Fault diagnosis and condition monitoring of axial-flux permanent magnet wind generators

Sizing of Wind Powered Axial Flux Permanent Magnet Alternator Using Analytical Approach

“…In Fig. 3, is the effective length of the stator core in radial direction, is the outer diameter with radius , is the internal diameter with radius is the air gap length, is the average diameter of the stator given in equation (1). That is:…”

“…Hydro power, wave power, solar energy, biomass and wind power are being harnessed in various capacities. Wind energy plays a central role in most countries' immediate and long term energy plans with total installed commercial capacity totaling 370 GW in 2014 [1]. While in Nigeria, wind energy remains largely untapped despite a bright prospect of wind power as one of the lowest cost renewable energy resources [2].Using wind power to produce electricity is a perfect choice for direct drive since maintenance requirement will be significantly reduced [3], low cost applications in the development of renewable energy and has been found largely reliable with new advances in wind energy technology [4].…”

“…These have advantages of high efficiency and reliability, since there is no need of external excitation and conductor losses are absent from the rotor. Basically, PM machines can be divided into radial-flux machines (RFM) and axial-flux machines (AFM), according to the flux direction in the air gap [1,13]. Transverse flux machines (TFM) exist, but do not seem to have gained a foothold in wind power generation [13] and hence, are rarely discussed.…”

“…Axial-flux machines have now been adopted as the solution for certain applications such as electric traction or elevation [14] due to its advantages. Varieties of Axial Flux Permanent Magnet (AFPM) Machines have been presented in [1,13,15] with some notable advantages such as compact machine construction and short frame, hence, smaller in size than their radial flux counterparts [15]; high power density; high efficiency [16] since there is no rotor copper losses due to the permanent-magnet excitations; more robust structure than cylindrical type; can be designed to have a higher power-toweight ratio resulting in less core material and higher efficiency [7,[15][16][17][18], the compactness and disk-shaped profile make these type of machines particularly suitable for mechanical integration with wind turbines [11]. It has also got its drawbacks which include the existence of complicated machine topology with two air gaps [19]and high windage losses at high-speed applications which can be decreased to some extent by placing the machine in a vacuum seal, especially when combined with a flywheel [20].…”

Study of a Combined Demagnetization and Eccentricity Fault in an AFPM Synchronous Generator

“…During recent years, the demagnetization and the eccentricity fault have also been studied in the AFPM synchronous machine. More specifically [2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21]] study the eccentricity fault, while [21][22][23][24][25][26][27][28][29][30] investigate the demagnetization fault in AFPM synchronous machines. In [31] a combined eccentricity and demagnetization fault in a double-sided AFPM synchronous machine using a time analytical model is presented.…”