| Valve-regulated lead-acid batteries(VRLA)are widely used in power systems,communication systems,transportation systems,emergency lighting and other fields due to their high reliability.In substations,VRLA batteries play a vital role as a backup power supply for DC power supply systems,which is closely related to whether the substations can operate reliably and stably.When the DC system loses AC input,it can only rely on the battery pack to provide DC power for these secondary devices,so it is particularly important to ensure that the battery pack can work normally.The traditional battery maintenance method only relies on manual use of a discharge instrument to perform a check discharge test,which not only wastes the discharged electrical energy,does not comply with the national "energy saving and emission reduction" policy,but also lacks accurate comprehensive analysis technology,unable to troubleshoot problems and problems in time.Therefore,it is of great significance for the safe and reliable operation of the substation to realize the remote online inverter grid-connected discharge method of the battery.This article first gives a general introduction to the various discharge systems of the battery,reflecting the advantages of energy saving and safety of the grid-connected discharge method.The grid-connected discharge system,phase-locked loop technology and SPWM modulation technology are analyzed in detail.The simulation model of single-phase grid-connected inverter is built under Matlab/Simulink environment,and the expressions of grid-connected current based on PI and quasi-PR control method with or without voltage feedforward compensation are given respectively.According to the steady-state error,Anti-grid interference characteristics and controller characteristics are comprehensively analyzed.The comparison of simulation results proves the feasibility of introducing quasi-PR adjustment into the grid voltage feedforward control technology.Then,on the basis of theoretical analysis,the selection of power switching devices and filter inductors was deduced,and the hardware circuit design and software design of the inverter grid-connected discharge unit were completed,and the battery inverter discharge device was developed.Finally,the battery remote monitoring and management application software was built,combined with the Socket-based remote monitoring technology,the battery pack data during the discharge process was saved to the server in real time,and the comprehensive analysis of the battery data was automatically completed to achieve intelligent management and real-time monitoring of the battery pack.Performance status,with practical application effects. |
PDF Full Text Request