Permanent Magnet Wind Generator Research Articles

Optimal Design of a Direct-Driven PM Wind Generator Aimed at Maximum AEP using Coupled FEA and Parallel Computing GA

Optimal design of the direct-driven Permanent Magnet(PM) wind generator, combined with F.E.A(Finite Element Analysis) and Genetic Algorithm(GA), has been performed to maximize the Annual Energy Production(AEP) over the entire wind speed characterized by the statistical model of wind speed distribution. Particularly, the proposed parallel computing via internet web service has contributed to reducing excessive computing times for optimization.

Loss and Rating Considerations of a Wind Energy Conversion System with Reactive Compensation by Magnetic Energy Recovery Switch (MERS)

SummaryElectrical conversion system for permanent magnet wind generators is challenging due to the large rating of power semiconductor devices needed and the associated costs and losses. This motivates the search for new configurations improving these relationships. Additionally, due to the large inductance present in the generator (synchronous reactance), voltage drops results with resistive load and the generator output power is limited. Traditionally, a conventional active rectifier is used, with a 3-level type illustrated in Fig. 1a. The main challenges with this solution are the costs and also increased losses resulting from high speed switching and filter operation.A solution utilizing an active series compensation device combined with a diode bridge is investigated in this paper as shown in Fig. 1b. The series compensator supplies only reactive power with a resulting good generator utilization. This also means that the VA capability of the active semiconductor part can be reduced compared to an active rectifier since the active rectifier also needs to supply the full active power.The use of an active series compensator called Magnetic Energy Recovery Switch (MERS) is studied. MERS is a simple configuration with low switching losses and simple control acting as a variable capacitor. Due to the special characteristics of this configuration, a new IGBT with low on-state voltage has been developed. The performance of the configuration has been confirmed with experiments on a 50 kW multi-pole permanent magnet generator. Numerical investigations on large scale system indicate potential for loss reductions and power semiconductor rating reduction compared to using an active rectifier solution.

Practical Implementation of Hysteresis Control for Maximum Power Point Tracking of a Permanent Magnet Generator Wind Turbine

A permanent magnet wind turbine is to track a dynamically changing wind from measurements of the wind speed and the rotor speed. Issues of determining the effective wind speed at the turbine rotor are investigated as well as the optimum control strategy to maintain operation at the maximum power point. This is implemented using a hysteresis control system based on the turbine tip speed ratio and then tested on a permanent magnet generator wind turbine in a dynamic wind environment. This showed a small increase in the energy output using the controller. Methods to increase the energy output further are investigated by simulation.

PM Wind Generator Topologies

The objective of this paper is to provide a comparison among permanent magnet (PM) wind generators of different topologies. Seven configurations are chosen for the comparison, consisting of both radial-flux and axial-flux machines. The comparison is done at seven power levels ranging from 1 to 200 kW. The basis for the comparison is discussed and implemented in detail in the design procedure. The criteria used for comparison are considered to be critical for the efficient deployment of PM wind generators. The design data are optimized and verified by finite-element analysis and commercial generator test results. For a given application, the results provide an indication of the best-suited machine.