Direct current control method for three-phase motor drives

The requirements of three-phase motor drives in terms of reliability, efficiency, robustness, dynamic as well as cost efficiency are continuously increasing within the last years. To meet this demand the hardware components and motor drives are used in non-linear and special operating points leading to increased requirements for the control method. This paper presents a new direct current control method that is able to work at these operating points. It is robust, able to deal with non-linear loads and that overcomes some disadvantages of existing direct current control methods. The generic approach would even allow to use inverter systems with more than two levels.