Computationally effective algebraizated method of feedforward synchronous PWM [invertor applications]

The paper describes developed version of novel frequency-oriented methodology of direct pulse width modulation (PWM) of line-to-line output voltage of three-phase voltage source drive inverters, based on special piece-wise approximation of the function of active switching states from their position inside clock intervals. The method is based on two-stage quasi-sliding scheme of modulation and allows to provide: (a) pure algebraic representation of laws of voltage modulation for high-performance systems; (b) continuous synchronous and symmetrical variation of voltage waveform of inverter during, the whole control range; and (c) simple linear control in the zone of overmodulation. Computational simplicity and effectiveness characterize these DSP-oriented algorithms of digital modulation. It has been given examples of determination of parameters of output voltage of inverter with low switching frequency. It has been presented results of simulation of drive system fed from inverter with the proposed method of PWM.