Series Frequency Conversion Resonance Test Device and Precise Locking of Resonance Frequency



Excitation Transformer

Combined with your previous understanding of ultra-low frequency high voltage generators, DC high voltage generators, and other equipment, the Series Frequency Conversion Resonance Test Device can be considered the "heavy weapon" in the family of power withstand voltage tests.

It mainly solves the problem that traditional equipment lacks sufficient power and is too bulky when conducting power frequency withstand voltage tests on large-capacity, high-voltage equipment (such as ultra-long high-voltage cables and large generators) on site. Here is a detailed analysis of this device:

⚡️ Core Working Principle

The core principle of this device is LC series resonance. It adjusts the output frequency of the variable frequency power supply to cause the inductance (L) of the high-voltage reactor in the circuit to resonate in series with the capacitance (C) of the test object.

When the circuit frequency meets the formula f = 1 / (2π√LC), the circuit resonates. At this time, the voltage obtained on the test object is Q times the output voltage of the excitation transformer (Q is the quality factor of the system, usually reaching tens to hundreds of times). This means that the power supply only needs to provide a small portion of the active power loss in the circuit (1/Q of the test capacity) to generate an extremely high test voltage on the test object.