This study presents a design methodology applied to design and improve the efficiency of interleaved Buck converters. This methodology is based on a multi-physic and multi-objective optimisation to ensure well integration of the converters. Thereto, the number of cells is used as a key parameter to formalise this approach with analytical models established to offer compromise needed between the computation time and results accuracy. The proposed methodology is applied to an interleaved buck converter for automotive application to achieve the requirements as electrical, volume, efficiency and thermal constraints. It allows to find the optimal converter architecture by searching the minimum volume integration and maximum efficiency by depicting the optimal number of cells and adequate active and passive component technologies selected from a manufacturer database. This methodology is drawn up to remove the risk of feasibility on the converter configuration earlier during the design process considering multi-physic constraints.

The extensive electrification of ship power systems has become a very appealing option for the development of more efficient and environmentally friendly ships. Renewable energy sources and energy storage systems will have a key role in such systems as they can lead to fuel consumption reduction and increase of ship efficiency. In this study, analytic formulas are obtained for the estimation of system marginal cost of a ship power system equipped with photovoltaics and energy storage system and its operation is analysed from the economical point of view. The major advantage of the proposed method is that the obtained formulas require almost zero computational capacity although they provide a qualitative view of the problem not easily attainable by other conventional methods. Hence, it could be a convenient tool for the technical–economical study of such systems. In this context, it could be exploited for the assessment of a large number of ship power system operation scenarios during ship design phase.

This study proposes Lithium-ion battery aging correction state-of-charge (SOC) estimation techniques. Although the battery is aging, the SOC error estimation system maintains the setting range using a low-cost 8 bit micro-controller. The proposed method can track and correct the open-circuit voltage against capacity in the battery management system by comparing the capacity error with the coulomb counting and look-up table methods. The experimental results verify that the SOC estimation error is still lower than 3.5% after 1000 cycles. The SOC estimation verification platform verifies the Sanyo UR18650 W lithium battery. After 300 accelerated aging cycle charge–discharge tests, the test results showed that the SOC prediction precision for an aged battery is as high as 2.67%.

The more-electric aircraft (MEA) has become a dominant trend for next-generation aircraft. The electrical power system (EPS) on-board may take many forms: AC, DC, hybrid, frequency-wild, variable voltage, together with the possibility of novel connectivity topologies. To address the stability, availability and capability issues as well as to assess the performance of the power quality and transient behaviour, extensive simulation work is required to develop the EPS architectures. The study develops a fast-simulation model of active front-end rectifiers based on the dynamic phasor concept. The model is suitable for accelerated simulation studies of EPS under normal, unbalanced and line fault conditions. The performance and effectiveness of the developed model have been demonstrated by comparison against time-domain models in three-phase and synchronous space-vector representations. The experimental verification of the dynamic phasor model is also reported. The prime purpose of the model is for the simulation studies of MEA power architectures at system level; however it can be directly applied for simulation study of any other EPS interfacing with active front-end rectifiers.

Integrated grounding system (IGS) in china high-speed railway is formed through two long horizontal copper lines named run-through ground wire buried on both sides along the railway, which is also the longest horizontal grounding system in the world through the interconnection of railways. The grounding impedance measurement of IGS of high-speed railway is a novel, important problem to ensure the human and equipment safety. The placement approach of test electrodes for the grounding impedance measurement of the IGS in the roadbed section of high-speed railway was discussed by the simulation calculation and field test results in this study. Numerical analysis and measurement arrangement of IGS grounding impedance based on short-current lead wire was evaluated by analysing the soil structure, the distance of test electrodes and the ratio of measured grounding impedance and true grounding impedance. The test route was suggested that the potential electrode be placed on the opposite side with respect to the current electrode for measuring the grounding impedance. The suitable and convenient test electrode arrangement and the corresponding correction coefficients were obtained. Compared with the computer-aided calculation, the field test maintained acceptable measurement error. Thus, a useful measurement method was proposed for grounding impedance measurement of IGS.