The More Electric Aircraft concept offers many potential benefits in the design and efficiency of future large, manned aircraft. In this article, typical aircraft electrical power systems and associated loads are described as well as the exciting future challenges for the aerospace industry. The importance of power electronics as an enabling technology for this step change in aircraft design is considered, and examples of typical system designs are discussed.

This paper presents an overview of technology related to on-board microgrids for the More Electric Aircraft. All aircraft use an isolated system, where security of supply and power density represent the main requirements. Different distribution systems (AC and DC) and voltage levels coexist, and power converters have the central role in connecting them with high reliability and high power density. Ensuring the safety of supply with a limited redundancy is one of the targets of the system design, since it allows increasing the power density. This main challenge is often tackled with proper load management and advanced control strategies, as highlighted in this paper.

Droop control has been widely applied in dc microgrids (MGs) due to its inherent modularity and ease of implementation. Among the different droop control methods that can be adopted in dc MGs, two options have been considered in this paper: I – V and V – I droop. I – V droop controls the dc current depending on the dc voltage while V – I droop regulates the dc voltage based on the output current. The paper proposes a comparative study of V – I / I – V droop control approaches in dc MGs focusing on steady-state power-sharing performance and stability. The paper presents the control scheme for current-mode ( I – V droop) and voltage-mode ( V – I droop) systems, derives the corresponding output impedance of the source subsystem, including converters dynamics, and analyzes the stability of the power system when supplying constant power loads. The paper first investigates the impact on stability of the key parameters including droop gains, local control loop dynamics, and number of sources and then performs a comparison between current-mode and voltage-mode systems in terms of stability. In addition, a generalized analytical impedance model of a multisource, multiload power system is presented to investigate stability in a more realistic scenario. For this purpose, the paper proposes the concept of “global droop gain” as an important factor to determine the stability behaviour of a parallel sources based dc system. The theoretical analysis has been validated with experimental results from a laboratory-scale dc MG.

The idea of electric propulsion for transportation is not new; indeed, the first cars, nearly 200 years ago, were electric. However, our dependence on fossil fuels over the last 100 years is now being questioned, and as a global society, we are moving toward more-electric transportation solutions. Electric propulsion of aircraft is part of this trend, either all-electric or through a large variety of the proposed hybrid propulsion systems. This article considers some of these systems, their technological requirements, and the ongoing research and development in motors and drives necessary to make this technological change a feasible option for the future of passenger flight.

The paper considers a control solution for integration of large offshore doubly fed induction generator based wind farms with a common collection bus, controlled by a static compensator, into the main onshore grid, using line-commutated high-voltage direct current connection. The paper's main focus is a mathematically grounded study of the power system interactions. That study produced an appropriate plant model for formal control design. A design procedure is described and the controlled system is validated using power systems computer-aided design/electromagnetic transient program simulations, which confirm the high performance of the proposed control strategy in both normal operation and fault conditions

This paper proposes an improved voltage regulation method in a multisource-based dc electrical power system in the more electric aircraft. The proposed approach, which can be used in terrestrial dc microgrids as well, effectively improves the load sharing accuracy under high droop gain circumstance with consideration of cable impedance. Since no extra communication line and controllers are required, it is easily implemented and also increases the system modularity and reliability. By using the proposed approach, the dc transmission losses can be reduced and the system stability is not deteriorated for normal and fault scenarios. In this paper, optimal droop gain settings are investigated and the selection of individual droop gains as well as the proportional power sharing ratio has been described. Simulation and experimental results validate the effectiveness of the proposed method.