Focusing on the design of magnetic couplers for UAV wireless charging, this chapter addresses various design strategies for optimizing power transfer efficiency. It covers the design of pickup coils, including embedded lightweight squirrel-cage coils, hollow pickup coils suitable for in-flight UAVs, and onboard integration-based coils. The chapter also examines different magnetic coupling structures, such as orthogonal magnetic couplers, free-rotation asymmetric couplers, and compact omnidirectional magnetic structures. Each design approach is evaluated for its effectiveness in improving wireless power transfer in UAV applications, providing insights into practical implementation and performance optimization.

This chapter addresses techniques for extending the charging range of PT-symmetric WPT systems. It begins with an introduction to range extension methods and then explores the use of S/SLDC high-order topologies for improved performance. The chapter includes system analysis, modelling, and comparison with other topologies, focusing on negative resistance design to enhance range. Additionally, it presents flexible charging range extension methods, such as autonomous on-off keying modulation schemes, and discusses their system output characteristics and control algorithm implementation. Experimental verification supports the proposed methods, showcasing advancements in expanding the operational range of PT-symmetric WPT systems.

This chapter details advanced control strategies for wireless charging systems used in UAVs. It begins with an introduction to control challenges specific to wireless charging and then discusses model-predicted control approaches, particularly those using high-order LCC-P topologies. Key topics include system modelling, mutual inductance prediction, and controller design, supported by both simulation and experimental verification. The chapter also covers rotating-coordinate-based mutual inductance estimation, including system modelling in the dq synchronous reference frame and the αβ-to-dq transformation. This section emphasizes the importance of accurate control for efficient and reliable wireless power transfer.

This chapter introduces the principles and mechanisms behind wireless power transfer (WPT), focusing on inductive power transfer systems. It begins with the historical development of WPT and then delves into the fundamental aspects of inductive power transfer, including general configurations. The chapter provides a detailed examination of theoretical models, such as the loosely coupled transformer model, T-model, and M-model, and compares their effectiveness. It further explores compensation networks, including series and parallel types, and discusses transmission performance metrics such as output power, transfer efficiency, and their interrelationships. This comprehensive overview establishes the foundational knowledge necessary for understanding advanced WPT systems.

Chapter 7 considers structural loading and response of horizontal-axis machines, with some theoretical background and illustrative measurements from different wind turbine types. The chapter begins with a recap on the dynamics of a single degree of freedom system, leading into a discussion of multi-DOF systems and modal analysis. The cyclic loads affecting a wind turbine structure are described including wind shear, tower shadow, and rotationally sampled turbulence. The concepts of stochastic and deterministic loading are explained and the principle of aerodynamic damping illustrated. Qualitative descriptions are given of gyroscopic, centrifugal, and electromechanical loading. The phenomenon of blade edgewise stall vibration is explained, with discussion of mechanical damper solutions. The last part of the chapter draws on an early experimental campaign in which the dynamic loading on a full scale wind turbine was measured and compared with the results of software simulation. Results from the same trials also demonstrate the difference in rotor thrust loading arising from positive and negative pitch control. The chapter concludes with a brief summary of fatigue prediction methods.

This chapter is a largely non-technical overview of economic and political aspects of wind energy policy. The cost of wind energy is assessed in terms of Levelised Cost of Energy (LCoE) with equations given in full and simplified form. Using a large database historic installed costs for UK wind both on- and offshore are given, from the earliest projects to the present day. The observed trends are discussed. Operational and balancing costs are outlined, the latter reflecting the intermittency of wind power. LCoE estimates are made for a range of installed costs and output capacity factors at typical discount rates, and compared with current generation prices. The chapter considers the economics of onsite generation with the example of a private business using wind energy to offset demand; the energy displacement and export statistics are extrapolated to compare with a national scenario for 100% renewable electricity generation. The topic of ownership is introduced and examined in the context of the UK’s first community-owned windfarm. The chapter concludes with a brief review of UK renewable energy policy, which originated with legislation to protect the nuclear power industry.