PD Variable Frequency Power Supply

Partial-discharge-free variable-frequency power supplies can be used for AC withstand voltage tests and partial-discharge tests on all types of electrical equipment. By using an excitation transformer to drive a series or parallel resonant circuit, and adjusting the output frequency of the variable-frequency power supply, resonance is induced between the inductance L of the reactor in the circuit and the capacitance C of the test specimen; the resonant voltage is the voltage applied to the test specimen. Alternatively, the output can be fed directly to the primary winding of a transformer via an intermediate transformer to perform an inductive withstand voltage test.

4.1 Rated Input Voltage: Three-phase AC 380 V ±10%, 50 Hz.

4.2 Rated Output Power: Single-phase 450 kW.

4.3 Output Frequency Range: 20 Hz to 300 Hz, continuously adjustable.

4.4 Rated Output Voltage: 0 to 350 V, continuously adjustable.

4.5 Rated Output Current: 0–1286 A, continuously adjustable.

4.6 Frequency Instability: ≤0.05%.

4.7 Voltage Instability: ≤1.0%.

4.8 Nonlinear distortion: ≤1%.

4.9 Partial discharge: ≤10 pC (measured on the high-voltage side of the step-up transformer).

4.10 Operating conditions: Temperature: –10°C to +45°C; Humidity: 10–90% RH; Altitude: ≤1000 meters.

4.11 Cooling method: Forced air cooling.