variable-frequency power sources

例句：

1. 1. The new solar panel has a variable frequency power source that can adjust the output voltage according to the weather conditions.
   这款新型太阳能板拥有一个可变频率电源，可以根据天气条件调整输出电压。
2. 2.The variable frequency power source is essential for maintaining the stability of the electric grid.
   可变频率电源对于保持电网的稳定性至关重要。
3. 3.The variable frequency power source is widely used in various industrial applications, such as power generation and transportation.
   可变频率电源在各种工业应用中广泛使用，如发电和运输。