高倍率脉冲放电锂电池的功率输出特性

由于电池内阻和极化现象的存在，锂电池在放电的瞬间会出现较大的电压跌落，高倍率脉冲放电锂电池更是如此。为了研究高倍率脉冲放电锂电池的功率输出特性，探讨温度、荷电状态和老化等因素对电池功率性能的影响规律，定义了锂电池的功率特性曲线，搭建了高倍率电池测试平台，并从温度、荷电状态和老化3个阻抗敏感因素开展实验研究。研究方法和结论对后期开展锂电池系统的峰值功率评估和功率曲线预测有一定的指导意义。

Power output characteristics of high-rate pulse-discharged lithium battery

In order to improve the reliability of the single-reference-station based relative positioning solutions over short baselines, the multi-reference-station based relative positioning method was explored. A priori baseline information between the reference stations was integrated into the observable model, thus giving the functional and stochastic models of the multi-reference-station based relative positioning. Based on that, the closed-form formula of the ambiguity dilution of precision for the positioning was derived so that the influence of the number of reference stations on the float ambiguity precision was revealed. Then the impacts of the biases in the a priori baseline information on the integer ambiguity resolution were analyzed theoretically. It show that the integer ambiguity resolution could barely be influenced on the condition that the bias is less than 5 cm. The multi-reference-station based relative positioning method was validated with both the simulated and real data sets. The numerical results show that, increasing the number of reference stations not only improves the single-frequency ambiguity resolution success rate and convergence rate, but also restrains the biases in the a priori baseline information. For example, the ambiguity resolution success rate is still larger than 92% even when the biases of the baseline components attain 4 cm in the field tests. This contribution provides the theoretical foundation for the fast and imprecise calibration between the multiple-reference-station in special scenarios.