Improving the Reliability of Tidal Turbine Generator Systems

Among different ways of harnessing tidal energy, tidal stream turbines are gaining popularity over traditional tidal dams. This is owing to the lower capital cost, and potentially lower ecological impact of tidal turbines. However, compared to more developed sources of energy, tidal energy remains expensive, which impedes its large-scale...

Investigation into Multi-Phase Armature Windings for High-Temperature Superconducting Wind Turbine Generators

High-Temperature superconducting (HTS) generators are being considered as a competitive candidate in large direct-drive (DD) wind turbines because of their features of being lightweight and compact. Normally a large air gap is inevitable in partially HTS generators, sacrificing the torque producing capability. In this paper, multi-phase...

Performance of Multi-Layer and Stator-Shifting Fractional-Slot Concentrated Windings for Superconducting Wind Turbine Generators under Normal and Short-Circuit Operation Conditions

High temperature superconducting (HTS) generators are being considered for large offshore direct-drive (DD) wind turbines as they are expected to be lightweight and compact. However, short circuit torques of an HTS generator with integral-slot distributed windings (ISDWs) are too high for wind turbine constructions, mainly due to the large...

A New Rotor Structure for High Speed Flywheel Permanent Magnet Synchronous Machine

This paper presents a new rotor design with assembled permeable retaining sleeve (APRS) to improve performances of a high speed permanent magnet synchronous machine (PMSM). The APRS consists of equal number of permeable and nonmagnetic parts, which are alternately arranged and assembled together circumferentially via keyways. Electromagnetic and...

Calculation of PWM-induced rotor-can losses in flooded generators

Improving availability of tidal turbines has been identified as a key area to lower the levelized cost of energy from tides. One of the approaches suggested to achieve high reliability is to use a flooded permanent magnet (PM) generator. Flooded PM generators are designed to operate with a seawater filled stator-rotor gap in the generator. Using...

Comparing different materials for rotor-can in flooded generators

Flooded Generators have been proposed as a possible solution to eliminate the risks due to the seal failure, and improve cooling in tidal stream turbine generators. In a flooded generator, the stator-rotor gap is filled with the seawater; this poses a serious corrosion risk to the material inside the generator. For this reason, a can or a...

Fast rotor loss calculations in fractional-slot permanent magnet machines

Permanent magnet machines with fractional slot windings are popular because of their shorter end windings, low cost and ease of manufacturing. On the other hand, fractional slot machines have higher eddy current losses in the rotor magnets and sleeve. An accurate calculation of these losses usually involves a time-stepped finite-element analysis...

Comparison of Nested-Loop Rotors in Brushless Doubly-Fed Induction Machines

The brushless doubly-fed induction machine (DFIM) has great potential as a variable-speed generator for wind turbine applications. This special machine has a richer space-harmonic spectrum due to its special nested-loop rotor construction compared with conventional induction machines. It may result in higher iron losses, higher torque ripple and...

Finite Element Analysis and Experimental Validation of Eddy Current Losses in Permanent Magnet Machines with Fractional-Slot Concentrated Windings

Permanent-magnet machines with fractional slot concentrated windings are easy to manufacture. Their popularity therefore is steadily increasing. Without a proper design, however, the induced eddy-current losses in the solid rotor get rather high. The modeling and the prediction of eddy-current losses for these machines are thus very important...

Modeling of Exterior Rotor Permanent Magnet Machines with Concentrated Windings

In this thesis modeling, analysis, design and measurement of exterior rotor permanent magnet (PM) machines with concentrated windings are dealt with. Special attention is paid to slotting effect. The PM machine is integrated in flywheel and used for small-scale ship application. Analytical model and automated nonlinear transient finite-element...

Influence of stator slotting on the performance of permanent-magnet machines with concentrated windings

The use of slotted stator permanent-magnet machines with concentrated windings is increasing in industry. In this paper, the effect of the slot opening on flux linkage, internal voltage, mean torque, rotor eddy current loss and stator iron losses is evaluated. This gives new insight into the influence of slotting on the performance of machines...

Validation of Eddy Current Loss Models for Permanent Magnet Machines with Concentrated Windings

The Development of Range Extender Generator By Evaluating The Eddy Current Losses and End Effect Using FE Method

Peec-Power B.V. is developing high power range extender for hybrid electric vehicles. The first generator designs for range extender have been built and tested in the laboratory. The prototype generators use a permanent magnets with a radial flux type. These prototypes use two kinds of fractional-slot concentrated winding. The slot pole...

Eddy Current Losses Calculation in Rotor Back Iron and Magnet for Concentrated Winding Permanent Magnet Generator

The concentrated winding is proposed to replace the distributed winding due to the advantages in a manufacturing process. It is easily wounded by a machine in the former and the impregmentation process that can be carried out separately for each individual coil. These advantages can lead to the automation process in winding processes, reduced...