The streamer inception voltage simulation method is described as implemented in the post processing of Ansys Maxwell electrostatic solver. Physical model-based streamer simulation demands tremendous simulation time and is hard to apply for real engineering cases. The streamer criteria approach described here provides a fast, accurate and easy to use method to evaluate the streamer inception voltage for gas insulation. The simulation is based on electrostatic simulation for 2D/3D models. From the electrostatic simulation results, the electric field line tracing is performed from defined starting points. Field line tracing has two methods: 1) insulation gas space 2) along the solid insulator surface. Based on the electric field value along this field line and the streamer inception criteria, the streamer inception voltage can be calculated, which is influenced by effective ionization coefficient properties of insulation gas, the streamer constant, the electric field ‐ distribution, the pressure of the insulation gas. Two industrial examples were simulated and compared with test results, the simulated and test results agreed with each other. It provides an easy accurate and fast way to calculate the streamer inception voltage which can support the design of high voltage devices in general.

The aim of this study is to present a thermal analysis of a permanent magnet synchronous machine based on finite element method. The developed model can be used to predict temperature distribution inside the studied motor during the rated operation. Electromagnetic computation is carried out with the aid of two 2D finite-element (FE) simulations on the cross-section of the PM motor. To analyse the process of heat transfer in an electrical machine, empirical correlations are used to describe the convective heat transfer from the different surfaces of the PM motor. The heat transfer coefficient is determined using dimensionless numbers and Nusselt number. After the loss calculation, the temperatures of the machine are calculated by using 3D finite element method. The results obtained by the model are compared with experimental results from testing the prototype electric motor.

The aim of this study is to present a thermal analysis of a permanent magnet synchronous machine based on the finite element method. The developed model can be used to predict temperature distribution inside the studied motor during the rated operation. Electromagnetic computation (EM) is carried out with the aid of two 2D finite‐element (FE) simulations on the cross‐section of the PM motor. To analyse the process of heat transfer (HT) in an electrical machine, empirical correlations are used to describe the convective (HT) from the different surfaces of the PM motor. The (HT) coefficient is determined using dimensionless numbers. The proposed numerical method to solve the coupled problem is based on independently and successively solving the (EM) and thermal problems and then transferring the results between the two sub‐problems. The results obtained by the model are compared with experimental results from testing the prototype electric motor.

The main objective of our task is to develop mathematical models, numerical techniques to analyse the thermal effects in electric machines, to implement the developed algorithm in multiprocessor or multi-core environments and to apply them to industrial use cases. In this study, we take into account coupled character of the electromagnetic and thermal features of the physical process. Both thermal and electromagnetic processes are considered transient, solved by means of the FEM method on independent meshes and the time-discretization is realized using time operator splitting. Two examples are presented to assess the accuracy of the developed coupled solvers and the numerical results are compared with the experimental ones, which are obtained from a prototype machine.

Passive wheel speed sensors are widely used in automotive applications where knowledge of the rotational velocity of the rotating axes and resistant to environmental impacts are required. This paper presents a general introduction to wheel speed sensor systems and the underlying physical behaviour are explained with the help of three-dimensional time-stepping finite element method. The 3D field simulations well reflect the dynamics of the magnetic field of the real problem and they provide a quantitative understanding of the output signal behaviour concerning model parameter variations. The sensor geometry is analyzed in detail, featuring a study of the influence of the main parameters. As an outcome of parameter analysis, it was possible to determine the influence of the sensor parameters on the output signal of the sensor. In addition, this study aims to advance the understanding of the physical behaviour of passive wheel speed sensors by three-dimensional nonlinear finite element analysis, which is missing from the literature.

Transformer noise is a significant contribution to unwanted ambient noise, especially in the vicinity of the electrical transmission facility. It is therefore very important to get to know the mechanism of noise generation of the distribution transformer. As outcomes of this work, a finite element based multiphysics model is presented which provides a convenient and efficient toolchain for simulating the transformer sound emission mechanism. Finally, the operation of modelling chain is presented on a 200kVA distribution transformer simulation.

A major problem in switched reluctance motor is torque ripple, which causes undesirable acoustic noise and vibration. This work focuses on reducing the undesirable torque ripple in 6/4-pole three-phase switched reluctance motor by geometry modification and using control technique. The proposed method combined the specially skewed rotor pole shape with instantaneous torque control with sinusoidal torque sharing function. The results of geometry modification are analysed through the three-dimensional finite element simulation to determine the appropriate skewing angle. The drive performances of conventional and modified motor are compared through the simulations. The effectiveness of the proposed method is also demonstrated and verified by the simulations.

The paper presents a brief review of the movement modelling methods of electric machines and the two most common used torque calculation techniques. After the classification of single-layer moving band methods, a low computation cost and an easily realisable new variant of this movement modelling technique is proposed. To study the accuracy of proposed moving band technique equipped with Arkkio's method and Maxwell's stress tensor method for torque calculation an international benchmark problem used. Further, to check the applicability, the proposed method has been used to analyse a three-phase switched reluctance motor. The results of proposed method have been compared to analytical and numerical results.

This research presents a field-circuit coupled parallel finite element model of a switched reluctance motor embedded in a simple closed loop control system. The parallel numerical model is based on the Schur-complement method coupled with an iterative solver. The used control system is the rotor position based control, which is applied to the FEM model. The results and parallel performance of the voltage driven finite element model are compared with the results from the current driven model. Moreover, the results of the start-up of the loaded motor show why the model accuracy is important in the control loop.

Purpose– The purpose of this paper is to present the importance of model accuracy in closed loop control by the help of parallel finite element model of a voltage-fed solenoid with iron core.Design/methodology/approach– The axisymmetric formulation of the domain decomposition-based circuit-coupled finite element method (FEM) is embedded in a closed loop control system. The control parameters for the proportional-integral (PI) controller were estimated using the step response of the analytical, static and dynamic model of the solenoid. The controller measures the error of the output of the model after each time step and controls the applied voltage to reach the steady state as fast as possible.Findings– The results of the closed loop system simulation show why the model accuracy is important in the stage of the controller design. The FEM offers higher accuracy that the analytic model attained with magnetic circuit theory, because the inductance and resistance variation already take into account in the numerical calculation. Furthermore, parallel FEM incorporating domain decomposition to reduce the increased computation time.Originality/value– A closed loop control with PI controllers is applied for a voltage driven finite element model. The high computation time of the numerical model in the control loop is decreased by the finite element tearing and interconnecting method with direct and iterative solver.

This paper presents an axisymmetric formulation of the circuit-coupled finite element method embedded in closed loop control system. The controller checks the current of the coil of the magnetic system after each time step and controls the applied voltage to reach the steady state faster. The results of the voltage driven finite element model are compared with the results from the analytical model. The control parameters for the proportional-integral-derivative controller were estimated using the step response of the system. Furthermore, the results of the closed loop system simulation show why the model accuracy is important in the controller design.

The analysis and design of electromechanical devices involve the solution of large sparse linear systems, and require therefore high performance algorithms. In this paper, the primal Domain Decomposition Method (DDM) with parallel forward-backward and with parallel Preconditioned Conjugate Gradient (PCG) solvers are introduced in two-dimensional parallel time-stepping finite element formulation to analyze rotating machine considering the electromagnetic field, external circuit and rotor movement. The proposed parallel direct and the iterative solver with two preconditioners are analyzed concerning its computational efficiency and number of iterations of the solver with different preconditioners. Simulation results of a rotating machine is also presented.