frequency variation

基本解释

The improved algorithm can track frequency variation of the time-varying signal with no extra calculation burden.
对算法进行了改进，在不增加计算量的情况下，实现了对频率变化的跟踪。
When vehicles passing ring coil detector, the interaction of vehicle body's substance and ring coil changes resonant frequency of the ring coil and forms a curve of frequency variation.
车辆通过环形线圈检测器时，车体物质与环形线圈相互作用改变了线圈的谐振频率，从而形成频率变化曲线。
For Shanghai power grid, which has large short circuit capacity and short electrical distance, a method using imported instrument to test power frequency variation distance protection is presented.
结合上海电网具有短路容量大、电气距离短的特点，提出了使用进口仪器测试工频变化量距离保护的具体方法。

变频
In this part,the thesis first presents the energy saving principle of speed regulation of pumps through frequency variation.
首先,本文介绍了变频调速的基本原理。