power-frequency testing transformer

例句：

1. 1. The power-frequency testing transformer is used to measure the voltage and current in a power system.
   电力频率测试变压器用于测量电力系统中的电压和电流。
2. 2. The power-frequency testing transformer is essential for maintaining the stability of the power grid.
   电力频率测试变压器对于保持电网的稳定性至关重要。
3. 3. The power-frequency testing transformer was developed to improve the accuracy of power measurement.
   电力频率测试变压器的开发是为了提高电力测量的准确性。