Due to simplicity, efficiency, and the ability to accommodate energy storage devices, DC distribution networks have been seen as an optimal alternative to AC distribution networks, especially aboard future electric ships. The emerging distribution DC system entails new control and management techniques. Therefore, an integrated DC power distribution network aboard an electric ship is selected as the case study in this paper. To meet the requirements of such a large-scale mobile power system, a multiport solid-state transformer (SST) based on silicon carbide (SiC) switches/MOSFETs is proposed. Thus, the system embodiment can significantly be reduced. Moreover, at the DC distribution level, a high penetration of renewable generation with energy storage is allowed and a six-phase asymmetrical induction machine (IM) can directly be integrated. Simulations have been conducted based on a 2 MW shipboard distribution network. The effects of the propulsion system dynamics on the SST are highlighted as well. Finally, a 2 kW lab-scale prototype has been implemented to validate the theoretical findings.

HVDC power tapping has proven to be the appropriate solution for rural AC networks. This tapping can be achieved by using series or parallel HVDC tap stations. But, many researchers have faced some technical and economic issues when designing tapping stations with small power ratings. In this paper, many topologies of tapping converters are reviewed focusing on their designs and providing pros and cons of each topology.

Wound rotor synchronous motors (WRSMs) are emerging as a compelling alternative to permanent magnet (PM) motors in the context of electric vehicles, offering magnet-less operation and cost-effectiveness. Various techniques exist to excite the field system of synchronous motors, each presenting drawbacks. This paper investigates a self-excitation technique based on a multi-phase stator design that autonomously energizes the field winding, eliminating the need for external excitation systems or rotating transformers, thus reducing motor weight and size. The multi-phase stator generates two distinct magnetomotive force (MMF) components: a dominant flux component responsible for torque production and a harmonic component crucial for field winding excitation. Independent control of both flux components is achieved by regulating the decoupled αβ and xy sequence current components, respectively. The paper presents the mathematical modeling and steady-state equivalent circuit for this topology. Extensive testing determines the motor parameters, analyzes the relationship between xy current and field current, and examines the effects of mechanical loading and speed variations on the field current. An improved Field Oriented Control (FOC) strategy is proposed to compensate for the effects of mechanical loading due to cross-coupling between the two subspaces caused by various nonidealities. An experimental setup employing a five-phase stator is developed to validate the proposed control methodology.

Contactless power transfer to rotating shaft-mounted loads represents an innovative technology with significant potential in various automation systems, such as bottling and rotary ultrasonic machining applications. These systems typically employ rotating platforms equipped with actuators and sensors that require a stable electrical power supply. Traditional solutions such as slip rings suffer from maintenance issues, leading to the need for alternative approaches. This article introduces a novel multiphase induction machine-based drive system, which incorporates an m-phase stator winding and two rotor windings: a three-phase propulsion winding and an n-phase transformer winding. The proposed system combines a propulsion motor and a rotating transformer within a single machine core to both drive the rotor and supply power to shaft-mounted loads. The system utilizes airgap field harmonics to enable both torque production and contactless power transfer to rotor-mounted electric loads using a single m-phase inverter. Crucially, power regulation for the rotor electric loads is achieved through a rotor voltage observer, eliminating the need for direct access to the rotor circuit or additional hardware. An experimental setup has been developed to validate the proposed drive system's performance.