Electric power industry is extensively using gas‐insulated systems for the transmission and distribution of electrical energy. In high‐voltage technology, the gas insulation is dominated by Sulphur‐hexafluoride (SF ₆ ) since the early 60th. It is a greenhouse gas and has long atmospheric lifetime. This paper proposes comparatively more environmental friendly R410 gas as an alternative to SF ₆ for high‐voltage applications. To validate the performance and theoretical concepts, it has been analysed experimentally. Buffer gases air and carbon dioxide were mixed with the base gas R410A to reduce the liquification temperature and global warming potential. Dielectric strength of R410A was tested for DC as well as AC voltage, results were compared with that of SF ₆ and other alternatives available in literature, and the results were comparable. Insulation self‐recoverability test of R410A was performed and the synergistic effect of the mixed gases was calculated. Consequently, this work has discovered that R410A is the suitable alternative to SF ₆ for high‐voltage applications.

This article proposes a segmented and double stator flux switching linear hybrid excited machine (SDSFSLHEM). To reduce the machine’s iron loss and overall cost, the proposed SDSFSLHEM utilizes a segmented stator. At both ends of the mover, assistant teeth compensate for the unbalance in the three-phase flux, which is a common problem in linear machines. Field excitation (FE) is used, which adds flux regulation capability to the proposed machine and allows it to operate at a wide range of speeds. A magnetic equivalent model (MEM) is used to find the best coil combination and no-load flux linkage, to reduce computational time. The leading design parameters of the machine are globally optimized by multiobjective genetic global optimization, while keeping the slot area, electric, and magnetic loadings constant. The optimization improved peak-to-peak flux linkage by 12%, thrust force by 34.7%, thrust ripples by 17.97%, and detent force by 10.07%. Compared to the flux switching permanent magnet (PM) machine proposed in the literature, the proposed machine reduces the volume of the PM by 39.18% and provides 31.2% higher thrust force and thrust density.

This article presents linear oscillating actuator (LOA) which generates bidirectional linear thrust force. Design topology of the proposed LOA contains an outer mover and an inner stator design. Two axially magnetized and tubular-shaped permanent magnets (PMs) are mounted on the mover. Due to the higher magnetic flux density of axially magnetized PMs in a specific direction, it generates higher thrust force than radially magnetized PMs. The proposed LOA operates on single-phase alternating source. All the design specifications of the LOA are optimized through finite element method (FEM) and optimum values of the design parameters are obtained. Output parameters such as the stroke length and thrust force are analyzed for multiple magnitudes of the input parameters such as current using FEM. Additionally, other parameters like back emf, coil current and winding resistance are analyzed at resonance. Effect of motor constant is investigated toward both directions of the force, which shows identical replication. Output parameters of the LOA are compared with already designed topologies of the LOA for refrigeration system. Proposed LOA demonstrates promising improvements in terms of motor constant and thrust force compared to the volume of the LOA. Moreover, proposed LOA is comparatively convenient to fabricate as well.

This paper proposes double sided complementary modular field excited flux switching linear machine (FEFSLM). FEFSLM offers the low cost, variable flux capability for a wide speed range, a compact and robust stator which is suitable for the long stroke application. Compared to other linear machines, complementary modular design has more sinusoidal and symmetrical flux linkage and lower detent force. Initially, the topology and machine working principle is thoroughly discussed. To maximize the thrust force of the machine and optimize the geometric parameters, built-in genetic algorithm (GA) of JMAG ver. 20 is utilized. Furthermore, the modular design incorporates the concept of fault-tolerant capabilities to provide the required decoupling between phases. 2D finite element analysis (FEA) is used to analyze the machine performance. Comparatively the optimized design exhibits higher thrust force, lower thrust force ripples and higher efficiency than the initial design.

In this paper two double-sided Field Excited Linear Flux Switching Machines (FELFSM) are analyzed. Both machines share the same robust and compact stator structure with a modular mover design having different winding configurations namely concentrated and toroidal. The proposed machines have a low-cost owing to the lack of rare earth materials, a high fault-tolerant capability due to the modular construction of the mover, and flux controllability due to field current variation. The initial designs are optimized through a genetic algorithm using JMAG software ver. 20.1. to maximize the thrust force and minimize thrust force ripples ratio. After optimization, the average thrust force in Machine I and Machine II is increased by 31.96% and 32.31%, respectively. Additionally, a mathematical model is developed to compute electromagnetic thrust force and fault-tolerant capability. The electromagnetic performance of both machines are compared through 2D FEA. Both analytical and FEA-based designs are verified through experimental validation on the developed prototype. Finally, a coupled electromagnetic-thermal study is carried out, with the temperature of the prototype being visualized experimentally using a Fluke VT04 IR thermometer.