Abstract: Abstract：Coal is one of the power of social construction and development of the main energy source, but the problem of coal mine safety can not be ignored. The analysis shows that coal mine accidents in recent years, the voltage stability has become one of the factors that threaten the safe operation of coal mine, so to solve this problem is to brook no delay. Using the electric spring adjustable voltage amplitude characteristic, can ensure the voltage stability of electric equipment in need of protection, so the voltage quality needs strict power equipment can safely and effectively under the rated voltage of the work, so as to provide a reliable guarantee for the safety production of coal mine.

Key words: Keywords：electric spring, coal, voltage stability, MATLAB