High current generator for power plants, substations, electrical appliance manufacturers, and research institutes



A high current generator (also often called a "current booster") and a test transformer are exactly "opposite" types of test equipment. If a test transformer is used to generate high voltage to test insulation, then a high current generator is used to generate high current to test the current-carrying capacity, thermal stability, and dynamic stability of electrical equipment.

In simple terms, its core function is to simulate a huge current far exceeding normal power supply capacity in a laboratory or on-site (usually at very low voltage, only a few volts to tens of volts), to test the performance of various electrical equipment and components under extreme conditions such as short circuits and overloads.

⚡ Core Uses of High Current Generators

High current generators are widely used in power plants, substations, electrical appliance manufacturers, and research institutes, mainly for the following scenarios:

Circuit breaker and switch testing: Verify whether protective devices such as air switches and fuses can accurately trip (open the circuit) within the specified time when encountering short-circuit faults, and whether they can withstand the enormous electrodynamic forces and heat at the moment of a short circuit.

Current transformer (CT) calibration: By injecting a standard high current into the primary side of the transformer, accurately measure the output on the secondary side to verify whether its ratio, polarity, and accuracy meet the standards.

Temperature rise tests for busbars, cables, and connectors: Apply high current for an extended period to simulate the operating state of equipment under full load or overload, and measure whether the temperature rise of wires, joints, busbars, and other parts complies with safety standards.

Relay protection device testing: Provide operating current for overcurrent relays, differential relays, etc., to test their operating and reset values, ensuring the coordinated action of the entire power protection system is accurate.

Testing of other current-carrying components: Test the characteristic changes of various resistors, impedance components, and semiconductor devices (such as thyristors) under high current conditions.

⚙️ Working Principle and Main Types

The core principle of a high current generator is essentially a special, high-power step-down current transformer (for AC type) or a high-power power supply (for DC type). It converts ordinary mains power (such as 220V or 380V) into an output with extremely low voltage (usually a few volts to tens of volts) but current as high as hundreds of amperes or even tens of thousands of amperes.

According to the technical route and function, they are mainly divided into the following categories:

Power frequency high current generator (traditional type): By adjusting the voltage of an auto-transformer, it controls the output of a 50Hz standard sine wave high current from the step-up current transformer. The technology is mature and the most widely used.

Intelligent/programmable high current generator (modern type): Uses power electronics technology (such as IGBT, thyristors) and microprocessor control. It has advantages such as small size, light weight, high precision, fully automatic testing, and strong anti-interference capability.

DC high current generator: Outputs DC high current through a rectifier circuit, specifically for testing DC equipment such as DC circuit breakers and DC transformers.

AC/DC integrated high current generator: Combines both AC and DC output functions, offering greater adaptability.