Research And Design Of Acquisition Terminal Based On Medium Voltage Power Line Communication

According to the overall development goals of China’s smart grid construction,the user’s electricity consumption is fully covered,and the users of the public network without electricity are actively sent,and the data collection between the system data and the marketing data is shared and developed in line with the distribution network automation It is very important to promote the construction of smart grid,which can realize the real-time monitoring of large users’ electricity consumption in the non-public network area.It is of great significance to promote the construction of smart grid.Based on the research of domestic and foreign power distribution equipment and the actual investigation,it is found that the main problems faced by metering and sampling terminals are low measurement precision and poor real-time communication.In view of the above problems,according to the distribution and metering equipment Of the relevant standards developed a medium voltage power line based on the special variable collection terminal,the terminal CPU controller using Cortex-M3 core,the number of work can reach more than 120 MHz,dedicated energy metering chip ATT7022 for data collection core,can be accurate The calculation of the line of electricity information.Uplink communication for the medium voltage power line communication,high security;downlink communication configuration multi-channel 485 communication,can be used with the measurement of three-phase table at the same time,two kinds of communication independent operation,do not interfere with each other.The program design of the special design of the terminal is mainly applicable to the GPRS public network communication weak or blind installation,such as poor conditions of the mountain terrain,mining,quarries,basement,etc.,can achieve high measurement accuracy,good real-time communication,Better adapted to the collection of full coverage requirements and the loss of line statistics.In the hardware circuit design side,the equipment uses the modular design idea,facilitates the later management and the maintenance,the main module has the CPU central processing unit,the equipment enters the line collection unit,the equipment outlet collection unit,the peripheral control unit,the peripheral communication unit,Reactive power compensation unit and the uplink communication unit,in addition to the CPU processing unit is necessary,the other modules can run independently,there is no interference between each other.In the software design,adding more algorithms,such as the acquisition of data to do FFT algorithm,reactive power compensation "nine zone map" algorithm.In addition,the design of the application of medium voltage power line communication as the main means of communication,need to consider the carrier communication routing problem,due to power line impedance and noise randomness,need to constantly change the frequency of communication and debugging demodulation to adapt Constantly changing line conditions.According to the above-mentioned development of medium voltage power line based on the special characteristics of the acquisition terminal,from put into operation,the middle of the hardware and software through the escalating,is now fully meet the requirements of large users of electricity information monitoring;Measurement of the different requirements,modified part of the software communication protocol,through a large number of theoretical data analysis shows that the equipment R&D program in line with the actual requirements.