Newly installed and overhauled generators usually require a series of characteristic tests before being put into operation to ensure operational safety and stability after grid connection. Load tests are extremely time-consuming and labor-intensive, mainly including the short-circuit characteristic test and no-load characteristic test.

The short-circuit characteristic test involves gradually increasing the excitation current (after short-circuiting the three-phase output terminals) until the three-phase short-circuit current reaches the rated current. It mainly tests the current-carrying capacity of the windings and verifies the current output characteristics.

The no-load characteristic test involves gradually increasing the generator's excitation current until the three-phase output voltage of the generator reaches the rated voltage. It mainly tests the insulation performance and voltage output characteristics of the generator.

The Relaystar-1800 Six-Phase Relay Protection Tester integrates the full-function calibration of relay protection and on-site waveform recording test functions. In addition to performing various protection calibration functions, it can also complete test items such as generator outlet short-circuit characteristic test, generator no-load characteristic test, field extinction characteristic test, start signal waveform recording test, transformer no-load characteristic test, and no-load curve measurement.

△ 6U/6I Full-Function Relay Protection Tester + Portable Waveform Recorder

The Relaystar-1800 Six-Phase Relay Protection Tester is equipped with power system data acquisition and waveform analysis software, and has a built-in portable waveform recorder for real-time signal recording on site. It can read, edit and analyze waveform files in COMTRADE format, and also collect waveform data uploaded by the lower computer for long-term online waveform recording.

Select the Comprehensive Function test on the main interface, and click the Fault Playback and Waveform Recording Analysis button to perform waveform recording, waveform playback, waveform analysis and waveform editing.

By opening the waveform file, the following functions can be realized: starting online waveform recording, setting recording parameters, fault playback, waveform monitoring and analysis, waveform display in Y mode, waveform display in delta mode, proportional display of vertical voltage and current of waveforms, vertical (height) zoom in and out of waveforms, and screenshot saving of waveforms.

The data waveform display area includes channel points, time, maximum and minimum values, etc.

According to the characteristic curve presented by the generator excitation system during field extinction, the waveform recorder of the Relaystar-1800 Six-Phase Relay Protection Tester is used for waveform recording.

Characteristic curve analysis through recorded waveforms can determine whether there is an interturn short circuit in the rotor coil and a local short circuit in the stator core. If a short circuit exists, the eddy current demagnetization effect here will cause the excitation current to increase to reach the rated voltage. For the generator's voltage change rate and unsaturated synchronous reactance, the generator's operating condition when the voltage changes and the setting of the field resistance are analyzed and judged through no-load characteristic analysis. Based on the generator outlet short-circuit characteristic test, the presence of interturn short circuits in the rotor coil can be determined: when an interturn short circuit occurs in the rotor coil, the short-circuit current will decrease for the same excitation current due to the reduction in ampere-turns.

By integrating the full-function calibration of relay protection and on-site fault waveform recording test functions, the Relaystar-1800 Six-Phase Relay Protection Tester avoids the need to carry multiple electrical devices such as waveform recorders, generator impedance testers and insulation characteristic testers repeatedly for on-site maintenance. It also ensures the consistency and reliability of test data, making the test results more intuitive, authentic, real-time and effective.