Harmonic cancellation of modern switch-mode power supply load

Abstract

Switch-mode power supplies (SMPS) are one of the most common category of loads, typically found in large numbers in modern power supply systems. These devices usually draw non-linear current and are, therefore, significant sources of harmonics. Although it is well known that the presence of harmonics will result in negative effects (e.g. higher thermal stresses and overloading, or increased neutral conductor currents), the assessment of the actual harmonic levels is not a simple task.