부산대학교 도서관

To cut down switching losses, the low switching frequency pulse width modulation (LSF-PWM) approach is preferred for medium voltage and high power applications. The major challenge with these strategies is obtaining the switching instants by solving a series of non linear transcendental equations in entire modulation index range. The number of switching angles employed determines how many harmonics are controlled from the output. Furthermore, across various ranges of modulation index, the system of equations reveals several solutions, no solution, or a single solution. The numerical and algebraic techniques does not provide any solution in modulation index range of beyond 0.9 and therefore restricts the maximum achievable output voltage in the entire range. In this paper, minimization of harmonics based on Imperialist Competitive Algorithm in a three phase two-level voltage source inverter is proposed to obtain the optimum solution in the modulation index range of 0.8 to 1. A DSP controller based hardware implementation of a three phase two-level voltage source inverter designed with intelligent power module (IPM) is provided in the research paper to validate the proposed idea.