As the core equipment of the power system, the electrical performance of transformers is tested and evaluated throughout the entire life cycle of manufacturing, installation, operation, and maintenance. With the continuous improvement of industry requirements for testing efficiency and accuracy, the comprehensive equipment specifically designed for transformer testing – the transformer comprehensive tester and the transformer comprehensive test bench – have become standard tools in the field of power testing. Although both types of equipment can cover core testing indicators such as transformation ratio, direct resistance, and no-load loss, they have essential differences in product form, integration degree, and applicable scenarios. The rational selection of equipment directly affects the efficiency and quality of the testing work.
Equipment Definition and Technical Positioning
The transformer comprehensive tester is a portable and highly integrated precision measuring instrument that integrates the scattered testing projects of traditional multiple independent instruments to achieve multi-parameter integrated testing.
The typical characteristics of the equipment are small size and most weights are within the range of 3-20 kilograms. It can be equipped with batteries or small test power supplies and can be directly carried to the work site for operation. Some models of the equipment can complete parameter tests such as capacity, no-load current, and short-circuit loss for transformers in the range of 20kVA to 100,000kVA.
The transformer comprehensive test bench belongs to a complete fixed system, generally consisting of control cabinets, operation consoles, power cabinets, voltage regulators, and other components. The overall volume of the equipment is large, and the weight can reach several hundred kilograms or even higher. It needs to be fixedly installed for use.
The entire system integrates measurement, control, power supply, and protection functions modules, and comes with a power unit that meets the conditions for high-power tests, including voltage regulators, intermediate frequency units, and other components. It has a complete set of capabilities such as test wiring display, data acquisition and analysis, measurement control, data storage and printing, and safety protection. The entire test process can run automatically.
Typical Application Scenario Analysis
Comprehensive Tester: A Versatile Tool for On-site Operations
Portability and flexibility are the core advantages of the comprehensive tester.
In the transformer capacity verification work, some power users have tampered with the nameplate of the transformer, and inspection staff need to carry the equipment to the site to verify the actual capacity of the operating transformer. Portable comprehensive testers are suitable for such on-site operations. Some models are equipped with large-capacity rechargeable batteries, which can complete hundreds of measurements for multiple devices with a single charge, without the need to additionally configure three-phase test power supplies, voltage regulators, and current boosters, etc. The wiring operation is simple, effectively improving on-site operation efficiency.
The handover tests, preventive tests, equipment fault investigations in substations and wind farms, as well as the sampling tests of different specifications of transformers in research laboratories, all rely heavily on its portability. Some integrated portable models can perform tests such as DC resistance, turns ratio, insulation, and absorption ratio for transformers up to 220kV and below, suitable for railway traction power supply and on-site maintenance and repair scenarios of power transformers.
Comprehensive Test Bench: A Workstation for Factory Batch Testing
The core advantage of the comprehensive test bench is efficiency and high automation.
Before each product leaves the factory, the transformer manufacturer needs to complete a full set of electrical tests such as no-load loss, load loss, transformation ratio, DC resistance, withstand voltage, and induction withstand voltage. If using a single instrument for each test, the staff needs to repeatedly change the wiring and replace the testing equipment, resulting in low efficiency and prone to human errors.
The comprehensive test bench supports connecting the lines once and starting all test items at once. It relies on software to automatically execute the tests according to the process, automatically complete data acquisition, storage, and output standardized test reports, avoiding errors caused by manual data copying, and significantly improving the factory testing efficiency.
These types of equipment can cover all test projects of transformers of various capacities and voltage levels and are suitable for the detection requirements of large-scale and multi-specification products.
For the tests of large transformers of 110kV and above, it is necessary to combine indicators such as temperature rise test and large active power, and to equip with voltage regulators, intermediate transformers, capacitor compensation devices, transformers, etc. as a complete set of components. Such large-scale test systems are the extension and expansion of the integrated test platform system, still adhering to the core design concept of integration and automation.
Recommendations for selection decisions
Priority selection scenario for comprehensive test instruments
The power operation and maintenance department needs to conduct preventive tests and equipment fault diagnosis at various substations and distribution sites;
The electricity inspection-related units need to verify the actual capacity and energy efficiency grade of transformers on-site;
The engineering debugging units need to carry out operations among multiple project sites;
The research laboratory needs to flexibly complete the random inspection tasks of transformers of different voltage levels and specifications.
Priority selection scenario for comprehensive test platforms
Transformer manufacturing enterprises need to conduct complete factory tests on multiple products every day;
Large-scale power maintenance centers need to conduct standardized type tests for returned-for-repair transformers;
Fixed testing sites need to meet strict requirements for the standardization of test reports and data traceability.
These two types of equipment do not have an either-or opposition relationship. Large transformer manufacturing enterprises often configure comprehensive test platforms for batch factory tests, while also equipping portable test instruments for on-site service work after sales; Power maintenance centers can also configure comprehensive test platforms to meet centralized maintenance tests, and provide portable test instruments to front-line teams for external on-site inspections. The key to selection is to make the equipment performance match the actual business scenarios, rather than simply judging the quality of the equipment.
Post time: Sep-15-2026