In order to solve the problem of poor power quality in complex working conditions underground coal mines, research is conducted on the detection and compensation methods for abnormal currents. Detailed analysis was conducted on the structural principles and functional characteristics of various types of second-order generalized integrators, achieving precise tracking of current and efficient filtering. Further propose a current comprehensive compensation method based on a second-order generalized integrator structure to implement fundamental frequency filtering. The symmetrical component method is used to extract the current positive sequence component, and the instantaneous power theory is used to extract the current active component. Then, the fundamental frequency positive sequence active component in the load current is uniformly obtained, and the difference between the actual load current and this component is taken as the sum of the components that need to be compensated, achieving comprehensive detection and compensation of the current. Based on the Simulink platform, simulation experiments were conducted on the compensation effect under various non ideal load conditions to verify the accuracy of theoretical analysis. The results showed that this method can achieve comprehensive detection and compensation of abnormal currents such as reactive power, harmonics, and imbalance, and is feasible for power quality control in complex working conditions underground coal mines.