Non-destructive Measurement of Magnetic Properties of Claw Pole

Abstract

The magnetic properties of the claw pole have a direct effect on the output power of a generator. Many methods can be used to measure these magnetic properties, each with its own advantages, but an important shortcoming is that all are destructive. In this study, a new non-destructive method to measure the magnetic properties of claw pole was proposed and a corresponding testing setup was designed. A finite-element model was constructed to simulate the measurement process. Results proved that the measured magnetization-like curves had good agreement with the trend of the input magnetic curves and the effect of the positioning error in the measuring process could be neglected. To further validate the new method, seven types of claw poles of different materials subjected to different heat-treatment processes were forged and tested by both the new method and the conventional ring-sample method. Compared with the latter, the new method showed better consistency, relatively higher accuracy, and much stronger stability of measurement results; however, its sensitivity needs to be improved. The effects of material compositions and heat-treatment parameters on the magnetic properties of the claw pole were briefly analyzed.

Suitable claw shape design for improving the magnetic properties of forged claw pole parts in generator

“…In NDTEM, the designed magnetic circuit has a high degree of similarity with the magnetic circuit formed by a claw pole working in a motor. The NDTEM has been proved to have better consistency, accuracy and stability than the conventional ring-sample method that is used daily in industry [18] to evaluate the [17]. An air gap of 0.2 mm was found to be optimal for improving the sensitivity of the NDTEM [19].…”

“…In NDTEM, the designed magnetic circuit has a high degree of similarity with the magnetic circuit formed by a claw pole working in a motor. The NDTEM has been proved to have better consistency, accuracy and stability than the conventional ring-sample method that is used daily in industry [18] to evaluate the The NDTEM can accurately and reliably measure the magnetic properties of claw poles without damaging them [17]. An air gap of 0.2 mm was found to be optimal for improving the sensitivity of the NDTEM [19].…”

“…The NDTEM [17] is used as a replacement for the power generation test of installed generators to measure and compare the magnetic properties of claw pole. In NDTEM, the designed magnetic circuit has a high degree of similarity with the magnetic circuit formed by a claw pole working in a motor.…”

A Practical Model Study on the Mechanism of Clay Landslide under Static Loads: From the Perspective of Major Crack–Stress–Displacement

“…Furthermore, cracks in clay slopes may take on nonvertical plane shapes. For example, diagonal cracks are one of the common distribution patterns of clay cracks in Chengdu, Hefei, and Nanjing in China [37,38]. Unfortunately, in previous stability analyses of fractured slopes, the crack was assumed as vertical, so the nonvertical crack mode in clay is still poorly understood [27,39].…”

Preparation of Poly(acrylic acid) ‐Boron Nitride Composite as a Highly Efficient Adsorbent for Adsorptive Removal of Heavy Metal Ions

“…With the rapid development of economy, the modern industry has made great development, and the resulting environmental problems have become increasingly serious [1–3] . Especially the contamination of heavy metals caused the attention of people because the heavy metal ions can′t decompose and introduce the potential danger of bioaccumulation, which may eventually affect man through the food chain [4–6] . Therefore, it is very necessary to remove effectively heavy metal ions from waste water.…”