Performance estimation method for in-service single-phase induction motors
This paper proposes a performance estimation method for single-phase induction motors in the field at any operating load using a set of data from in-service measurement. This paper describes the use of the improved equivalent circuit models based on double-revolving-field theory which a core loss element is properly added in order to provide more accurate results. The appropriate values for the model parameters can be evaluated by the use of measured data coupled with the genetic algorithms. The estimated performance result of several motors are presented and then compared to the measured values obtained from load tests, and clearly illustrate that agreement between the proposed method and the actual one is good.
A study of methods to measure the parameters of single-phase induction motors
Two methods for the experimental determination of single-phase induction motor parameters are studied. The one is a relatively complicated method based on single-phase measurements. The other utilizes a two-phase based strategy. An investigation was done to evaluate the accuracy with which the performance of a machine can be predicted using experimentally determined numerical values for the machine parameters, calculated from these two methods. Comparing the two sets of calculated performance values, shows that the two-phase method gives a better correlation with the measured values than the single-phase method. >
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.