Space vector modulation (SVM) is widely used in three phase converters. This paper presents a novel SVM algorithm in three phase coordinate system which is very simple to implement. In this algorithm, the role of the zero sequence component in SVM is studied, and the switching states and duty ratios are calculated straightforwardly without vector synthesis. Only one coordinate transformation is needed when the zero sequence component is identified. The algorithm is proved to be applicable for any number of levels by theoretical study and illustrations. Simulation and experimental results are presented to verify the effectiveness of this algorithm.