電力公司透過電力系統將交流電力送至用戶端，但用戶端電力設備的負載特性不同，會造成電力虛功的損失及諧波電流過大等問題。 負載特性可分為電阻性、電容性及電感性，這三種的電壓(v)、電流(i)及功率( p)如圖1-3所示。 <img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___1.jpg" alt="" /> 
圖1 電阻性負載之電路簡圖與波形 <img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___2.jpg" alt="" />
圖2 電容性負載之電路簡圖與波形 <img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___3.jpg" alt="" /> 圖3 電感性負載之電路簡圖與波型 
<img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___1-7.png" alt="" /> <img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___8-11.png" alt="" /> <img src="https://edit.wpgdadawant.com/uploads/news_file/blog/2019/823/tinymce/___12-13.png" alt="" /> &nbsp;

功率因數修正原理