The instrument can measure high-voltage electrical equipment that is ungrounded or directly grounded using the positive and reverse wiring methods. It can also measure the tgδ and the main capacitance C1, C2 of capacitive voltage transformers.
The instrument is equipped with a high-voltage step-up transformer and has safety protection measures such as zero-crossing closing and lightning protection. During the test, it outputs high voltages of different levels from 0.5KV to 10kV, making operation simple and safe.
Instrument Features
◆ Simple operation, Chinese display, printing
◆ Convenient to use, no conversion needed
◆ The variable frequency dielectric loss tester has its own high voltage, strong anti-interference ability, and short test time.
Instrument Characteristics
Tester Parameters
| 1. | Due to the adoption of frequency conversion technology, it can ensure accurate measurement under strong electric field interference. |
| 2. | The instrument is operated with a Chinese menu, and the microcomputer automatically completes the entire measurement process. |
| 3、 | This instrument is also suitable for measuring the tgδ and capacitance of high-voltage electrical equipment in workshops, laboratories, and scientific research institutions; it also has the advantages of convenience, simplicity, and accuracy for the loss test of insulating oil. |
| 4、 | The instrument can measure high-voltage electrical equipment that is ungrounded or directly grounded using the positive and reverse wiring methods. It can also measure the tgδ and the main capacitance C1, C2 of capacitive voltage transformers. |
| 5、 | The instrument is equipped with a high-voltage step-up transformer and has safety protection measures such as zero-crossing closing and lightning protection. During the test, it outputs high voltages of different levels from 0.5KV to 10kV, making operation simple and safe. |
1、High voltage output: 0.5 ～10kV, each step increases by 500V, a total of 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 variable frequency dielectric loss tester starts the measurement, the high voltage set value is sent to the variable frequency power supply. The variable frequency power supply uses the PID algorithm to slowly adjust the output to the set value. The measurement circuit sends the actual measured 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 product current, calculates the capacitance from the amplitude, and calculates tgδ from the phase difference. It repeats the measurement multiple times, sorts the results, and selects a middle result. After the measurement is completed, the measurement circuit sends a voltage reduction command, and the variable frequency power supply slowly reduces the voltage to 0.
