Resonantlest Set with PD Eree| Detailed introduction of technical principles

The partial discharge-free induced withstand voltage resonant equipment is a specialized system for conducting induced withstand voltage tests on winding equipment such as transformers and instrument transformers.

Test Principle: Its core technology is "series resonance." By adjusting the inductance of an adjustable reactor, it resonates in series with the stray capacitance of the test object at an increased test frequency (typically 100-300Hz). At the resonance point, the circuit is purely resistive, and the power supply only needs to provide a small amount of active power to generate a partial discharge-free resonant test device on the test object. This includes partial discharge-free AC resonant test systems and resonant test systems with partial discharge (single-phase 450kW).

The partial discharge-free induced withstand voltage resonant test system can be used for AC withstand voltage tests and partial discharge tests on all electrical equipment.

It utilizes an excitation transformer to excite a series or parallel resonant circuit. By adjusting the output frequency of the variable frequency power supply,

the inductance L of the reactor and the capacitance C of the test object resonate in the circuit. The resonant voltage is the voltage applied to the test object. Alternatively, it can be directly output to the primary winding of a transformer through an intermediate transformer for induced withstand voltage testing.

1. Excellent test equivalence. The output of this device is a sine wave with minimal waveform distortion. The waveform distortion rate is <3%, unlike other types of frequency converters (which output square waves, which are then shaped into sine waves). Therefore, peak value measurement is not required during the test.

2. Fiber optic control completely isolates the high-voltage and low-voltage control circuits.

3. Small size, light weight, and flexible transport, making it ideal for field use.

4. Simple and convenient operation and wiring, improving work efficiency by 50% (compared to generator sets).

5. Safe and reliable, the device incorporates multiple protections, including: discharge breakdown protection, overvoltage setting protection, output short-circuit protection, start-up zero-position protection, bridge arm amplification circuit protection, and power curve protection. When any of these protections occur, the device immediately disconnects the test voltage output and cuts off the main circuit power supply, ensuring the safety of the test personnel, the test object, and the test system. 6. The signal source in the device is generated by a dedicated chip and controlled by a microcomputer, resulting in high output frequency stability, reaching 0.01Hz.

7. The frequency converter output voltage is controlled by a high-speed microcomputer, with an output voltage instability of <1%.

8. Selectable manual/automatic boost switching

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

2. Rated Output Power: Single-phase 450kW

3. Output Frequency Range: 20Hz～300Hz, continuously adjustable; 0～350V, continuously adjustable

4. Rated Output Voltage: 0～350V, continuously adjustable

5. Rated Output Current: 0～1286A, continuously adjustable

6. Frequency Instability: <0.05%

7. Voltage Instability: <1.0%

8. Nonlinear Distortion: <1.0%

9. Partial Discharge: <10pC (Measured on the high-voltage side of the boost transformer)

10. Operating Conditions: Temperature -10℃～+45°C, Humidity: 10-90%RH

11. Cooling Method Forced air cooling;

Partial discharge-free induced withstand voltage resonance test system; Partial discharge-free frequency conversion series resonance test device; Partial discharge-free frequency conversion series resonance test device;

MSWJXZ Partial discharge-free resonance test device; Partial discharge-free AC resonance test system; Resonance test system with partial discharge.