A new energy ship is being developed to address energy shortages and greenhouse gas emissions. New energy ships feature low operational costs and zero emissions. This study discusses the characteristics and development of solar-powered ships, wind-powered ships, fuel cell-powered ships, and new energy hybrid ships. Three important technologies are used for the power system of the new energy ship: new-energy spatio-temporal prediction, ship power scheduling, and Digital Twin (DT). Research shows that new energy spatio-temporal prediction reduces the uncertainty for a ship power system. Ship power scheduling technology guarantees safety and low-carbon operation for the ship. DT simulates the navigational environment for the new energy ship to characterize the boundary of the shipboard’s new energy power generation. The future technical direction for new energy ship power systems is also being discussed.

Impedance mismatching can severely decrease the power transmission capacity or even invalid the control logic of wireless power transfer (WPT) systems. To eliminate the impedance mismatch caused by various factors, such as resonant parameter drift, coupling structure misalignment and control strategy, a self-adaptive mistuning correction circuit and corresponding parameter design rules are proposed to ensure the WPT system consistently operates under resonant state, accompanying the optimal power transfer ability. Moreover, a reactive compensation circuit that can create an auxiliary voltage source by the absorbed reactive power that is introduced by impedance mismatching is designed. This source can generate a new current on the coil to bring the mismatched input current back to the resonant state, according to the current superposition principle. Unlike passive impedance network that require high parameter precision and active impedance matching strategies equipped with detection and control circuits, the proposed approach can self-adaptively eliminate either undesired capacitive or inductive reactance with two additional switches and an energy-storage capacitor, improving impedance adjusting rate and providing better system robustness. The simulations and experiments are in good agreement with the theoretical analysis. This article has potential applications in harsh environments where the system impedance and coupling strength are continuously disturbed.

In this article, an original dual-receivers/rectifier reconstructed three-coil wireless power transfer (WPT) topology for battery charging application is proposed. Proposed topology consists of a transmitting coil with inductor-capacitor-capacitor (LCC) compensation network, and two receiving coils utilizing series (S) compensation network connected with the rectifier part in parallel way. Only one receiving coil is coupled with primary transmitting coil and the other tries to avoid coupling with primary transmitting coil. Then the proposed topology has the ability of load-independent constant current output under a small equivalent load value and specific parameters resonant conditions. Simultaneously, with the increasing of equivalent load value, proposed topology can realize the automatic transmission of constant current to constant voltage charging mode. No wireless communication, relays and any closed-loop strategies are needed during the conversion process. In addition, zero reactive power input can also be achieved owing to the purely resistive input impedance and system transmission efficiency get benefit from the automatic power distribution of receiver segment. Finally, an experimental platform with 2A charging current and 72V charging voltage is built to verify the theoretical analysis for proposed WPT system.

The lightweight design of the receiver plays a pivotal role in the application of wireless power transfer (WPT) technology to intelligent devices, such as unmanned underwater vehicle (UUV) and autonomous aerial vehicles (UAVs). This article utilizes frequency-variable auto-resonance technology to tackle the problems of weak antideviation capability and non monotonic control curve encountered in lightweight design of traditional series-series (SS) topology. Additionally, since this technology can maintain constant efficiency under the desired power, antideviation control can be achieved through frequency regulation solely based on input voltage and current information, eliminating the need for wireless communication. The experimental prototypes demonstrate that this study can achieve 100-W constant power transmission with a 5- $\mu $ H receiving coil, weighing only 4 g and achieving an efficiency of 90.7% under load and position variable conditions.

Non-contact wireless power transfer systems require power regulation to ensure their proper operation at rated power due to the many degrees of freedom in non-contact coupling structures. Recently, a promising technology has been introduced for wireless power transfer systems, namely, the fractional-order technology with dual power sources to construct an equivalent impedance structure with both variable resistance and reactance. Unlike other impedance matching technologies, the fractional-order technology allows for the adjustment of the equivalent impedance of the resonant network without requiring precise selection of resonant parameters. However, this technology has not been widely adopted due to the abstract concepts involved in fractional calculus theory and control logic. In this study, we employed circuit theory to comprehensively analyze the electrical implications of fractional theory and to provide a detailed description of the inner features of Cα. This study reveals the underlying correlation between control variables and the order of Cα. Additionally, it is shown that the same fractional-order circuit can display both inductive and capacitive reactance, resulting in a significant extension of the impedance adjustment range of fractional-order components. A prototype was designed and constructed to validate the proposed approach, and the experimental results closely matched the theoretical calculations obtained from the proposed approach.