Tester Parameters
1. High voltage output: 0.5 ~10kV, each step increases by 500V, total 20 steps
High voltage output cable can be used dragging on the ground
Three frequencies: 45Hz, 50Hz, 55Hz
2. Capacity: 1500VA
3. Accuracy: tgδ: ±(reading*1.0%+0.08%)
Cx: ±(reading*1.5%+5PF)
4. Resolution: tgδ:0.01% Cx:1pF
5. Measurement range: 0.1% < tgδ < 50%
3PF< Cx < 60000PF
At 10KV, Cx ≤30000PF
At 5KV, Cx ≤60000PF
6. Power supply: AC 220V士10% 50士1Hz
7. Harmonic adaptation: ≤3%
8. Operating conditions: -15℃-50℃ relative humidity <80%
9. Dimensions: 460(L)×335(W)×340(H)
10. Weight: 30 kg
Working principle:
After the heterodyne dielectric loss tester starts measurement, the high voltage set value is sent to the variable frequency power supply. The variable frequency power supply uses PID algorithm to slowly adjust the output to the set value. The measurement circuit sends the actual high voltage to the variable frequency power supply, fine-tunes the low voltage, and achieves accurate high voltage output. According to the positive/reverse wiring settings, the measurement circuit automatically selects the input and switches the range based on the test current. The measurement circuit uses Fourier transform to filter out interference, separates the fundamental wave of the signal, performs vector operations on the standard current and the test current, calculates capacitance from amplitude, and calculates tgδ from phase difference. Multiple measurements are repeated, and a middle result is selected after sorting. After measurement, the measurement circuit sends a voltage reduction command, and the variable frequency power supply slowly reduces the voltage to 0.
