Low-voltage inverse-time leakage protection method

The invention discloses a low-voltage inverse-time leakage protection method. The method comprises the steps that whether or not a system is in a leakage state is judged by looking up a table on the basis of the system voltage level and the leakage resistance value; if the system is in the leakage state, the inverse time process is conducted, the inverse time delay time of the current leakage resistance is obtained by looking up the table, and if the inverse time delay time is up, an action is executed; and if the system is in a non-leakage state, the inverse time process cannot be conducted,and measurement on the ground insulation resistance is conducted by combining an additional DC power supply method to achieve low-voltage inverse-time protection, wherein measurement on the ground insulation resistance through the additional DC power supply method is achieved by an additional +44V DC power supply generation circuit, an insulation resistance measurement bridge circuit and an insulation resistance measureme