61 Frequency Converters SFAVM provides a link between the control system and the power circuit of the inverter. The modulation is synchronous to the control frequency of the controller and asynchronous to the fundamental frequency of the motor voltage. Synchronisation between control and modulation is an advantage for high- power control (for example, voltage vector, or fl ux vector control), since the control system can control the voltage vector directly and without limitations. Amplitude, angle and angular speed are controllable. In order to dramatically reduce the on-line calculation time, the voltage values for diff erent angles are listed in a table. Fig.
2.17 Output voltage (motor) – (phase-phase) shows the motor voltage at full speed. Fig. 2.17 Output voltage (motor) – (phase-phase).