四極同步交流發電機的實作與探究

The Hands-on and Inquiry of Four-pole Synchronous Alternator

梁立國(Lih-Kuo Liang)

《物理教育學刊》 22卷2期 (2021/12) Pp. 1-15

https://doi.org/10.6212/CPE.202112_22(2).0001

摘要

兩個功率相近但結構差異大的四極直流馬達分別改裝成風力發電機與渦輪發電機。首先，量測發電機的基礎物理量，包括：漆包線徑、線圈電阻及其圍繞的截面積、鐵氧磁鐵大小、並估算線圈數；其次，線圈端點接上反向並聯的紅光LED及藍光LED，在家用風扇不同風速與水龍頭不同水流速下，以示波器測量端點電壓與交流頻率；最後，以法拉第感應電動勢公式得知鐵心磁通量密度發生在少於飽和磁通量密度三分之一處，並隨轉子頻率增加而減少。此外，藉由發電機的實作與探究，可具體理解發電機的電磁學原理與技術，包括：轉子與定子的組成、磁通量變化與感應電動勢發生、磁滯曲線造成的電磁能損失及各種不同型態發電機的結構。

關鍵字

直流馬達 ； 四極交流發電機 ； 法拉第感應電動勢 ； 磁通量密度

並列摘要

Two four-pole DC motors with similar power but large differences in structure were converted into wind generator and turbine generator. First, we measure the basic physical quantities of the generators, including: wire diameter, resistance, cross-sectional area around the coil, size of ferrite magnet, and estimate the number of turns of the coil; secondly, connect the red LED and blue LED in reverse parallel to the ends of the coil, and use an oscilloscope to measure the voltage and the frequency of the alternating current under different wind speeds of fan and different water flow rates of the faucet; finally, according to the Faraday's law of induction, it is known that the ferrite magnetic flux density occurs at less than one third of the saturation density and decreases with the increase of the rotor frequency. By the means of hands-on and inquiry of generators, we can further understand the electromagnetic principles and technologies of generators, including: the composition of the rotor and the stator, the change of magnetic flux and induced electromotive force, the loss of electromagnetic energy caused by the hysteresis curve and the structure of various types of generators.

並列關鍵字

DC motor ； four-pole alternator ； the Faraday's law of induction ； magnetic flux density