The paper describes the digital twin of a Li-ion battery cell based on the MATLAB/Simulink generic model. The digital twin is based on measured data for constant current/constant voltage charging and discharging cycles with State of Health (SoH) up to 79%, also including fast charging. Mathematical equations used for the digital twin are obtained by 3D data fitting of measured SoH, battery capacity, and battery cell current. The input to the proposed digital twin is only the measured battery cell current, and its output includes State of Charge (SoC), SoH, and battery cell voltage. The designed digital twin is tested and compared with MATLAB/Simulink generic model and battery cell measurements for constant discharging current and dynamically generated discharging current profile. The results show significant improvement in the generic MATLAB/Simulink model.

The paper is focused on the analysis of changes in the internal impedance of the selected battery cell. In addition, the paper describes basic information about these batteries, their advantages/disadvantages and possible uses. Battery data was obtained using our own testing device, which performed long-term cyclical tests on batteries to decrease SOH. Thanks to these tests, we obtained batteries with different SOH used for further measurement and evaluation. The internal impedance of selected batteries was measured with an accurate measuring device. Based on these measured data, the analysis described in this paper was created.

Multiport power converters are used to connect various types of energy sources and loads. These sources are usually connected via DC-DC converters to a common DC bus. However, such approach requires multiple power conversions, which reduces the efficiency of the whole system. The article describes a multiport converter with a parallel connection of transformers. The proposed topology uses a smaller number of power conversions, which increases the efficiency of the whole system. Furthermore, the topology allows easy addition or removal of next power sources or loads. A new approach is also used in deriving of a converter mathematical model. The proposed control allows the transfer of energy between arbitrary converter ports. The proposed topology and its control were verified by simulation, and the results are presented in the article.

Geared servodrives are tested with different types of short-term or long-term tests. This paper presents the industrial approach to load emulation in the testing process of electrical actuators. Presented emulation method is based on the real dataset provided by the customer. This dataset is modified, processed, and then used for the calculation of a load torque reference for the drive loading actuator under test. The final implementation is done with industrial drives controlled by PLC. NI PXI was used as a graphical user interface and for data acquisition. Experimental results that confirm the correctness of the implementation are included.