainly completed these analog measurement.Synchronous phase shifting trigger the interrupt service routine by timers to realize the synchronous pulse trigger.In chapter 5 excitation controller for laboratory test and field running test.Test results show that,the hardware and software of corresponding system stability ? accuracy ?security ? scalability and maintainability are high,various functions meet the design requirements,and can run very well in the scene.In chapter 6 summarizes and puts forward the further improvement ideas.