In order to study the unique dynamic behavior of the lithium-ion battery system in the periodic high-rate pulse discharge, a frequency-domain impedance model and a dynamic extraction method of impedance parameters are proposed. Moreover, a 24 kWh lithium battery system is built to carry out the pulse-discharged cycle experiment. The harmonic characteristics in high and low frequency pulse discharge are studied by harmonic analysis method. Besides, the impedance characteristics of the 24 kWh lithium battery system under different SOC and different cycle are analyzed quantitatively. The results show some new characteristics and verify that the proposed frequency-domain impedance model and impedance extraction method are well qualified to analyze the frequency-domain characteristics and dynamic behavior of the periodic pulse-discharged lithium battery system.

For the problem of consistency decline during the long-term use of battery packs for high-voltage and high-power energy storage systems, a dynamic timing adjustment balancing strategy is proposed based on the charge–discharge topology. Compared with the traditional balancing strategy, the dynamic timing adjustment balance strategy is more suitable for the transient high-frequency pulse and high-rate output of a high-power energy storage system. It gives full play to the pulse output adjustment function of the integrated charge–discharge topology. The advantages of this strategy include improving the balance between battery groups, the operating capacity of the system, and improving the continuous working ability of the system. Combined with the work condition of the high-power energy storage system, a balance control model is established, and a cycle charge–discharge test platform of battery packs is built. The effectiveness and advantages of the balance strategy of dynamic timing adjustment are verified by the experiment and simulations. The balancing time is less than 2 min, and the voltage difference is less than 6 mv.

Bore deterioration phenomena, such as surface ablation, wear, aluminum deposition, and structural bending, severely restrict the service life and performance of electromagnetic launchers. Efficient bore inspection is necessary to study the deterioration mechanism, guide design, and health management. In this paper, an inspection system for electromagnetic launchers is presented which utilizes structured light scanning, time-of-flight, and laser alignment methods to acquire bore laser point clouds, and ultimately extracts the surface deformation of rails and insulators, as well as the straightness of the bore, through the registration of point cloud data. First, the system composition and detection principles are introduced. Second, the impacts of the detection device’s attitude deflection are analyzed. Next, focusing on the key registration issue of laser point clouds, a coarse registration method is proposed which utilizes the arc features of the rail by combining circle and parabola equations, thereby maximizing registration efficiency. Finally, the trimmed iterative closest-point (TrICP) algorithm is employed for fine registration to handle non-axisymmetric bore deformations. The experimental results show that the proposed method can detect bore surface deformation and straightness efficiently and precisely.