Transmission Line Tester

LP-II frequency shift line parameter test device

Performance characteristics:

1. The device is equipped with high internal resistance induced voltage test accessories. After connecting to the device test channel, it can quickly and accurately complete the electrostatic induced voltage and phase angle measurement of three-phase and two-phase transmission lines when the end of the line is open.

2. It can complete the measurement of power frequency electromagnetic induction voltage, power frequency interference current, phase angle and zero-sequence power frequency interference current of each phase of the tested line when the three-phase and two-phase transmission lines are short-circuited at the end of the line.

3. Automatic test of positive sequence impedance, zero sequence impedance, positive sequence capacitance, zero sequence capacitance and other parameters of three-phase and two-phase transmission lines (including DC transmission lines and DC grounding electrode lines). The wiring at the first end of the line test is reversed. It is automatically completed inside the device. It only needs to connect the first end of the three-phase and two-phase lines once, and change the wiring (grounded or suspended) at the end to complete all test items, which greatly improves the efficiency of on-site testing.

4. A three-phase high-current relay is installed inside the device to automatically control the grounding operation of the three-phase and two-phase first-end line side of the tested line, and cooperate with the conversion of the positive sequence and zero sequence test wiring and signal acquisition. The test process does not require Any manual switching of the first-end test wiring can avoid damage to testers due to line induced voltage when changing wiring, and ensure the safety of equipment.

5. 8 channels of voltage and current measurement with independent ranges ensure the accurate test of zero sequence mutual impedance and zero sequence coupling capacitance between multiple circuits on the same pole or parallel circuit, and test the single phase caused by mutual inductance. Voltage asymmetry caused by unbalance and coupling is convenient for dispatching department to adjust line protection setting parameters.

6. The anti-interference ability is super strong. The built-in power frequency interference suppression device can resist up to the first and last ends of the tested line. After the first and last ends of the tested line are grounded, the line parameters of the power frequency interference current on the tested line under the condition of 20A to 100A can be tested normally. The principle of interference is that the isolation transformer of the device is specially designed and supplemented by an induced voltage suppression module to form a low resistance discharge channel for the interference voltage on the line to the ground.

7. The line impedance parameter test frequency selects 45Hz and 55Hz dual-frequency automatic test, which has better test equivalence. The capacitance test frequency is 260Hz single frequency test, which solves the problem of the test accuracy of ultra-short distance line capacitance parameters.

8. The different frequency power supply inside the device has good fine-grained step-and-boost control. The output voltage and current of the power supply can be automatically adjusted through the pre-check program, which solves the problem of parameter testing of ultra-short lines and large cross-section cables.

9. The latest mathematical algorithms and the selection of 16-bit high-precision AD chips ensure the purity and high fidelity of the device's different frequency output signal. When the test signal and the interference signal are 1:20 times, the difference frequency can be accurately The test signal is completely separated from the power frequency interference signal to accurately test the power frequency parameters of the line.

10. The test device adopts single-phase 220V power supply, which is convenient to use single-phase generator power supply to complete all test items on site, and has the function of alarming and protecting the working power supply misconnection of 380V.

11. High reliability, the internal frequency power supply of the device has multiple protections such as overvoltage, overcurrent, short circuit, overheating, etc. The operation panel is equipped with a manual emergency stop button, which ensures that the test will be manually closed immediately in the event of any accident at the parameter test site The power is output, and the device automatically grounds the three-phase first-end line to ensure the safety of equipment and testers.

12. The device comes with a test grounding goodness detection function, which can not only ensure that the device power supply does not start output in the case of poor grounding, but also avoids the occurrence of deviations in the zero sequence impedance parameter test of the line due to poor grounding.

13. The device has a pre-detection function for the terminal wiring status of the tested line. The wiring method is pre-inspected according to the attributes of the test item. At the same time, it prompts whether the wiring method of the line end is consistent with the test requirements, such as whether each phase is floating or short-circuited to ground. The data reliability of the line parameter test is guaranteed.

14. The instrument is equipped with a calendar chip and a large-capacity memory, which can automatically save the test results according to the test number or time sequence. The historical records can be read at any time and can be printed out.

15. The stored data of the instrument can be exported using a USB flash drive through the USB interface of the device panel, which can be used on any PC to facilitate the user to manage the test data and edit the line power frequency parameter test report.

Technical index:

1. Applicable line length: 1-500km

2. Anti-interference ability: Reliable and stable output under the condition that the ratio of the output signal of the device to the power frequency interference signal is 1:20, and the power frequency interference signal is accurately separated and all test items are completed.

3. Power supply: single-phase AC 220V±10%, (10~40A) 50Hz±2%;

4. Different frequency power output characteristics:

1) Output frequency: 45Hz/55Hz/260Hz fixed frequency output, the frequency is better than ±0.1%;

2) Output waveform: standard sine wave, waveform distortion is better than ±2%;

5. Different frequency power supply: 3kVA

6. Maximum output current: 10A

7. Maximum output voltage: 200V

8. Anti-power frequency interference current: 40A measurement accuracy ±0.2% ±2 words, the highest resolution is 0. 01mA

9. Electrostatic induction voltage: 20kV measurement accuracy ±5%±5 words, the highest resolution is 0. 001kV

10. Electromagnetic induction voltage: 0-600V measurement accuracy ±0.2% ±2 words, the highest resolution is 0. 001V

11. Applicable voltage level: 220kV and below

12. Impedance test range: 0.2~400Ω, the highest resolution: 0.001Ω;

When ≥1Ω, ±1% of reading ±5 words;

When <1Ω, ±2% of reading ±5 words;

Impedance angle: 0°~360°; ±1% of reading ±0.05°

13. Capacitance test range: 0.1μF~50μF, the highest resolution: 0.0001μF

When ≥0.1μF, ±1% of reading ±5 words;

When <0.1μF, ±2% of reading ±5 words;

Contact us

No. 255, Shanpu Road, Hedong Industrial Park, Wuzhong Economic Development Zone, Suzhou City, Jiangsu Province



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