Research On VRLA Battery Online Monitoring System In Substation

The valve-controlled sealed lead-acid batteries are widely used in substations.Their function is to provide reliable direct current power for relay protection,automatic devices,signal circuits and circuit breaker control circuits when alternating current power is lost.The reliability of the batteries are related to the safe and stable operation of the power grid.Different types of batteries have different internal structures,different maintenance requirements,product quality defects,inexperience of inspectors,and improper maintenance methods.Many adverse conditions will lead to reduced performance and shortened life.The traditional battery monitoring method takes a long time,the process is complicated and the interval is long.The existing batteries online monitoring device cannot perform real-time remote monitoring of the batteries,nor can it form a comprehensive diagnosis and evaluation system.These factors are not conducive to discovering the failure of the batteries in the early stage,which may eventually lead to the expansion of the fault range and cause grid accidents.Therefore,optimizing the current monitoring methods and accurately grasping the status information of the batteries in real time is the key to improving the reliability of the batteries.To this end,this paper proposes a set of online monitoring system for batteries in the substation.The sensors are installed on the batteries to collect status data,and then the data will be sent to servers in the power dispatching control center through the wireless network.Users can judge the battery performance through the analysis and processing of real-time monitoring data and assist inspectors to complete the inspection of the batteries.It can not only reduce the workload of the inspectors and safety risks,but also improves the accuracy of battery performance judgment.It helps to find the battery abnormalities in time,and has obvious social and economic benefits.The main work of this article is as follows:(1)The structure of the batteries,the working principle of charging and discharging,the main cause of failure and the influence of the main parameters on the performance of the batteries have been analyzed.The voltage,current,resistance andtemperature have been determined as the main monitoring indicators of the battery online monitoring system.The prediction method has been studied,and a fuzzy neural network prediction method based on Takagi –Sugeno model has been proposed as a battery performance judgment model.(2)A set of battery on-line monitoring system based on fourth generation wireless network transmission technology has been constructed including data acquisition modules,a main controller,a wireless communication module and servers.Users can view the real-time and historical status data of the batteries through the Web client in a computer or mobile phone client.It helps to predict the remaining battery power,receive alarm information,distribute inspection tasks,upload inspection data,and manage battery basic data.(3)The online monitoring system has been tested from three aspects of hardware,function and performance to verify the feasibility of the construction plan.