面向直流操作电源系统的LiFePO4电池性能优化控制研究

磷酸铁锂电池电压变化范围较宽且充放电特性敏感，一般不宜简单应用于需要长期处于浮充状态的直流操作电源系统。为此，提出了一种磷酸铁锂电池在直流操作电源系统应用中的优化控制方案，根据磷酸铁锂电池工作状态，利用AC/DC充电电源优化控制电池的充放电电流大小，使电池在浮充状态下获得电池期望的充放电电流，以实现磷酸铁锂电池在直流操作电源系统中的安全高效经济应用。首先，基于直流操作电源系统指标要求与磷酸铁锂电池性能优化要求，确定其期望的充放电状态与充放电电流值；然后，根据磷酸铁锂电池期望的充放电电流值与内部等效状态，在允许的电压波动范围内调节直流操作电源系统中AC/DC变换器的输出电压，迫使磷酸铁锂电池的实际充放电电流趋于期望的充放电电流，从而优化磷酸铁锂电池的性能。最后通过理论分析与实例分析说明了方案的可行性。

Research on Performance Optimization Control of LiFePO4 Battery in DC Operating Power System

The LiFePO₄ battery has a wide range of voltage changes, and its charging-discharging characteristics are sensitive. As a result, it is not suitable to be simply applied to a DC operating power system that needs to be in a floating charging state for a long time. In this paper, an optimal control scheme for LiFePO₄ battery used in the DC operating power system is proposed. According to the working state of LiFePO₄ battery, its charging-discharging current is optimally controlled by the AC/DC charging power supply, so that its expected charging-discharging current can be obtained in the floating charging state. Accordingly, the safe, efficient and economic application of LiFePO₄ battery in the DC operating power system is realized. First, according to the specification requirements of the DC operating power system and the performance optimization requirements of LiFePO₄ battery, the expected charging-discharging current of LiFePO₄ battery is determined. Then, the output voltage from the AC/DC converter in the DC operating power system is adjusted within an allowable voltage fluctuation range according to the expected charging-discharging current of LiFePO₄ battery and its internal equivalent state, which forces its actual charging-discharging current to approach the expected value and thus optimize the battery performance. The results of theoretical analysis and a case study show that the proposed scheme is feasible.