To overcome the shortcomings of the conventional SVM for diode clamped multilevel inverter, a classification algorithm based on Kohonen's competitive NN was propsed. Although the algorithm is an NN-based one, it does not need a training stage. The proposed SVM switching strategy eliminates the time consuming operations, so the whole procedure for the implementation of the algorithm is carried out with simple mathematical operations. The validity of mathematical analysis and the feasibility of the proposed algorithm were verified with simulation studies for both a three-level DCI and a five-level DCI. The simulation studies also verify that the proposed algorithm is a generalized one for an n-level DCI and does not need any modification when the number of levels increases.