30kW Partial Discharge-Free Power Frequency Withstand Voltage Test System

The high-power output of the variable-frequency power supply unit is based on the principle of cascaded amplification. Starting from an initial signal source with very low power, the signal undergoes multiple stages of amplification to achieve high-power output that meets testing requirements.

The signal source uses a variable-frequency function generator to produce a standard sine wave signal, which is then voltage-adjusted via a digital potentiometer; this process also serves to adjust the frequency and voltage during testing. At this stage, the frequency matches the test frequency, and both frequency and voltage adjustments are performed within the signal source section. The signal source's output directly drives the "pre-amplifier," which provides an initial power output. This "pre-amplifier" is divided into two paths: one generates a "synchronous power supply" at the test frequency to power the partial discharge tester; the other drives the "bridge amplifier circuit." The "bridge amplifier circuit" is the primary component responsible for high-power generation; it generates a significant amount of heat during testing and requires an air-cooling system for heat dissipation.