By hvhipot 
Core Components
A typical Transformer Test System usually consists of the following parts:
1.Main Control System (The Brain):
An industrial computer or high-performance embedded system, equipped with professional testing software.
Responsible for controlling all test units, data acquisition, processing and analysis, report generation, and human-computer interaction.
2.Multi-Function Test Units (The Limbs):
Turns Ratio Test Unit: Precisely measures the transformer’s turns ratio and vector group (connection group).
Winding Resistance Test Unit (DC Resistance): Measures the DC resistance of winding coils to check for proper conductor connections, solder joints, and tap changer contact.
Winding Deformation Test Unit (Optional): Determines if windings have shifted or deformed mechanically using Frequency Response Analysis (FRA).
Insulation Characteristics Test Unit: Includes Insulation Resistance and Dielectric Absorption Ratio/Polarization Index testing to evaluate the insulation condition between windings and between windings and ground.
Dielectric Withstand Test Unit: Performs Power Frequency AC Withstand and Induced Voltage tests to assess the strength of the main and longitudinal insulation.
No-Load Loss & No-Load Current Test Unit: Measures losses and current under rated voltage on one side of the transformer with the other side open-circuited.
Load Loss & Impedance Voltage Test Unit: Measures losses and voltage under rated current on one side of the transformer with the other side short-circuited.
Temperature Rise Test Unit (For Large Benches): Simulates the temperature rise of a transformer under long-term operating conditions.
3.Switching and Protection System (The Nervous System):
Comprises relay arrays, programmable switches, etc., to automatically switch test circuits and ranges.
Includes protection circuits (overcurrent, overvoltage, discharge, etc.) to ensure the safety of the testing process and the equipment.
4.Auxiliary Systems:
High-precision standard instrument transformers (CTs/PTs), test fixtures, connection leads, printers, etc.