| The batteries of Hybrid Electrical Vehicle (HEV) are connected in series to provide a high terminal voltage. The difference of initial capacity, voltage, resistance and temperature of each battery results in some cell overcharged or over-discharged in use. Because the capacity of some battery is lower than that of others, its capacity is completely consumed in advance during the discharge. Then, it becomes a consumer in the circuit, and others provide the energy to it. As a result, whole batteries are not in duty normally, and their service life shortens. During the charging, the battery whose capacity is firstly consumed up is early charged, and others cannot be fully charged. In fact, the efficient capacity of whole batteries depends on the least capacity of one battery. Therefore, the inconsistent of characters parameters of the batteries for HEV severely decreases the performance of the vehicle. It is very necessary to equalize the batteries. Theoretical analysis and simulation on the equalization control of the batteries are completed in this dissertation. 1. After the experiment on the charge/discharge of the battery, the calculation strategy for SOC (State Of Charge) is determined and dynamical model of the charge/discharge is established. 2. The inconsistent of performance parameters of Lead-acid battery for HEV is analyzed. Then, the statistical model of inconsistent of the battery is obtained. 3. On the basis of dynamical and statistical model acquired, equalization control strategy on the charge processing is setup and the simulation on energy equalization control of charge/discharge is done. 4. Applying mathematical model of the motor expressed in terms of phase variable, Lead-acid batteries model, and the modular of software ADVISOR, the equalization system model of the batteries for HEV is established. The simulation control of the equalization system of the charge/discharge is completed by means of the inconsistent judgment and control strategy.
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