Power Transformer Testing & Commissioning – Ensuring Reliability from Day One
A power transformer is the single most critical asset in any substation or transmission network. Our goal is to detect and eliminate potential issues before energization, ensuring compliance with IS, IEC, and CEA standards.
Why Transformer Testing Before Commissioning is Critical
Early Fault Detection
Identify winding insulation defects, core faults, or oil contamination before failure
Safety Compliance
Adhere to statutory requirements under Indian Electricity Rules and CEA guidelines
Performance Validation
Verify efficiency, no-load and load losses, and operational readiness
Asset Protection
Avoid catastrophic failures that can cause multi-crore losses and long outages
Our Power Transformer Testing Process
Comprehensive testing from pre-installation inspection to final commissioning and load trials.
1. Pre-Installation Inspection
Before the transformer is placed on its foundation:
- Visual Checks: Inspect bushings, tank, radiators, conservator, and accessories for transport damage
- Nameplate Verification: Cross-check all ratings and specifications against the purchase order
- Accessory Check: Confirm presence and integrity of OLTC, cooling fans, temperature gauges, etc.
2. Electrical Testing
Complete suite of electrical diagnostic tests as per IS 2026, IS 1180, IEC 60076:
Insulation Resistance (IR) & PI
Measures insulation health and detects moisture/contaminationTransformer Turns Ratio (TTR)
Confirms correct ratio between primary and secondary windingsWinding Resistance (WRM)
Detects loose connections, shorted turns, or conductor damageMagnetic Balance Test
Checks core integrity and magnetic path balanceVector Group Verification
Confirms correct phase displacement and winding configurationTan Delta & Capacitance
Measures dielectric loss, indicating insulation conditionShort Circuit Impedance
Validates mechanical integrity and winding design complianceNo-Load & Load Loss
Quantifies core losses and copper losses under loadFrequency Response (FRA)
Detects winding movement or core displacement (for EHV transformers)3. Transformer Oil Testing
NABL-accredited laboratory analysis and on-site rapid tests:
- Breakdown Voltage (BDV): Measures dielectric strength
- Moisture Content (PPM): High moisture degrades insulation
- Dissolved Gas Analysis (DGA): Detects gases indicating electrical or thermal faults
- Furan Analysis: Measures paper insulation degradation
- Acidity & Resistivity: Assess oil aging
If results are outside safe limits, we provide oil filtration, dehydration, or regeneration.
4. Functional & Protection System Testing
- OLTC Operation Check: Verifying tap changer functionality under no-load conditions
- Cooling System Check: Testing fans, pumps, radiators, and temperature controls
- Protection Relay Testing: Overcurrent, differential, and Buchholz relay trip checks
- SCADA & Communication: Ensuring transformer parameters are visible in control rooms
5. Commissioning & Load Trials
Energization Under No-Load:
Initial energization to check for abnormal sounds, vibrations, or temperature rise.
Load Trials:
Gradually loading transformer to operational capacity, monitoring all parameters.
Case Example
160 MVA Transformer Commissioning Success Story
160 MVA Transformer
Tamil Nadu State Transmission Utility - 2024
Project Highlights
Specifications: 160 MVA, 220/132 kV power transformer for state transmission utility.
Challenge: Tight commissioning schedule before monsoon season.
Solution: Parallel execution of oil filtration and electrical testing teams.
5 Days
Ahead of schedule energization
Zero Defects
In acceptance testing
Safety & Compliance Standards We Follow
Indian Standards
IS 2026, IS 1180, IS 10028
International Standards
IEC 60076, IEEE C57.12
Electrical Safety
Strict PPE usage, lockout/tagout, and earth discharge protocols
Industry Trends in Transformer Testing
Adopting latest technologies for enhanced testing and monitoring
Online Monitoring
IoT-enabled sensors for continuous health tracking
Digital Twin Simulation
Virtual commissioning before physical energization
Vacuum Oil Treatment
Enhanced filtration for extended transformer life
Condition-Based Maintenance
Moving from time-based to predictive maintenance