Research On Charging Balance Control Of VRAL Battery For Substation

With the increasing degree of automation of substations in China,the dependence on automatic monitoring,control and alarm of secondary equipment is becoming stronger and stronger.In the event of a power outage,the importance of battery packs as a backup power source for substations is increasingly prominent.However,because the battery pack is composed of multiple single cells,it is difficult to ensure that the charge and discharge levels are completely consistent between the single cells under actual operating conditions.There is an imbalance problem that affects the life and capacity of the battery.It is even difficult to guarantee the normal function and cause irreparable losses.In addition,the battery devices used in substations at this stage are mostly the entire set of charging devices.Therefore,it is necessary to carry out a research on the charge equalization system between the individual batteries of the battery pack and propose the most A good balancing strategy,the development of a charge balancing system,to achieve the best charge and discharge state of the single battery,and to achieve balanced control are essential for reducing the polarization consumption of the battery,extending the battery life,and maintaining the stable operation of the power grid.The main research contents of this article are as follows:(1)Select BP neural network to carry out battery SOC(State of Charge state of charge,battery remaining capacity and percentage of rated capacity)estimation research,build battery SOC estimation model,take valve-regulated lead-acid batteries commonly used in substations as the research object,the battery The voltage,internal resistance and temperature are used as the input of the neural network,and the SOC is used as the output of the neural network to complete the construction of the model,and combined with the SOC measurement data of 300 sets of batteries in the 110 k V substation,using MATLAB software for related simulation verification to confirm that the neural network Accuracy of battery SOC estimation.(2)Carried out a comparative study of various battery balancing schemes,analyzed the working principles of resistance balancing,inductance balancing,capacitance balancing,transformer balancing,cuk chopper circuit balancing,and DC / DC balancing,and innovatively proposed the application of DC / DC technology to substation battery packs Equalization,and use Simulink components in MATLAB to simulate and verify each equalization plan,select the lead-acid battery module according to the type of valve-regulated lead-acid battery actually used in the substation,set its rated voltage to 2V,and perform capacitance equalization and inductance equalization With the simulation of DC / DC equalization,the structure of DC / DC equalization is relatively simple,the control is convenient,and the equalization efficiency can be guaranteed.It has advantages in the above several equalization schemes,which can be used as a subsequent substation valve-controlled lead-acid battery charge equalization Equilibrium strategy for system development.(3)Select DC / DC equalization to develop the design of the valve-regulated lead-acid battery charging equalization system,and select Freescale's MPC5634 M controller as the system main controller to design the power supply module,acquisition module and equalization circuit.At the same time,the software design of the system was carried out,mainly the main control program design and the balance system program design,and finally the design of the entire battery balance system was completed,and the reliability of the system was verified by experiments.