A Scheme of Adaptive Protection System for High-voltage Power Grid of Coal Mine Underground Based on Independent Substatio

To solve the problem of frequent over-grade trip of fast short-circuit protection in high voltage power supply system of coal mine underground,a scheme of adaptive protection system based on independent substation was proposed.By means of real-time monitoring and analysis on voltage and current of each transmission line,the setting value and characteristic of relay protection are automatically adjusted to enhance sensitivity and reliability of overcurrent protection device.By mean of independent substation,longitudinal selectivity of fast short-circuit protection is implemented.The scheme provides technical support to eliminate the potential safety hazard of over-grade trip caused by short-circuit fault that exists in mine high-voltage power grid for a long time.