Practical issues of implementation improved spectrum output voltage in power switched-mode generators

The paper presents the ways of improving output voltage spectrum in switched-mode generators. Because of errors arising while setting the transistors' switching times, it is rather difficult to achieve the required compensation of higher harmonics. Switching times errors are caused by the inertia of the switching process in power transistors as well as sampling errors of control devices. Analysis has shown that error of 2–3 deg. in multilevel voltage leads to an increase of higher harmonics to the level −38 … −42 dB. This problem can be solved by introducing an amendment of control pulses time position enabling to decrease these errors. The optimal values of the sampling frequency enabling to achieve effective compensation of higher harmonics are provided.