Abstract: The protection system of station AC power supply is crucial to the power supply reliability of electrical equipment. Unreasonable protection configuration and setting mismatch may lead to accident escalation, affecting the power supply of the entire station. This paper analyzes the current protection configuration of station AC power supply systems, identifies issues such as difficulties in coordination of setting values and room for optimization in the operating time of overcurrent protection. An optimized configuration scheme for inverse-time overcurrent protection in station AC power supply systems is proposed, which uses voltage coefficients to modify the inverse-time overcurrent protection. This approach simplifies setting value coordination while improving the speed and reliability of station AC power supply system protection, providing valuable reference for field operators.