1. 研究目的与意义（文献综述）

武汉理工大学

本科生毕业设计（论文）开题报告

2. 研究的基本内容与方案

1. Mathematical model of VRB

The battery energy storage system modelhas two categories：

The first category is the ideal voltagesource and equivalent resistance series composed of basic model whichconsidered the State of Charge and the effect of improving the consideration of Thevenin model of voltage, thecharacteristics of these models are constant.

The second is ordering dynamic modelconsidering the nonlinear characteristics pf the charge and discharge process,the parameter is more complex, suitable for accuracy. The State of Chargerepresents the number of active chemical substances, as a charge and dischargestack variable. The open circuit voltage equivalent to a controlled the sourceand size of the current the loss of the stack is divided into internal andexternal pump loss. The internal loss includes reR, impedance of the reactionand simulation of the mass transfer impedance, the diaphragm, electrode andbipolar plate impedance.

The controlled currentsource pll is used to simulate the loss of the pump. The big the stack and the smallSOC, the power consumed by the pump. EC represents the capacity between theelectrodes.

The SOC of the battery:

SOC value range of 0 – 1,when SOC = 0 it means that the battery is fully discharged and when SOC = 1 itmeans that the battery is charged.

The SOC varies betweencharged and discharged.

SCO_{t 1} = SOC₁ #8710;SOC

#8710;SOC = = × #8710;t = × × #8710;t

#8710;t isthe simulation size which is the time required to fully charged the ESS underrated power. The nature of the SOC depends on the mode of the battery, if thecharge is positive the value increased if the charge is negative the valuedecreased.

Electrochemical NernstEquation:

E= E_{0 - ()}

_{E: electrode potential(V)}

_{: initialelectrode potential (V)}

R: constant gas 8.3143J/K– mol

T: temperature absolute(K), T= 298K room temperature

F: constant Faraday, for1 mol electrons, that’s 96500C/mol

N: the electron’s numberin the reaction, (1) amp; (2) might be seen as positive and negative.

Reduced ion concentration(mol/L)

Oxydationion concentration (mol/L)

Based to the Nernstequation, the positive and negative chemical reaction equation (2-1), (2-2),the open circuit voltage of the battery:

= 1.259 - ln

Known Chemical equationreaction （2-1）:

Known by chemicalequation reaction (2-2):

When the positive andnegative electrode use the same concentration of electrolyte, the kineticequilibrium reactions is

SOC _{n =} SOC _P =SCO replacedby:

V _cell = 1.259 – 0.0257ln {(

At the normal temperature,T=298K, single cell voltage is calculated by

V _{cell =} 1.259 – 0.051 × ln [

Under certain hydrogenion concentration and temperature, the single cell voltage and SOC. The batteryis made of series of M connected batteries

= M × V _cell

According to Wuhan’stemperature Nary 5W, the acid sulfuric concentration capacity is 3mol/L. thefollowing parameters of a single cell VRFB.

Table (2-2) singlebattery parameters

Ignore the loss due tothe battery pack, the single cell into a series of 100k WVRB system parametersas show in table (2-3)

Table (2-3) 100kwW VRB system parameters

Based on these data, theparameters of the battery are calculated and an approximatively model asfollow.

Open circuit voltage ofsingle cell

V _cell = 1.35 – 0.051 × ln []

When the power reachedSOC=0.2, volt = 1024V I=97.7A. the 10% charge loss includes the internal lossof 7% and the additional loss of 3%. The stack power is,

P _st = 111.11Kw

Fixed loss

P_f = P_st×1% =1.11W

2. OBJECTIVES

The studies on thestatistics of VRB system; charge and discharge density and flow rates andtemperature are examined. This paper contains a mathematical model to describeelectrical characteristics of the VRB in a simulation. The main goal of thispaper is to study the behavior and the performance of the electrical VRB model.

3. 研究计划与安排

1. schedule

week1-3: research, lecture.

week4: write and translate the report in mandarin and submit the report.

4. 参考文献（12篇以上）

1. references

1. m.skyllas-kazacos and r. g. robbins, “the all vanadium redox battery”, u.s.patent no. 849 094(1986)

2. e.sum and m. skyllas-kazacos, journal of power sources, 15(10850 179.