Power Transformer Testing
Diagnosis, Maintenance, and Reliability for Critical Power Grid Equipment
Power transformers play a fundamental role in the transmission and distribution of electricity, enabling the interconnection between different voltage levels across the power system. Their main function is to adjust voltage and current levels, allowing integration of power plants, substations, transmission lines, and load centers.
Given their strategic role in the grid, preventive and predictive maintenance of these assets is essential to avoid failures, extend equipment lifespan, and ensure a stable energy supply. In this context, periodic electrical testing is a crucial practice, both for diagnostics and for validation during commissioning or after maintenance.
Importance of Power Transformer Testing
Power transformers are subject to various types of stress, such as:
Transient and permanent overvoltages;
Inrush currents;
Thermal and mechanical stresses;
Harsh environmental conditions;
Natural degradation of insulating materials.
These conditions can directly affect equipment performance and lead to catastrophic failures. Therefore, standardized electrical tests, according to IEC, IEEE, and ABNT standards, are essential to assess transformer condition and anticipate corrective maintenance actions.
Conproveโs Solution for Transformer Testing
To provide a complete solution for primary and secondary equipment testing, Conprove has developed the CE-7012, a robust and versatile universal tester capable of performing a wide range of tests on power transformers with accuracy, safety, and ease. Using the CTC โ Conprove Test Center software platform, users can automate tests, generate reports, and store results efficiently.
Key tests include:
Single-Phase Turns Ratio Test
Verifies the transformation ratio between high and low voltage windings, identifying deviations, inter-turn short circuits, and insulation failures. It also measures the angular phase shift, a key parameter for performance analysis.
Three-Phase Turns Ratio Test
Allows testing of three-phase transformers with Y-Y, ฮ-ฮ, Y-ฮ, ฮ-Y, and other configurations. With Conprove software, tap changer positions (OLTC) can be tested automatically.
Winding Resistance Measurement
Measures the resistance of each winding to detect loose connections, internal shorts, or contact wear on taps. It also helps identify thermal imbalances and conductor aging.
Insulation Withstand Voltage Test
Applies 2 kVac between terminals and ground to identify insulation failures, cracks, moisture, and other defects that could lead to shorts or transformer breakdown.
Recommended Equipment
CE-7012 โ Universal multifunction tester for protection and automation equipment (secondary level) and power transformers (primary level). Robust, portable, and highly reliable. CTC โ Conprove Test Center: Software platform that integrates all Conprove equipment features, with a user-friendly interface and graphical analysis tools.
Field and Laboratory Applications
The Conprove transformer testing line is used by:
Power utilities;
Maintenance and electrical engineering companies;
Industries with in-house power systems;
Electrical and metrology laboratories;
Transformer manufacturers.
Thanks to the equipmentโs portability and the flexibility of the CTC software, testing can be performed both in laboratories and directly in the field, delivering reliable results in accordance with major international standards.
