A new control strategy related to hysteresis control method for inverters is presented. It permits to form the output wave easily and efficiently by means of PWM. This formation method is based on a new powerful modulation mode. The proposed inverter control scheme allows improvements on the AC drive performances while using simple dedicated hardware. The flexibility gained by the proposed method can achieve easily the self adaptation with minimum switching frequency, and consequently high inverter capability. The proposed scheme would be attractive for recent applications that requires non standard wave forms. In this paper, firstly, a comparison between the known bipolar and unipolar modulation modes is given. The drawbacks of these modulation modes are studied and a modified hysteresis controller is proposed. Then a new hysteresis control structure is presented and tested. It realizes an efficient and powerful modulation method that provides a so called freepolar PWM mode. This mode exhibits the advantages of the bipolar and unipolar modulation modes. The new control method solves the hard dependency of the controlled state on supply voltage and load parameters. Comparisons between different control structures for sinusoidal and non-sinusoidal operations are given. The investigation method considers all practical constraints for the power electronic devices and micro-electronic integrated circuits using PSpice.
| Filename: | Unnamed file |
| Filesize: | 1.213 MB |
