In situ measurements of static characteristics for an ad-hoc silicon-on-insulator (SOI) device represent an important method for SOI technologies characterisation. The Separation by IMplanted OXygen (SIMOX) technique is based on oxygen ions implantation into Si-film. After annealing, an increased doping concentration was reported, because of the residual oxygen clusters within the film, giving rise to oxygen thermal donors. Therefore this study offers an original algorithm for doping concentration estimation in these SOI films. A specific device used for in situ electrical characterisation of SOI wafers is the pseudo-metal oxide semiconductor (MOS) transistor. In this study, the doping concentrations extraction is based on graphical solution of a non-linear equation and third-order derivative zeroing of the measured static characteristics. In this scope, experimental curves I _D–V _G, in inversion and accumulation were experimentally measured for a pseudo-MOS transistor made in SIMOX technology. In this situation, the threshold and flat-band voltage are extracted, free of classical conventions. The extracted doping concentration in film is roughly 5.8 × 10¹⁵ cm^{− 3}; also the conductivity is changed from p to n in film, as the literature predicted.

Modal analysis is widely approached in the classic theory of power systems modelling. This technique is also applied to model multiconductor transmission lines and their self and mutual electrical parameters. However, this methodology has some particularities and inaccuracies for specific applications, which are not clearly described in the technical literature. This study provides a brief review on modal decoupling applied in transmission line digital models and thereafter a novel and simplified computational routine is proposed to overcome the possible errors embedded by the modal decoupling in the simulation/modelling computational algorithm.

A novel combination of genetic algorithms (GAs) and the charge simulation method (CSM) is proposed for enhancing the computation precision of electric fields associated with plate-type electrostatic separators; a new recycling technology of electrical and electronics waste. An algorithm is developed to, automatically, arrive at optimal arrangement of the simulating charges and their locations in order to eliminate dependency on user judgment and experience. Accurate results for electric field computation, compared with earlier published techniques, are realised for several design parameters of the separator. Experiments carried out for determination of detachment fields of small metallic particles (steel spheres of radius 0.501 mm) confirmed validity of the numerical simulation. The present work shows that the coupled GA–CSM algorithm can be an efficient and flexible design tool for accurate field computation of electrostatic separation equipment.

One of the vital causes of the failure of oil transformers is considered as the creepage discharge propagation on pressboard. The authors performed an experimental investigation under an AC step test voltage to analyse the effects of the structure, distance and gluing direction of pressboard on creepage propagation. Flat, ribbed and grooved test specimens were prepared. Further, breakdown experiments were conducted for two gluing directions, parallel and vertical with respect to the electric field. For parallel gluing, the average breakdown voltage (V _BD) of the ribbed and grooved types was 1.2–1.33 times that of the flat type. For vertical gluing, the V _BD of the flat type was 1.28–1.66 times that of the same type with parallel gluing, whereas the values for the ribbed and grooved types were 1.02–1.11 times the corresponding values for parallel gluing. The rib height and groove depth do not seem to contribute greatly to the breakdown strength because most of the flashover propagation appeared not on the pressboard's surface but at the glued interface. The results of this preliminary investigation may be useful for improving the dielectric creepage strength of solid insulation systems using pressboard as radial spacers, and high-voltage winding lead support parts.

Transmission-line modelling (TLM) is a valuable technique for numerical simulation of electromagnetic fields. Recently, investigations have been successfully carried out into the use of the TLM approach on unstructured meshes However, as the local characteristics of mesh geometry will clearly make an impact upon the fidelity of simulations, it is necessary to examine suitable techniques for mesh optimisation. Three different methods have been investigated here to find optimal meshes for subsequent TLM simulations: the centroidal Voronoi Tessellation method, the optimal Delaunay triangulation method and a spring relaxation method. These different techniques are assessed in terms of maximum efficiency of the subsequent TLM simulations and the computational cost that is incurred to identify them. Several different canonical examples of mesh are considered to determine the generality of the conclusions drawn.

A follow-up control system is designed to fulfil the fatigue test experiment of fighter empennage. To measure the distortion of empennage, a cost-effective simple rapid measurement method is put forward to permit precise pose measurement on the basis of string sensors. Two sets of string sensor measurement systems are mounted on the base and the vibration table, respectively. The joint coordinates of the measure system composed of six string sensors are determined by a coordinate measurement machine (CMM). Using the forward kinematics, inverse kinematics of Stewart table and quaternion, the string sensor measurement system gets the pose of empennage after the high-frequency component arising from vibration table is filtered by a low-pass filter. Compared with the computation data obtained from CMM, it is demonstrated that the measurement method on pose measurement by string sensor is valid and convenient. All two string sensor measurement systems can run effectively in the fatigue test experiment of fighter empennage.

This study deals with the problem of controlling a class of uncertain non-linear systems in the presence of external disturbances. To achieve this goal, a novel optimal Type-2 fuzzy proportional integral derivative (OT2FPID) controller is introduced. In the proposed controller, a novel heuristic algorithm namely particle swarm optimisation with random inertia weight (RNW–PSO) is employed. To achieve an optimal performance, the parameters of the proposed controller as well as the input and output membership functions are optimised simultaneously by RNW–PSO. To evaluate the performance of the proposed controller, the results are compared with those obtained by optimal H _∞ adaptive proportional integral derivative controller, which is the latest research in the problem in hand. Simulation results show the effectiveness of the OT2FPID controller.

There have been many applications of fibre Bragg grating (FBG) in temperature measurements; however, there are no studies concerned with their application, uncertainty and repeatability as temperature sensor in the electric power industry. This study describes the research, construction, calibration and operation of an FBG-based temperature system performing a continuous monitoring of temperature inside a fully operational and connected-to-the-grid hydroelectric generator. The FBGs were calibrated for quantification of parameters such as uncertainty, sensitivity, linearity and error. The plot of calibrating temperature against measured temperature presented a one-to-one fitting accuracy to the third decimal place, uncertainty errors smaller than 1°C and a correlation coefficient R ² = 0.99996, demonstrating good linearity and accuracy of FBG sensors for temperature measurements. After being deployed for 2.5 years, the system has proved itself to be capable of reliably and accurately measuring and monitoring temperatures inside the generator, even taking into consideration the harsh environment. Results showed that the optical system provides a better electromagnetic interference immunity when compared with conventional temperature sensors. With this system in operation, a huge amount of installation and maintenance costs could be avoided with the replacement of many kilometres of electric wires by a few optical cables.

The design and development of a novel six-axis micropositioning stage are presented in this study. Based on Stewart's theory, negative Poisson's ratio is adopted for the design of flexure hinges for this stage. The stage consists of a top hexagonal plate, a bottom hexagonal plate and six trapezoidal amplifiers. The flexure hinge in the inner part of the amplifier has a symmetrical double layer, and that in the outer part of the amplifier has an unsymmetrical single layer. The deformation and amplification are calculated in a numerical simulation with the finite element method. An experiment for measuring the displacement of the stage is carried out. In the experiments, each amplifier is driven by a piezoelectric transducer, and the displacements are measured with a laser displacement sensor then recorded for comparison of the single-axis amplifier with the six-axis stage. The results show that the amplification of the displacement of a single-axis amplifier is about 15. Also, the simulation and experimental results for the six-axis stage show all errors of motion to be <3%. It is obvious that the novel six-axis stage possesses the characteristics of high amplification and minimisation, as well as being low cost.