A non-isolated high-power-density bidirectional dc/dc converter named multiphase interleaved with a coupled inductor is described. The proposed converter allows low current and voltage ripple, lower power losses, reduction on power component stress and magnetic volume. Moreover, the coupled inductor is applied to achieve current sharing between each leg in a simple manner, which is helpful to simplify the structure and meaningfully improve performance. Auxiliary clamp circuits are not required and can operate over a wide voltage and power range, achieve a better dynamic response and low ripple while maintaining high efficiency. This paper illustrated the steadystate operating principle under the inductor current continuous, discontinuous conduction modes and their boundary conditions in detail, the voltage and current stress of the power devices are shown, parameter design guideline, mathematical derivations and a comparison between the proposed converter and previous dc/dc converters were conducted. Finally, a 4.5 kW proof-ofconcept laboratory prototype has been designed, developed, and tested to demonstrate the performance of the proposed converter for wide load variation. The measured efficiency for the rated load was over 98 % for maximum input voltage.

This paper presents a new three-phase step-up dc-dc converter with a three-phase high-frequency (HF) isolation transformer in an average current-mode controlled closed loop. This converter was developed for industrial applications where the dc input voltage is lower than the output voltage, for instance, in installations fed by battery units, photovoltaic arrays, or fuel cell systems. The converter's main characteristics are reduced input ripple current, step-up voltage, HF transformer, reduced output-voltage ripple due to three-pulse output current, and the presence of only three active switches connected to the same reference, this being a main advantage of this converter. By means of a specific switch modulation, the converter allows two operational regions, each one depending upon the number of switches in overlapping conditions-if there are two switches, it is called R ₂ region, and if there are three switches, it is called R ₃ region. An average current-mode control strategy is applied to input-current and output-voltage regulation. Theoretical expressions and experimental results are presented for a 6.8-kW prototype, operating in the R ₂ region, and for a 3.4-kW prototype, operating in the R ₃ region, both in continuous conduction mode.

The Zero Trust concept is being adopted in information technology (IT) deployments, while human users remain to be the main risk for operational technology (OT) deployments. This article proposes to enhance the new Modbus/TCP Security protocol with authentication and authorization functions that guarantee security against intentional unauthorized access. It aims to comply with the principle of never trusting the person who is accessing the network before carrying out a security check. Two functions are tested and used in order to build an access control method that is based on a username and a password for human users with knowledge of industrial automation control systems (IACS), using simple means, low motivation, and few resources. A man-in-the-middle (MITM) component was added in order to intermediate the client and the server communication and to validate these functions. The proposed scenario was implemented using the Node-RED programming platform. The tests implementing the functions and the access control method through the Node-RED software have proven their potential and their applicability.

The modular multilevel converter is one of the most interesting transformerless multilevel converter topology intended for medium and high-voltage power conversion. Thus, as a new topology, a fewer design guidelines are presented in the literature, on the other hand there are many restrictions. This paper presents aims to be a design guide lines to project a MMC system. The minimum submodule capacitor requirement is presented as the capacitance related to the load displacement angle, operating frequency and output power. The arm inductor design include three parameters: current ripple, fault condition and circulating current. Semiconductor current stress are calculated using average quasi-instantaneous values and rms quasi-instantaneous values will be used. From the performed analysis some normalized abacus are derived and can be used as start point for a new MMC design. The results were validated using MATLAB simulation. Furthermore, experimental results based on 2.2 kW, 5 kHz switching frequency prototype are also include and analyzed.

This paper presents a new 3-phase step-up DC-DC converter with a 3-phase high frequency isolation transformer. This converter was developed for industrial applications where the DC input voltage is lower than the output voltage, for instance in, installations fed by battery units, photovoltaic arrays or fuel cell systems. The converter's main characteristics are: reduced input ripple current, step-up voltage, high frequency isolating transformer, reduced output voltage ripple due to three pulsed output current and the presence of only three actives switches connected at the same reference, this being a main advantage of this converter. By means of a specific switch modulation, the converter allows two operational regions. Theoretical expressions and experimental results are presented for a 6.8 kW prototype, operating in region R2 and for a 3.4 kW prototype operating in region R3, both in continuous conduction mode.