High current generators are mainly classified based on the type of output current and structural form, with different types corresponding to different application scenarios.
I. Classification by Current Type
AC High Current Generator
Core Features: Outputs a pure 50Hz sinusoidal current with a small ripple coefficient, capable of accurately simulating grid conditions.
Typical Application Scenarios: Used for testing AC equipment such as transformers, switches, and current transformers.
DC High Current Generator
Core Features: Outputs a constant and stable DC current, suitable for testing DC equipment.
Typical Application Scenarios: Used for performance testing of DC circuit breakers, thyristors, battery packs, and other DC equipment.
II. Classification by Structural Form
Integrated Type
Core Features: The control and current boosting parts are integrated, making it compact, lightweight, and easy to move and connect on-site.
Capacity Range Reference: Generally suitable for equipment with an output current ≤ 2000A.
Split Type
Core Features: The control box and current booster are separated, solving the problem of excessive size and weight for high-capacity equipment, and facilitating single-person handling and operation.
Capacity Range Reference: Generally suitable for high-power equipment with an output current ≥ 3000A.
III. Core Application Scenarios
High current generators are essential equipment in the manufacturing, installation, and maintenance of power equipment, with the following main application scenarios:
Protection Device Calibration: Simulating short-circuit or overload currents to test the action threshold and time of protection devices such as circuit breakers, thermal relays, and current relays, ensuring reliable operation of the devices.
Current Transformer (CT) Testing: Applying current on the primary side to verify the accuracy of the CT’s ratio, polarity, and excitation characteristics.
Temperature Rise and Current Carrying Capacity Tests: Applying rated or specified test currents to electrical equipment such as switches, busbars, and cables to test their heating conditions and heat dissipation performance during long-term operation.
Factory and R&D Testing: Used for quality inspection of products such as motors, switches, and fuses in electrical manufacturing plants; used by research institutes to study the performance of equipment under high current conditions.
IV. Key Points for Equipment Selection
Selecting the appropriate high current generator is crucial for ensuring accurate and safe testing. The following aspects should be given particular attention:
(1) Core Parameters
Current and Capacity
Select based on the maximum test current requirement of the equipment under test, and reserve a certain margin. At the same time, pay attention to the equipment capacity (kVA), as the capacity determines the equipment’s ability to overcome circuit impedance. Insufficient capacity will prevent the current from reaching the rated value, especially when the test leads are long and the contact resistance is high.
Structure and Power Supply
Choose the structural form based on the application scenario: the integrated type is portable and suitable for variable on-site conditions; the split type is more complex to move but has lighter individual components, making it easier to handle. Also, confirm that the equipment power supply voltage (220V or 380V) matches the on-site power supply conditions.
(2) Performance and Function
Accuracy and Waveform
When high test requirements are involved, choose equipment with an accuracy better than 1.0 grade and a true RMS measurement function to ensure data accuracy. For tests that simulate real grid conditions, select equipment that outputs a standard sinusoidal wave with a small ripple coefficient (e.g., <1.0%).
Regulation and Control
Prefer equipment with stepless smooth regulation to avoid current step changes caused by traditional tap regulation. The equipment should be equipped with safety features such as overcurrent and overvoltage protection.
(3) Key Considerations
Operating Mode
Most high current generators are designed for short-term operation, such as continuous operation at the rated current for ≤ 5 minutes. When selecting and operating, strictly follow the operating cycle requirements, such as cooling for 10-15 minutes after 5 minutes of operation. Do not run at full load for long periods to prevent equipment damage due to overheating.
Wires and Grounding
Pay attention to the cross-sectional area of the test leads and ensure proper grounding to prevent equipment damage and ensure safety. The connecting wires between the equipment and the test sample should have a large enough cross-sectional area, which can be selected based on a current density of 6-8A/mm². The length of the wires should be as short as possible to reduce line loss. The equipment casing must be reliably grounded to ensure operational safety.
Post time: Mar-30-2026