A　direct　torque　control　(DTC)　method　for　electrically　excited　synchronous　motor　(ESM)　drives　has　been　investigated　in　this　paper.　It　is　based　on　the　compensation　of　the　stator　flux　linkage　vector　error　using　the　space　vector　modulation　to　decrease　the　ripples　in　torque　and　flux　linkage.　In　order　to　increase　the　power　factor　and　load　ability　of　ESMs,　an　optimum　rotor　field　current　control　scheme　has　been　presented,　which　is　suited　well　in　the　whole　speed　range.　In　the　closed　loop　of　the　rotor　current　control,　the　reference　rotor　current　is　directly　calculated　with　the　torque　and　stator　flux　linkage　modulus　references.　Compared　to　the　traditional　DTC　method,　the　results　of　experiments　show　that　the　presented　DTC　has　low　ripples　in　torque　and　flux　linkage,　and　almost　achieves　unity　power　factor.　©2008　IEEE.