Research And Design Of Intelligent Distribution Transformer Terminals Based On Embedded System

Currently,with the development of the distribution automation and the proposing of smart grid,some urban areas in our country have installed smart terminal equipment.They have formally entered the times of smart grid.In rural areas,however,the methods of reading meters still fall behind.It is easiy to make mistakes such as wrong reading,leak reading and wrong magnification reading while reading the meters by workers.What's more,electrical equipments are often stolen because of the lack of effective protection measures.Therefore,it is emergent and important to solve these kinds of special problems in the rural areas efficiently.The research is mainly focus on building intelligent terminals of power grid in rural areas.According to the standard of Q/GDW 614-2011 Rural Power Grid Intelligent Low-voltage Distribution Box Functional Specification and Technical Conditions and Q/GDW 615-2011 Rural Power Grid Intelligent Low-voltage Distribution Box Functional Specification and Technical Conditions,this thesis research and design the inelligent distribution transformer terminal.This tcerminal is mainly used for intelligent low-voltage distribution box.using GPRS/CDMA or Ethernet way of data communication.It treats circuit breaker in rural power grid distribution box,residual current leakage circuit breakers,switching status of reactive power compensation,working condition of distrbution transformer,measuring instrument and so on as the main control and management objects.These implement the way of monitoring,controlling and managing the electricity-related information of power grid.The functions such as remote meter reading,power anomalies alarming,load management are included.This paper designed a kind of intelligent distribution transformer terminal based on?C/OS-?embedded real-time operating system.This terminal uses a multi-task scheduling approach to arrange the implementation of data terminal collection,clock ticking,IO expansion,DL/T 645 communication,Q/GDW 376.1 communication,GPRS communication,LCD display,USB upgrade and Ethernet communication reasonably.Besides,this paper also gives a detailed analysis of power harmonic,reactive power compensation technology.This terminal has achieved single-phase compensation and three-phase compensation together of reactive power through handling affecting factors including zero-crossing detection of voltage and current,low voltage and over voltage protection.It also completes the function of manual and automatic cycle switching.