In the traditional test of power frequency parameters of transmission lines, three-phase auto-transformers and large-capacity isolation transformers are used to provide test power. CT and PT for power measurement are used to convert electrical signals. Finally, pointer-type high-precision voltmeters and ammeters are used. The power meter measures each electrical parameter, and finally calculates the test results of the power frequency parameters of the transmission line. Making the entire set of test equipment large and heavy requires cranes to work with it, which is very unfavorable for on-site measurement, and because the test power source is a power frequency power source, it is easy to mix with the coupled power frequency interference signal, which causes a large measurement error. The signal-to-noise ratio needs to be greatly improved, which further increases the capacity and volume of the power supply.

This instrument can accurately measure various high-voltage power transmission lines (overhead, cables, mixed overhead cables, power frequency parameters installed on multiple poles on the same pole (positive sequence capacitance, positive sequence impedance, zero sequence capacitance, zero sequence impedance, mutual inductance and coupling capacitance). Etc.), fully meet the requirements of the "Start up and Acceptance Regulations of 110kV and above Transmission and Transformation Infrastructure Construction Projects", DL / T559-94 "220-500kV Power Grid Relay Protection Device Operation Setting Regulations", and "GB50150-2006".

The instrument adopts an integrated structure, with a built-in frequency conversion power module, which can convert the frequency and regulate the output power. Digital filtering technology is used to avoid the interference of the power frequency electric field to the test, and the problem of accurate measurement under strong electric field interference is fundamentally solved.

1. Quickly and accurately complete the test of the positive sequence capacitance, zero sequence capacitance, positive sequence impedance, zero sequence impedance and other parameters of the line, and also measure the mutual inductance and coupling capacitance between the lines

2. Strong anti-interference ability, can accurately test under the condition that the ratio of the inter-frequency signal to the power frequency signal is 1:10;

3. The external wiring is simple, and all the line parameter tests can be completed by only accessing the lead wires of the circuit under test once; thoroughly solving the problems of tedious test wiring, interference, stability, and accuracy in the existing testing methods.

4. The instrument uses a high-speed single-chip microcomputer as the core to realize the integration of test power, instrumentation, and calculation models, and condenses the equipment of a truck into one instrument.

5. The instrument adopts a 320 * 240 large-screen dot-matrix liquid crystal display, the rotary mouse is imported from the United States, and the embedded micro printer prints the results. The operation is very simple;

6. The instrument test process is fast, the instrument automatically completes the test mode control, buck control and data measurement calculation, and prints the test results, a sequence parameter measurement is completed in one minute, the test time is shortened, the workload is greatly reduced, within 20 minutes Can complete the workload of two hours of traditional methods;

7. High test accuracy. The instrument itself provides three sets of different frequency power sources close to the power frequency (42.5Hz / 57.5Hz 45Hz / 55Hz 47.5Hz / 52.5Hz) to choose from, which can easily separate power frequency and clutter interference, and effectively achieve small High-precision measurement of signals;