As power systems demand higher energy efficiency and automation, smart step-up transformers—equipped with online monitoring, automatic voltage regulation, and remote communication functions—have become key assets in modern transmission and distribution networks. To ensure long‑term safe, reliable, and efficient operation, it is essential to implement a scientific routine maintenance plan. Xinhong Electrical, drawing on years of industry experience, outlines the core daily maintenance tasks for smart step-up transformers.
Enclosure & accessories – Check for deformation, cracks, oil leakage, or corrosion on the tank, cooling fins, bushings, conservator, and explosion vent.
Foundation & grounding – Verify no foundation settlement; ensure the ground connection is firm and the grounding resistance meets specified standards.
Surroundings – Remove weeds, combustible materials, and foreign objects near the transformer. Ensure good ventilation and heat dissipation, and keep identification labels clear.
Noise & vibration – Use smart sensors or listen manually to confirm smooth, stable operation without abnormal electromagnetic vibration or discharge sounds.
Smart step-up transformers are typically equipped with oil level gauges, oil temperature sensors, and remote data transmission modules. Daily attention should include:
Oil level – Verify the oil level is within the normal range according to the oil level/temperature curve. A significant drop indicates a need to check for leaks.
Oil temperature – Top oil temperature should generally not exceed 95 °C, and the temperature rise should not exceed 55 °C (depending on insulation class). If the smart system issues an over‑temperature alarm, immediately analyse the load and cooling system status.
Oil quality – Perform dielectric strength, water content, and dissipation factor tests every six months to one year. Shorten this interval if the transformer operates in harsh environments.
Xinhong Electrical smart step-up transformers incorporate an intelligent control cabinet (PLC, data acquisition modules, communication terminals, etc.). Routine maintenance should include:
Data display – Compare local instrument readings with remote data (voltage, current, active/reactive power, frequency, etc.) to ensure consistency.
Alarm function – Trigger a simulated alarm (e.g., over‑temperature, pressure relief valve operation) and confirm that the alarm is correctly uploaded to the monitoring centre.
Automatic voltage regulation mechanism – For transformers with on‑load tap‑changers, regularly check the tap‑change counter and perform manual/remote operation tests to ensure smooth and jam‑free contact switching.
Communication status – Verify that 4G/5G, fibre‑optic, or RS485 communication indicators are normal to ensure uninterrupted remote operation and data collection.
Terminals – Use an infrared thermal imager or spot thermometer to check for overheating at primary/secondary terminals and busbar connections (a temperature difference >10 °C requires immediate attention).
Insulation resistance – During an outage, measure insulation resistance (high to low, high to ground, low to ground) using a 2500 V or 5000 V megger, and record the absorption ratio. Values should not fall below 70 % of factory test results.
Surge arresters and protection devices – Check the operation counter and leakage current of surge arresters. Verify that smart transformer protection settings have not been altered inadvertently.
Fans and oil pumps – Listen for abnormal noise, check vibration and current draw. Remove dust and debris from air ducts and grilles. For forced‑oil forced‑air cooled transformers, periodically switch to standby coolers.
Silica‑gel breather – Observe the colour of the silica gel. Replace or regenerate when more than two‑thirds has turned pink or colourless. Ensure the oil cup contains an adequate oil level to filter moisture.
Smart temperature/humidity controller – Check that cabinet heaters and dehumidifiers operate as set to prevent condensation that could affect secondary circuits.
Xinhong Electrical recommends at least one comprehensive preventive test per year for smart step‑up transformers, including:
Winding DC resistance measurement
Voltage ratio and vector group verification
Dissipation factor and capacitance measurement
Partial discharge test (for voltage ratings of 10 kV and above)
Smart component functional check (protection logic, time synchronisation, event recording, etc.)
For transformers that have been in service for three years or have experienced a short‑circuit fault, additional winding deformation testing (frequency response analysis) should be performed.
Fully utilise the data logging and remote transmission capabilities of the smart step‑up transformer. Where the Xinhong Electrical cloud platform is available, automatically generate daily maintenance reports. During manual patrols, scan the equipment QR code with a mobile terminal to enter inspection results and defect photos; the system will automatically remind you of the next maintenance date. Digital records enable:
Trend analysis of historical oil temperature and load to predict potential failures
Life‑consumption tracking of on‑load tap‑changers
Closed‑loop management of work orders to improve maintenance efficiency
Routine maintenance of a smart step‑up transformer is not merely “walk‑around and cleaning”; it is a process that integrates traditional electrical servicing with smart system diagnostics. Xinhong Electrical continues to provide high‑reliability smart step‑up transformers and full life‑cycle service solutions to customers worldwide. By diligently following the maintenance points above, you will not only extend equipment life but also fully realise the advantages of smart monitoring, automatic voltage regulation, and remote operation – laying a solid foundation for high‑quality power system operation.
For a customised maintenance schedule or technical training, please contact the Xinhong Electrical technical team.
