A novel method to optimize permanent magnet assisted synchronous reluctance machines

This paper presents the characteristics of permanent magnets in a synchronous reluctance machine by employing analytical and finite element methods. Four possible designs are studied and their characteristics are compared against a base synchronous reluctance machine with linear barriers to reveal machine characteristics. Then, the paper proposes a novel optimization topology to optimize permanent magnet synchronous reluctance machine as a single object for better machine performance. An explicit investigation is conducted to reveal the operational behavior of the machine such as torque, power factor and torque ripples with various machine parameters and compares them with the base design. The study reveals that permanent magnet synchronous reluctance machine can be optimized to have significantly high-power factor and torque with acceptable torque ripples

Performance comparison of various probability gate assisted binary lightning search algorithm

Recently, many new nature-inspired optimization algorithms have been introduced to further enhance the computational intelligence optimization algorithms. Among them, lightning search algorithm (LSA) is a recent heuristic optimization method for resolving continuous problems. It mimics the natural phenomenon of lightning to find out the global optimal solution around the search space. In this paper, a suitable technique to formulate binary version of lightning search algorithm (BLSA) is presented. Three common probability transfer functions, namely, logistic sigmoid, tangent hyperbolic sigmoid and quantum bit rotating gate are investigated to be utilized in the original LSA. The performances of three transfer functions based BLSA is evaluated using various standard functions with different features and the results are compared with other four famous heuristic optimization techniques. The comparative study clearly reveals that tangent hyperbolic transfer function is the most suitable function that can be utilized in the binary version of LSA

HV substation earthing design for mines

High Voltage (HV) substation forms important assets for the mining industries. The existences of these substations necessitate earthing design to ensure safety compliance to the mine regulations. The HV system within the mines is consisted of multiple substations which are connected throughout and underground cable. These substations provide the load with the required electrical power to perform its tasks. This paper endeavours to provide information in regards to the different types of connections between the load and the substations (TT, TN and IT Systems). Furthermore, the earthing arrangements under different connection were assessed. A case study is addressed to show the different earthing arrangements under different connection systems

Soil resistivity data computations : single and two-layer soil resistivity structure and its implication on earthing design

Performing High Voltage (HV) tasks with a multi craft work force create a special set of safety circumstances. This paper aims to present vital information relating to when it is acceptable to use a single or a two-layer soil structure. Also it discusses the implication of the high voltage infrastructure on the earth grid and the safety of this implication under a single or a two-layer soil structure. A multiple case study is investigated to show the importance of using the right soil resistivity structure during the earthing system design

Soil resistivity structure and its implication on the pole grid resistance for transmission lines

High Voltage (HV) transmission lines are widely spread around residential places. They take all forms of shapes: concrete, steel, and timber poles. Earth grid always form part of the HV transmission structure, whereat soil resistivity value is one of the main inputs when it comes to determining the earth grid requirements. In this paper, the soil structure and its implication on the electrode resistance of HV transmission poles will be explored. In Addition, this paper will present simulation for various soil structures using IEEE and Australian standards to verify the computation with CDEGS software. Furthermore, the split factor behavior under different soil resistivity structure will be presented using CDEGS simulations

How to design an effective earthing system to ensure the safety of the people

Performing High Voltage (HV) maintenance with a multicraft work force creates a special set of safety circumstances. The safety of people including workers will be discussed in this paper. In Addition, this paper will present an effective approach to design an earthing system. This approach explains the theoretical background necessary to perform the calculation of the required safety voltages. Finally, this paper provides a verification of the proposed approach via simulation with Current Distribution, Electromagnetic Fields, Grounding and Soil Structure Analysis CDEGS software

Sensorless control of brushless DC motors using virtual back EMF mapping projection

This paper presents a new approach for sensorless control of brushless dc motors (BLDCM). A linear back emf line is constructed reflecting the rotor displacement angles, from which the commutation instances corresponding to 30° degrees are computed. The approach increases the signal to noise ratio and improves the performance as compared with zero crossing detection point (ZCP) method. Simulation results are presented for a DC brushless drive at various load conditions. It is shown that the virtual effect sensors (VHE) signals follow the same interval as physical Hall effect (PHE) signals

Conversion of a switched reluctance motor to operate as a generator for wind power applications

Climate change effect become number one concern in many countries due to the effect that will have on human life. Renewable energy found to be one of the most effective ways to overcome this problem, wind energy is part of the renewable and one of the most growing areas in this field. In this paper the definition of switched reluctance generator and the principal of operation will be discussed, the excitation cycle and its relation to the switching parameters, methods on the switching phenomena will be discussed, low speed circuit and high speed circuit will be explained, output power of the SRM

Design and performance of interior permanent magnet motors with saturating magnetic bridge

Permanent magnet (PM) machines are capable of high efficiency, high power density and extremely wide power operating range. With these characteristics there has been considerable interest in applying them for motion control and robotic applications. Due to their high efficiency, PM machines are ideal general drives in many consumer goods to reduce energy consumption and improve performance. This paper outlines design, fabrication and simulation of interior permanent magnet machines (IPM) with and without saturating magnetic bridge. Based on the study, an IPM is fabricated, tested and performance compared with an equivalent induction motor. The design details of the fabricated IPM machine are also given

Design of synchronous torque couplers

This paper presents the design, analysis and development of permanent magnet (PM) torque couplers. These couplers employ rare-earth magnets. Based on finite element analysis and earlier analytical works both concentric and face-type synchronous type couplers have been designed and fabricated. The experimental performance has good correlation with finite element calculations