This paper analyzes the risk of inadvertent energization fault and problems of inadvertent energization protection during commission and operation, i.e. mal-operation of inadvertent energization protection during generator operation; the duration of fault lasts too long and results in burning loss of generator. Based on the analysis, a solution of inadvertent energization protection with faster speed and better reliability is proposed, which is used for generators in standstill status or jigger status. To avoid mal-operation, this solution uses redundant blocking conditions:voltage blocking and binary input blocking. To trip faster, the solution uses RMS algorithm for voltage and current calculation. This paper describes the logic, algorithm and simulation of Siemens inadvertent energization protection, and demonstrates the advantages of this solution in standstill or jigger status of generators.