Design And Study Of Acquisition Unit In Distribution Network Online Monitoring System

With the development of the social economy,the importance of power grid to the national economy increasingly highlight,and its Intelligent and rapid response to incidents grid also become increasingly important.Smart grid not only marks the power system modernization also reflects China’s overall national strength.Distribution network due to wide coverage,complex network structure,When the short-circuit fault occur,especially single-phase ground fault,its fault location has always been a problem.To help maintenance personnel to locate the fault zone,shorten failure time,Fault indication equipment is now widely used in the distribution network.For 10 kV Distribution Network,in order to reduce the loss of users caused by grid failure,achieve real-time monitor fault line,raise the level of power supply,Designs a fault indicator with wireless communication function.The paper firstly introduces the background and the present research status of fault indicator device distribution network line Monitoring System.Secondly,it introduced the fault location principle distribution network online monitoring system,and its functional structure.Distribution network online monitoring system comprises a primary station,collection unit and acquisition unit.Thirdly,designed the overall structure of the acquisition unit,and the node is divided into several functional modules.It also selects the appropriate chip and describes design ideas of the low-power node.Then it focuses on the design of hardware and software of acquisition unit.and it mainlyincludes current measurement module,voltage measurement module,flop lighting module,power module,communication modules,watchdog module and so on;Customize the communication protocol between acquisition unit and collection unit,because of Si1000 chip superior RF performance,achieve 500 M,501M,......,509 MHz nine selectable frequency communication,test the communication distance in the open outdoor environment is not less than 200 m.Finally,use the relay testing instrument and withstand voltage tester for the acquisition unit inputs fault current and fault voltage Input fault current and fault voltage to acquisition unit,doing fault indication function test.measuring the the static power consumption of acquisition unit is to 30 uA with an ammeter.So calculate the acquisition unit can secure work on distribution lines for 10 years.