Development Of Synchronization Signal Source Fordistributed Power Metering Error Detectionsystem

In this era of highly informationization,electric energy has been an indispensable resource in people's live.In order to guarantee the interests of the consumers and electric power sector,the precise measurement of electricity is essential,so calibrating of electric power sector ' s power metering is necessary.A new type of digital substation consists of the voltage merging unit(MU),the current MU and digital power meter,but there is long distance between each other,so the traditional calibration device is difficult to check the electric energy metering error of this new substation.Distributed power metering error detection system using distributed(three-phase synchronous)standard signal source,is well done for the transformer substation.Due to the construction of domestic digital substation has just started,there are not many calibration devices for this kind of substation.Therefore,the study of distributed power metering error detection system has a positive effect on the construction of digital power plant in our country.This topic research,which studies the synchronization signal source of the distributed power error detection system,is the core component of it.This topic has designed and developed the synchronization signal source of the distributed power source of measurement error detection system.This source uses the GPS synchronization technology for time synchronization,uses wireless WiFi communication technology for network communication.A single source can output standard three-phase voltage and current signals at the same time,which can be used for the check of the traditional substation error.Meantime two synchronous sources,one for voltage source and one for current source,can be applied to calibration of digital substation which adopts distributed MU.The synchronization source realizes the accurate adjustment of the amplitude,phase and frequency of the output signal,realizes the switching of the output signal range,can handle the output fault,and can display the real-time output status and operating mode on the LCD.Synchronous source uses the multi-ARM architecture which is divided into waveform CPU,communication CPU and sampling CPU,and the dual-port RAM is used for the communication between CPUs.Among them,the waveform CPU first queries360,000 points of the original sinusoidal table,then uses the 16-bit high-speed DA chip DAC8820 to produce the original standard signal;the communication CPUadopts lwip protocol through the drive 100 M physical chip DP83848 and high-speed Ethernet to WiFi module to achieve wireless network communication;Sampling CPU using high-speed high-precision AD chip ADS8568 for real-time synchronous sampling of the output signal,then use FFT algorithm to calculate sampling data and output signal Amplitude-frequency and Phase-frequency characteristics.This paper begins with the research background and significance of the subject,explains the necessity of the research,analyzes the current situation of the research at home and abroad in this field,and made arrangements on the structure of the whole thesis.The second chapter introduces the theoretical knowledge and algorithms related to research,including distributed energy measurement error detection method,FFT algorithm and PID algorithm.The third chapter introduces the hardware design of the system in detail,the fourth chapter describes the system software design process.Then it introduces the hardware and software debugging of the prototype,and analyzes the test data.Finally,the article puts forward some suggestions and improvement measures for some shortcomings of the system.