Study On The Power Control Of Lithium-ion Battery Pack

With the rapid development of human society, cars have become the main traffictools in people life，they bring great convenience to people life, but at the same time theyalso exacerbate the energy crisis and the environment pollution. Since the1980s, manycountries have invested a lot of manpower and material resources in the new energyvehicle development, lithium-ion battery as power source gets the pro-gaze, becauseit has the incomparable advantage in the energy, volume, life, environmental protection andso on. But lithium-ion battery pack are also many problems in the application, such as thebalance between the large-capacity lithium-ion battery pack monomer; The efficient andsafe charging technology in lithium-ion battery electric vehicle; the accurate state of chargeare calculated and displayed about lithium-ion battery. To solve these problems, bylearning predecessors made research achievements, I propose some own opinions, and theexperimental study.First, in balancing technology aspects, this paper puts forward a new connection thatdoes not add equalization circuit and can also let every single battery’s energy inlithium-ion battery pack reach the same basic.Secondly, in charging technology aspects, this paper puts forward a pulse chargingmethod which takes photovoltaic cells absorbing the sun energy transfer to lithium-ionbattery pack the highest efficiency. First, photovoltaic cells will energy through the Cukconverter absorbing constantly shift to storage energy capacitance, and then through thepulse circuits take energy stored on the storage capacitor transfer to lithium ion battery, theswitch tube control circuit of Cuk converter and pulse circuit use the PIC microcontrolleras the main control chip.Again, in state of charging estimate aspects, using a new idea, to real-time detectionlithium battery terminal voltage as the judgment the battery state of charge voltage-Ahmeasuring algorithm, and the algorithm is fixed by the weight coefficients, but also byusing this algorithm make coulometer of real-time and accurate measurement battery state.Finally, according to hardware design of the lithium-ion battery power control systemfinish PCB circuit board production, and carry out the system hardware and software test,giving the component part of the physical figure and experimental waveform figure. Theexperimental results show that the controller can achieve the balance of lithium-ion batterypack, pulse charging, real-time accurate calculation and display energy the function, to ensure the safety and reliability of the battery pack in the practical application.