Wind turbines are subjected to asymmetric loads and fatigue with subsequent increases in their dimension and capacity, leading to a reduction in their lifetime. To address this problem, the individual pitch control (IPC) technique is quite familiar in the control of wind turbines. IPC is used to reduce the tilt and yaw moments, simultaneously alleviating the turbine blade-root bending moments (BRBMs). This study discusses the performance of model predictive control (MPC), H-infinity ($H_{\infty }$), and proportional and integral (PI)-based IPC strategies integrated with collective pitch control. The performance of the reported controllers has been validated using the National Renewable Energy Laboratory (NREL) 5 MW full nonlinear reference wind turbine. Simulation studies are conducted at varying wind speeds and turbulent intensities as per international electrotechnical commission (IEC) norms. Comparative results in the time and frequency domains indicate that the $H_{\infty }$ based IPC achieves enhanced control performance in terms of reduction in BRBMs and damage equivalent load compared to MPC and PI-based control strategies.

Based on the dimensions and thresholds of power and power density of a commercial shock absorber in the Korando car (an SUV branch), a single-phase 8 slot - 8 pole tubular permanent magnet machine was designed and fabricated. The main focus of this study was on the increase of output power in a given space and reduction of the volume. This was successfully solved using a novel structure for a permanent magnet and considering a number of slot-pole combinations. Furthermore, a multi-objective optimization was performed to find the trade-off between various objectives. The experimental results reveal that the proposed machine could possibly regenerate a maximum of 339.95 W and an average of 96.67 W in terms of its output power. Considering the active volume, which includes a permanent magnet, iron core, pure copper, and an electromagnetic air gap, the estimated maximum and average power density were 0.311 and 0.087 W/cm $^3$ , respectively. Despite these satisfactory results, one of the major drawbacks to exploiting this machine is its high electromagnetic force, which causes negative effects on safety and driving comfort. With the aim to commercialize the proposed device, further work will be concentrated on the reduction of electromagnetic force and on performance of the road tests.

This paper deals with the design of an electromagnetic energy harvesting generator for the suspension system of a sport utility vehicle. The proposed generator is composed of a single coreless type permanent magnet layer, which increases flux density across the coil windings and eliminates flux leakage by using the Halbach PM array, thus improving the machine’s performance, including flux linkage and output power. The goal of the system is to regenerate energy from the kinetic energy of the suspension system of the sport utility vehicle. The proposed generator physically combines electrical and mechanical components, in which permanent magnets, coil windings, and back iron are attached to the body of the shock absorber. The design’s performance was investigated using the finite element method (FEM) and validated by comparison with experimental data.

This paper proposesthe design process and performance of an Urban Water-pipeline Energy Harvester (UWEH) System. The UWEH system design is broadly divided into two parts, namely, the electromagnetic and mechanical subsections modeling. The electromagnetic modeling includes the selection, design, prototyping and performance testing of a 65-kW permanent magnet synchronous generator (PMSG) which runs at the rated speed of 500 rpm. The mechanical modeling includes the installation, bearing selection, propeller system integration and waterproof sealing mechanism of the whole UWEH system for the field test. Detailed information on practical implementation is highlighted. Finally, based on the lessons learned from the problem associated with the mechanical subsection, a bearing-less buoyant rotor mechanism is proposed explaining its airgap control mechanism.

In this paper, a modification of the dual-segment permanent magnet (PM) Halbach array is investigated to improve the performance of the tubular linear machine, in terms of flux density and output power. Instead of a classical Halbach array with only radial and axial PMs, the proposed model involves the insertion of mig-magnets, which have a magnetized angle shifted from the reference magnetized angles of axial and radial PMs. This structure leads to the elimination of flux leakage and the concentration of flux linkage in middle of the coil; therefore, the output power is increased by 13.2%.