This paper presents a comparison of conventional single-phase water/glycol liquid and innovative two-phase cooling technology for thermal management of high power electronics automotive IGBT modules during full drive cycle. The proposed two-phase cooling system is built using conventional automotive air conditioning components (condenser, expansion valve, compressor, and vapor and liquid lines) and conventional cold plate as used for single-phase cooling, thus the design does not require the development of new technology for its implementation. 3-D numerical simulation in COMSOL and experimental results of two-phase cooling have been obtained on a prototype and compared to conventional water/glycol cooling high power electronics modules, with considerable improvement on working temperature, power transfer capacity and equalization of die temperatures during a full driving cycle. These results suggest that two-phase cooling using the same cold plates as in single-phase cooling can be used to substantially improve the performance and reliability, of EV power converters without major changes.

Most of current prosumer-energy-management approaches are focused on economic optimization by self-consumption maximization. Nevertheless, a lack of energy management strategies (EMS) that tackle different interaction possibilities among community-clustered solar plus battery prosumers has been detected. Furthermore, such active prosumer EMS may include participation in ancillary service markets such as automatic frequency restoration reserves (aFRR) through an optimized battery-energy storage-system (BESS) operation, as well as incorporating community-level energy management. In this study, an optimal EMS that includes aggregated aFRR-market participation of five solar plus battery prosumers participating in an energy community (EC), with the aim of reducing total costs of ownership for each individual prosumer is proposed. For its validation, different scenarios have been analyzed. The results show that the proposed EMS allows a levelized cost of energy (LCOE) reduction for all community members with respect to the base-case scenario. Moreover, the most profitable scenario for all prosumers is still the only PV.

This paper proposes a new approach for interconnecting Distributed Energy Resources (DERs) in low-voltage distribution networks, focusing on integrating photovoltaic (PV) generation systems and Battery Energy Storage (BES). To optimize the integration of DERs into distribution energy systems, distinct voltage profiles of customer’s nodes and energy losses along the grid have been analyzed. The applied methodology utilizes the load flow study module of the PSS/E software, in conjunction with developed Python algorithms to study several studies over 24-h periods. The main parameters analyzed include: the number of clients with a connected PV system, customer-installed power, and load profiles of all clients connected to the same source. Furthermore, two battery energy storage strategies have been examined: centralized energy storage and distributed energy storage. An independent voltage control has been implemented to assess the benefits of PV systems. The obtained results contribute to ongoing efforts toward more sustainable and efficient distribution energy systems and provide valuable insights to overcome barriers to DER penetration in low-voltage distribution networks.

Energy communities (ECs) can become a potential alternative to promote the fight against climate change. Technological progress and price reductions in recent years have made renewable energy-generation systems increasingly affordable and have generated economic benefits by reducing the value of electricity bills for community members, as well as reducing the growing environmental impact. In this context, the authors have taken Tolosa as a case study and conducted a technical and economic analysis of different possible structures of ECs (physical, virtual, with or without storage, participants with different types of consumption, etc.) by comparing them with each other. The generation capacity of the community and the optimal energy-management algorithms have been illustrated, from which the economic benefits for each member are extracted. A dynamic distribution factor is established as the basis of the algorithms, making the benefits fairer. The results obtained from this work, in addition to illustrating the economic benefits that each type of participant can receive, help to define the most appropriate community structure for each participant while highlighting the social and climate benefits that ECs can provide.

With the increasing demand of renewable energy and recent research in smart Direct Current (DC) microgrids, electric systems with high presence of power electronics are gaining momentum. One piece of evidence is the emergence of ungrounded low voltage DC (LVDC) microgrids and their energy management, which are crucial for achieving high efficiency systems. However, they are difficult to protect against electrical faults, especially against Ground Faults (GF), due to the commutation frequencies and the duality of AC and DC currents that cause a lack of selectivity in conventional protection relays. In this paper a GF detection method is proposed for addressing this issue. The method discerns between the affected zone (AC or DC) by sequentially switching a grounding resistor among the different neutrals and DC midpoints of the system. The method is based on the frequency domain analysis of the voltage waveform measured on this grounding resistor. Afterwards, in the case of AC fault, the phase-to-neutral voltages in the affected zone are measured and compared with the voltage across the grounding resistor to identify the faulty phase. In the case of DC faults, the polarity of this last voltage also allows the identification of the faulty pole. To validate the method, numerous simulations and experimental tests have been performed obtaining satisfactory results.