Line Parameter Tester

Transmission Line Parameter Tester

The Transmission Line Parameter Tester is a high-precision instrument for field testing power frequency parameters of various high-voltage transmission lines (overhead, cable, overhead-cable hybrid). Featuring an integrated design with a built-in variable-frequency power supply module, it provides variable-frequency voltage-regulated output power. Frequencies can be varied to 47.5Hz/52.5Hz, 45.0Hz/55.0Hz, 57.5Hz/62.5Hz, or 55.0Hz/65.0Hz. Employing digital filtering technology, it avoids interference from power frequency electric fields during testing, fundamentally resolving the challenge of accurate measurement under strong electric field interference. It is also suitable for testing scenarios where power is supplied by generators after complete power outage.

With grid expansion and increasingly constrained transmission corridor land availability, multi-circuit installations on the same tower have become commonplace. This trend has intensified coupling between transmission lines, leading to significantly stronger interference during power frequency parameter testing. Such interference severely compromises measurement accuracy and the safety of testing equipment. To address this challenge, we have developed a new-generation transmission line heterodyne parameter testing system. This system integrates a variable-frequency test power supply, precision measurement modules, high-speed digital processing chips, and proprietary patented anti-inductive voltage circuitry. This system effectively eliminates the impact of strong interference, ensures the safety of instruments and equipment, and enables extremely convenient, rapid, and accurate measurement of power line power frequency parameters.

1) Full-Touch Extra-Large LCD Display

The instrument features a 7-inch large-screen touch-sensitive color display with an extra-large full-touch interface for simple operation. All steps are clearly displayed via English menus, requiring no additional professional training for operators. A single touch completes the entire measurement process, making it an ideal intelligent measurement device.

2) Compact Size and Lightweight Design

Its minimal footprint and lightweight construction provide the simplest and most convenient testing solution.

3) Simple and Convenient Power Connection

All measurement processes require only a standard 220V AC power supply, eliminating the inconvenience of connecting to 380V power sources common in existing measurement methods.

4) Exceptional Induced Voltage Resistance

The instrument incorporates a unique anti-induced voltage circuit, ensuring it can withstand higher induced voltages (with anti-induced current capability up to 60A) and operate normally under 30,000V induced voltage.

5) Direct Measurement of Induced Voltage and Current

The instrument's unique anti-induced voltage circuitry enables it to withstand higher induced voltages, allowing direct measurement of both induced voltage and current. It can also determine whether the instrument can measure the circuit.

6) Variable Frequency Technology, Precise Measurement

High interference resistance is achieved through an internal variable-frequency power supply module that provides the instrument's measurement output power. The frequency can be adjusted to 47.5Hz/52.5Hz, 45.0Hz/55.0Hz, 57.5Hz/62.5Hz, or 55.0Hz/65.0Hz. Combined with digital filtering technology, this effectively avoids various power frequency interference signals in the field, enabling the instrument to achieve high-precision, accurate, and reliable measurements.

7) High-Speed Processor

Precise and rapid, the instrument employs a professional high-speed digital signal processor as its processing core. This significantly enhances computational capabilities while ensuring measurement accuracy.

8) Simple Operation

External wiring is straightforward. All measurements-positive-sequence impedance, zero-sequence impedance, positive-sequence capacitance, and zero-sequence capacitance-can be completed by connecting a single test lead to the circuit under test at the test terminals. This eliminates issues inherent in existing testing methods, such as cumbersome wiring changes, interference susceptibility, stability concerns, and accuracy limitations. It also prevents potential harm to operators from induced voltages during wiring adjustments.

9) Massive Data Storage

The instrument incorporates a calendar chip and large-capacity memory, enabling chronological storage of test results. Historical data can be reviewed at any time and printed for output.

10) Scientific and Advanced Data Management

Instrument data can be exported via USB drive for viewing and management on any PC, enabling the creation of work reports.

11) Operational Safety Protection

The instrument incorporates a dedicated grounding detection function to verify proper grounding at the test site. If grounding is loose or absent, the instrument automatically detects this and prohibits operation, ensuring personnel safety and protecting the instrument.

I. Compatible Line Types

- Overhead transmission lines (single-circuit/multi-circuit on the same pole)

- Power cable lines (single-core/three-core, various insulation materials)

- Overhead-cable hybrid lines

II. Core Application Scenarios

1. Pre-commissioning of new lines: Verify construction quality by measuring positive-sequence/zero-sequence impedance, capacitance, mutual inductance, and other parameters.

2. Maintenance of operational lines: Periodically re-measure parameters to assess line aging and coupled interference impacts, ensuring stable power supply.

3. Post-line modification: Validate performance compliance after modifications such as phase shifting or capacity expansion.

4. Off-grid scenarios: After complete power outage, testing can be completed using ≥3KW generator power supply.

5. High-interference environments: Accurate measurement of critical parameters under coupled interference from multiple circuits on the same pole.

III. Key Test Items

Includes measurement of induced voltage/current, positive-sequence/zero-sequence impedance, positive-sequence/zero-sequence capacitance, line mutual inductance, coupled capacitance, and other parameters.