Instrument Transformer Short-Time Current Test System

System Overview

The short-time current test system for instrument transformers is primarily designed for dynamic and thermal stability testing of distribution network electrical equipment, such as current transformers rated at 35kV and below.
The system utilizes high-efficiency energy storage and power electronic inverter technologies to generate controllable, high-capacity short-duration test voltages and currents, meeting the testing requirements for a wide range of distribution network equipment. Through units dedicated to charging, energy storage, and inversion, the system isolates itself from the utility grid, thereby preventing transient test surges from impacting the power supply side.
Built with military-grade, long-life, high-energy storage capacitors alongside mature digital control and power inverter units, the system offers exceptional durability. Additionally, its flexible SPWM modulation scheme allows for easy adjustment of test parameters across a wide range.
Employing power electronic conversion technology, the system enables rapid adjustment of output current amplitude, facilitating convenient short-time current testing for instrument transformers.
The system features a current prediction function that minimizes the impact of changes in circuitry or test samples, enhancing ease of use in field applications.
◎ Standard specifications: 40kA/100kA, 4s. Output current, test items, and operating modes can be customized according to specific requirements.

Working Principle

The operating principle of the test system is as follows: the power supply feeds the charging transformer via a contactor; the charging transformer is a multi-winding step-up transformer that rectifies the stepped-up voltage to charge the energy storage unit; the energy stored in the unit is converted by a single-phase inverter into an SPWM waveform, which is then applied to the test object.