A novel algorithm in solving nonlinear equations for programmed PWM inverter to eliminate harmonics

The preprogrammed PWM inverters eliminate low-order harmonies by optimizing the switching angles. In this paper a novel method for solving nonlinear equations in preprogrammed PWM Inverters is presented. The starting values for solving the nonlinear equation, are derived from the equal area algorithm. This method guarantees convergence in a numerical solution for solving nonlinear equations so that the trial-and-error processes can be significantly reduced. The numerical solutions for nonlinear equations for a full range of the fundamental amplitude can be easily obtained. Thus, this method makes fundamental amplitude modulation feasible and is helpful for online control. The output pattern of the proposed programmed PWM technique is superior to the equal area algorithm in harmonic attenuation since this technique eliminates the specified harmonics. The experimental results are used to verify the performance of the proposed scheme.