Double Armature Research Articles

Double Armature HTS Bulk Synchronous Machine for Contra-Rotating Turbine Generator

Many high-temperature superconducting (HTS) rotors of the radial flux type mainly use the magnetic field from single sided surface of the field pole. However, field poles using HTS bulk have the advantage of capturing high magnetic fields on both sides of the field poles, which can be effectively used to generate electricity. Therefore, we have developed a double armature structure in which a field stator is sandwiched between both the inner and outer armature rotors of the HTS synchronous generator. Due to the high magnetic field captured by the HTS bulk, it is also possible to directly join a counter-rotating turbine. In this paper, we designed the developed model and performed electromagnetic field analysis. The analytical speed was calculated at a low speed depending on the design of the 500kW reverse rotation turbine. Using the HTS bulk as the boundary pole, the torque consistency with the input mechanical torque of the turbine was confirmed, and it was obtained from the compatibility analysis with the 500kW class tidal current power generation. We also analyzed the model with the smallest torque ripple from multiple models with different HTS bulk placements and found the model with the best placement.

Design and analysis of semi-closed stator core transverse flux permanent magnet generator

Purpose The purpose of this paper is to modernize the generator system of wind turbine concept that not only improves the efficiency and power density but also reduces the system cost making design simpler and less expensive, especially in large-scale production. Design/methodology/approach This paper presents a new permanent magnet transverse flux generator (PMTFG) for wind energy production. The key feature of its composition is the double armature coil in a semi-closed stator core. The main structural difference of the presented design is the use of double coil in the same space of semi-closed stator core and reduced number of stator pole pairs and rotor magnets from 12/24 to 10/20. 3D simulations are performed using finite element analysis (FEA) to measure induced voltage and magnetic field distribution at no load. The FEA is performed to quantify the change in flux linkage, induced voltage and output power as a function of different speeds and load current. Findings Results show that PMTFG with double coil configuration has improved electromagnetic performance in terms of flux linkage, induced voltage, output power and efficiency. The power density of 10/20 PMTFG with the double coil is 0.0524 KW/Kg, about an 18% increase compared to the conventional design. Research limitations/implications The proposed PMTFG is highly recommended for direct drive applications such as wind power. Originality/value Four models are simulated by FEA with single and double coil configuration, and load analysis is performed on all simulated models. Finally, results are compared with conventional PMTFG.

Double armature HTS bulk synchronous machine

In many high-temperature superconducting (HTS) rotating machines of radial flux type, the magnetic field from one side surface of the field pole is employed facing the armature winding. However, both side surfaces of the field pole can be effectively utilised to face the armature windings. Thus, we have applied the double armature structure in which both inner and outer armature rotors sandwiched the field pole stator in the HTS synchronous generator. We introduce the first step design and the electromagnetic study of the double armature synchronous machine for tidal current power generation. The double armatures with copper winding were adopted with a field pole composed of the HTS bulks. The power and the torque density were calculated with a low speed that depends on a 500 kW contra-rotating turbine design. In this paper, we comparatively studied three electromagnetic designs in which (1) a permanent magnet was used for the field pole, (2) the HTS bulk was employed as the field pole and (3) the field pole HTS bulk was arranged at an angle in the x-y plane, reducing torque ripple due to torque consistency and tilting of the HTS bulk plate. A generator model consistent with the input mechanical torque of the turbine was obtained from the analysis of compatibility with the 500 kW class tidal current power generation.

Double Armature Partitioned Stator Switched Flux PM Machine for Electric Vehicle Applications

This paper investigates the performance of a partitioned stator switched flux PM machine that has double armature windings. The machine design is dedicated for electric vehicle applications. The modular structure, and the operation principles have been explained. Also, the design and optimization procedure for the machine including the rotor and stator number of poles and optimum parameters of the design have been clarified. The performance of the machine is compared with the conventional partitioned stator machine with a cylindrical inner stator and the salient inner stator machines, and the Prius IPM machine. The partitioned stator machines have the same main parameters which are globally optimized for optimum average torque. The comparison is based on the electromagnetic performance in the open-circuit and on-load analysis. The 2D finite element results show the superior performance of the double armature portioned stator machine based on the highest average torque, the minimum cogging torque, and best torque-current density and torque per PM volume characteristics.

INVESTIGATION OF LINEAR PULSE ELECTROMECHANICAL CONVERTER OF INDUCTION TYPE WITH DOUBLE ARMATURE INTENDED FOR DESTROYING INFORMATION ON SSD STORAGE DEVICE

Purpose. The goal of the paper is to determine the influence of the linear pulse electromechanical converter (LPEC) parameters with a double armature on its electrical, power and temperature indices and experimental verification of the proposed design for an information destruction device in a flat SSD storage device. Methodology. Using the mathematical model that takes into account interrelated electrical, magnetic, thermal and mechanical processes, the influence of geometric parameters on the electrodynamic characteristics and the indices of the induction type LPEC with a double armature spanning the inductor from opposite sides is investigated. Results. It is shown that the currents in the inductor and armature change in accordance with the oscillation-damping law practically in antiphase. The maximum value of the current density in the inductor is 215.8 A/mm2, and in each of the identical parts of the double armature it is 299.7 A/mm2. The maximum value of electrodynamic forces (EDF) acting in opposite directions on the front and rear of the double armature is 11.99 kN, and the value of the EDF pulse is 4.59 N∙s. Originality. It is established that with axial removal of the rear part of the armature from the inductor, the maximum current densities in the inductor decrease, in the front part of the armature increase, and in the rear part of the armature decrease. The maximum value and the pulse of the EDF between the armature parts decrease. With an increase in the number of turns in the inductor and a decrease in the thickness of the copper bus, all the basic indicators of the LPEC increase. With an increase in the number of turns of the inductor from 26 to 56, the maximum EDF value acting between the parts of the armature increases almost 3 times, and the magnitude of the EDF pulse is 3.3 times. With an increase in the width of the copper bus and the width of the inductor, the main indicators of the LPEC decrease. With an increase in the width of the inductor from 10 mm to 20 mm, the maximum EDF between the armature parts decreases by 1.3 times, and the value of the EDF pulse decreases by 1.2 times. Practical value. Based on the conducted studies, an induction-type LPEC model with a double armature was designed and tested experimentally, designed to destroy information located on a solid-state digital SSD storage device.

Radial and axial flux superconducting motors in a levitating rotor configuration

The capability of superconducting blocks to be partially magnetized allows both bearing and powering functions in a conventional stator and superconducting rotor configuration. This levitating rotor concept is investigated by means of the basic parameters: torque, levitation and centering forces in two motors with radial and axial excitation respectively. We report on the design and behavior of a high speed motor with a cylindrical HTSC rotor excited by a conventional four poles four phases armature generating a radial field. We also report on a second motor with a disk shaped HTSC rotor excited by a conventional, four poles three phases, double armature which generates an axial field in the gap. Torque, power and centering and levitating forces measurements are also provided.

Static and Dynamic Characteristics of a Double Armature DC Linear Motor

A brushless and slotless dc linear motor employing a movable set of neodymium-boron-iron type magnets is discussed in this paper. The motor can be used as a linear stepping motor as well, due to its unique topology. The flux density at specific points and the static force along the travel length of the motor were measured. A 3D finite element analysis of the flux distribution and of the static force were carried out. The dynamic characteristics such as velocity, output power and efficiency for various conditions were measured.

CURRENT COMMUTATION ANALYSIS IN SELF-CONTROLLED DOUBLE STATOR SYNCHRONOUS MACHINES TAKING INTO ACCOUNT SATURATION EFFECT

In the field of high power drives, the double armature synchronous machines constitute an advantageous choice compared to classical synchronous machines, because of the relatively low torque ripple produced. This paper proposes an analytical model of the current commutation and its influence on pulsating torque, in converter fed Double Stator Synchronous Machines (DSSM), taking into account the magnetic saturation with cross-magnetizing effect. A comparative study, between the linear model (saturation neglected) and the proposed one, is developed with the aim of estimating the influence of the magnetic non-linearity on these two phenomena.