| Abstract |
The algorithms of nonstandard pulse-width-code modulation, which provides smooth shockless inverter ratio changing, have been considered. This comparatively simple and easy digitisation control principle is based on the continuously step-by-step coding (identification) the widths of pulses and pauses of output voltage formed at clock points with the one of the main range of output pulses, connected directly with the output frequency. The basic methods of the pulse-width-code modulation for three-phase thyristor inverters with control both inside and in border of clock intervals have been developped for the standard and nonstandard performance modes. The analytical description of the rational control laws for ac inverter drives has been done for the instances when average frequency of inverter with commutation vary according to different linear and nonlinear correlations. The analysis of the harmonic composition of the various versions of inverter output voltage has been carried out and technique of its improvement has been considered. |
