This paper proposes a new control algorithm that improves the dynamic performance in distributed maximum power point tracking systems. Systems with these architectures allow to increase the photovoltaic power harvested in case of partial shading and irradiance mismatch. The classical approach adopts distributed DC/DC power electronics and control without any centralized action, which makes difficult to know whether the system is working on its optimal operating point or not. The new control algorithm presented in this paper exploits the benefits of the vectorial multi-variable perturb & observe logic and acts on the control sequence under varying irradiance conditions, reducing voltage stresses at the DC/DC converters output terminals. In addition, the matching with the DC-bus voltage control is discussed, providing a centralized control to the overall system, a fact barely addressed in literature. Simulation results and experimental measurements validate the proposed approach showing improved dynamic performance and system stability.

This paper presents the analysis, control and implementation of the interleaved three-port boost converter. The scope of this paper is the interfacing of photovoltaic systems that include storage. A new symmetrical PWM modulation strategy that prevents unwanted switching states without requiring external circuitry is presented. This modulation allows for proper sampling of the measurements, increasing thus their accuracy. Large- and small-signal models of the interleaved and non-interleaved three port boost converters are presented and transfer functions are derived for control design purposes. The different currents in the converter are controlled using control loops that govern the behavior of the converter. These loops are intuitively designed by treating them independently. With the proper loop bandwidth selection, the converter achieves fast response and good reference tracking and is suitable to interface photovoltaic and storage systems with different kinds of loads. The presented models, modulation and control loops are validated through simulation and with experimental results.

This paper proposes an approach for analyzing the benefits that partial-power-processing-based converters can bring to fully electric maritime applications. With the aim of making the system modular and scalable to different powers/energies, series-connected partial power converters are proposed. Serializing these converters entails significant overvoltage issues, and this paper tackles them for one series-connected module failure case. A reliability analysis has been carried out considering that the components of the battery system follow an independent and identical distribution in terms of failure probability. Furthermore, a redundancy factor has been added to allow a certain failure rate in what is known as a fault-tolerant system. Finally, to demonstrate the high efficiency of partial power converters, a 3 kW prototype is tested at different working points that model the charging process of a battery. The experimental results show a peak efficiency of 99.36%.

This paper presents a flexible and scalable battery system for maritime transportation, integrating modular converters and hybrid battery technologies that are effectively implemented in real-world scenarios. The proposed system is realized with modular DC-DC converters, which do not require complex design and control or a high number of components and combine high-power (HP) and high-energy (HE) battery cells to optimize the energy and power requirements of vessel operations without oversizing the energy storage system. Moreover, the modular design ensures flexibility and scalability, allowing for easy adaptation to varying operational demands. In particular, the system topology, control mechanisms, and communication protocols are explained in this paper. The concept has been validated through simulations and real-scale laboratory tests, demonstrating its effectiveness. Key results highlight the system’s ability to maintain the DC bus voltage while operating at high efficiency (ranging from 97% to 98%) under different load conditions, supported by reliable and demanding real-time communication using the EtherCAT standard. This real-time capability has been validated, and related results are presented in this paper, showing a synchronization accuracy below 200 ns between two modules and a stable control at a cycle time of 400 µs. This approach offers a promising solution for reducing greenhouse gas emissions in the maritime industry, aligning with global sustainability goals.