The core solution for mining transformer undervoltage is to locate the root cause first, then take targeted measures such as adjusting voltage, optimizing load or upgrading equipment.

　　Step 1: Identify the Cause of Undervoltage

　　Check the power supply side: Confirm if the incoming line voltage of the transformer is lower than the rated value (e.g., grid voltage fluctuation, longdistance power transmission voltage drop).

　　Inspect the transformer itself: Check for internal faults like tap changer contact poor, winding insulation degradation, or oil quality deterioration affecting output.

　　Analyze the load side: Determine if the load exceeds the transformer’s rated capacity (overload), or if there are large starting currents from mining equipment (e.g., crushers, pumps) causing voltage sag.

　　Check the wiring: Look for loose connections, excessive line resistance (e.g., undersized cables, long wiring distance) leading to voltage loss.

　　Step 2: Targeted Handling Measures

　　Adjust the tap changer: For gridside voltage drop, use the transformer’s onload or offload tap changer to raise the output voltage (follow operating procedures to avoid arcing).

　　Optimize load distribution: Reduce overload by shutting down nonessential equipment, or stagger the startup time of highpower devices to avoid simultaneous large currents.

　　Improve wiring conditions: Replace undersized cables, tighten loose terminals, and shorten the wiring distance between the transformer and heavyload equipment to reduce resistance.

　　Maintain the transformer: Replace aged transformer oil, repair faulty tap changers, and test winding insulation to restore the transformer’s normal working state.

　　Install auxiliary equipment: For frequent voltage fluctuations, add a voltage stabilizer or reactive power compensation device (e.g., capacitor bank) to stabilize the output voltage.

　　Step 3: Safety Precautions for Mining Scenarios

　　All operations must be performed after power failure and grounding to avoid electric shock (mining environments have high humidity and flammable dust risks).

　　Regularly monitor voltage and load with monitoring instruments to detect undervoltage early and prevent equipment damage.

　　Comply with mining electrical safety standards, and prohibit overloading the transformer for a long time to avoid insulation aging or fire.