Selective Harmonic Elimination PWM with Digital Control Implementation

In power electronics engineering, Selective Harmonic Elimination PWM (SHE-PWM) represents an advanced digital control technique widely employed in controlled AC motor drives and various power applications. This methodology effectively reduces harmonic noise in electrical machines and systems while enhancing overall operational efficiency. The SHE-PWM technology utilizes computational algorithms to determine optimal switching states during each PWM cycle, specifically targeting the elimination of predetermined harmonic components. Implementation typically involves solving nonlinear transcendental equations through numerical methods like Newton-Raphson iteration or optimization algorithms to calculate precise switching angles. Key advantages include exceptionally low harmonic distortion, high efficiency, and precise waveform control capabilities. The algorithm flow generally involves: harmonic spectrum analysis, switching angle calculation, real-time PWM signal generation, and closed-loop validation through MATLAB/Simulink simulations or embedded DSP code execution.