Research And Design Of The Battery Characteristics Simulator

With more and more mobile and portable devices into People’s Daily life,batteries, as a special kind of power supply, also have a wide range of applications,especially the lithium battery, which has high power density, low self-discharge andno memory, etc. But any kind of equipment in the factory should be conducted aseries of tests to determine whether it is able to meet the needs of the people beforethey leave the factory. In the test of battery equipment, using the real battery exitsome shortcomings, such as test discontinuous, long test cycle and high cost, andthe test battery once abandoned, it will produce very big effect to the environment.At present, most testing are conducted with DC voltage source instead of realbatteries. Because the output of the battery present a highly nonlinear, so this kindof test can’t get very exact experimental results. This paper puts forward a batterycharacteristics simulator based on thyristor rectifier. The main circuit of the batterycharacteristics simulator is consisted of two groups of thyristor rectifier bridgeback-to-back in parallel. This can simulate the output characteristic of the batteryvery well, and can replace real battery in some tests to avoid some of theshortcomings of traditional test.Firstly, the characteristics of the battery and a few other important parameterswere introduced in this paper and the battery charging and discharging process forsimple analysis. Because the output of the battery are highly nonlinear，and manyfactors contributes to this, so the modeling of the battery is very difficult. Until now,a highly accurate battery model which can take into account all influencingfactors is still needed. In this paper, the existing battery modeling method isconcluded, on this basis, combining with the actual needs of subject, a suitablemodel for battery characteristics simulator called Olivier Tremblay battery model isbuilt, and compaired with the data provided by the manufacturer curve, therationality of the model is validated.In the next place, a simple comparison between PWM rectifier plus bi-directional DC-DC converter and thyristor-based battery characteristics simulator ismade in this paper. take all factors into consideration, we choose the second as thissystem of main circuit topology. The simulation model of the battery characteristicssimulator is built in the MATLAB software, and make a detailed simulationanalysis on the followed operating mode, they are constant current discharge mode,constant current charging mode, working with a purely resistive load, charge anddischarge working alternately and working with the DC motor load, verified thebattery characteristics simulator which is put forward in this paper can simulate thebattery working characteristic very well. This paper designs the hardware circuit of the battery characteristics simulator,including the choice of the power device, buffer circuit of the power device anddriver circuit, the network voltage zero detection circuit, signal sampling circuit andsome other auxiliary circuit, and at last create a hardware platform.Finally, this paper design the software portion of the entire system, at the sametime, make the experimental analysis of each circuit module. Experimentalwaveforms were collected and analyzed. Then, a summary of the entire paper ismade.