Research On Generator Frequency Signal Homology And Power Intelligent Transmitting Instrument

The accurate measurement of generator output power and frequency is the basis of operation,monitoring,control and relay protection of power system and electrical equipment.Traditional transmitting instruments have some shortcomings,such as insufficient measurement accuracy,long response time,poor anti-interference ability and low integration,etc.,which lead to generator set tripping accidents from time to time,and affect the stability of the power system.This thesis researches and develops a fast and accurate measurement and transmitting instrument of generator electric parameters based on dual ARM.It can quickly and accurately measure the frequency of generator output voltage,active power,reactive power,power factor and other key information.This information is used by the electric power system for control and dispatch.The device design includes hardware and software.In the hardware part,the measurement technology of generator frequency,power and other electrical parameters satisfying high precision and fast response is mainly studied.It mainly includes the hardware circuit design of frequency and power signal conditioning,signal acquisition,dual ARM control system,electrical parameters input and output,human-computer interaction,communication,dual power supply and the electromagnetic compatibility design of the device.In the software part,the frequency and power data processing algorithm,intelligent disconnecting identification and switching algorithm which are suitable for the generator electric parameter transmitting instrument are mainly studied.The programs design of system initialization,signal sampling,data calibration,data storage,IRIG-B code synchronization,human-computer interaction,communication and other programs are completed.In the design process,the frequency measurement method of generator output voltage with high precision and fast response is deeply studied.The frequency measurement accuracy of generator output voltage not exceeding 0.001Hz and the response time less than 50ms are realized.In view of the accuracy and real-time performance of power measurement,high-speed microprocessor(STM32F767),efficient data processing algorithm and intelligent transmission algorithm of dual CT and dual PT are adopted to ensure that the output of power measurement coincides with the trend of actual power when the instantaneous inrush current impacts.The device adopts a frequency measurement method independent of other electrical parameters measurement,and applies the measured frequency to voltage signal sampling,which ensures the accurate measurement and transmission of power and other electrical parameters when the generator output frequency fluctuates greatly.Finally,the electrical performance and safety test and electromagnetic compatibility test of the device were carried out.The device has passed the type test.A high-performance generator frequency signal homology and power intelligent transmitting instrument which meets the national grid access standard is developed.The test results show that the intelligent transmitting instrument has the characteristics of high measurement accuracy,fast response speed and strong anti-interference ability.It is of great significance for improving the frequency and power control accuracy of power system and improving system stability.