IGBT inverter with vector modulation

This work presents the design of a three-phase inverter with Insulated Gate Bipolar Transistors (IGBT's). The pulse width modulation technique based on the space vector theory is analyzed in detail. The modulation strategy considers the calculation of the on-times of the different voltage vectors that must be applied to the load, to generate the voltage vector required by the speed control system of the machine. These times are calculated previously and stored in a ROM, producing a simple, reliable, compact and low cost digital modulator. The inverter behaves as a voltage source with variable amplitude and frequency. By using the space vector theory, the number of commutations in the inverter is minimized, reaching a reduction in the switching frequency and in the current distortion.