ANALYSIS THE EFFECTIVENESS OF SPREAD SPECTRUM TECHNOLOGY TO REDUCE THE LEVEL OF DC/DC CONVERTERS CONDUCTED INTERFERENCE
Abstract
Switch mode power supplies (SMPS) generated a wide range of conductive and inductive interference. Moreover, the spectrum dominated by discrete components with a switching frequency of a power
transistor and its harmonics. The spectrum width can reach several tens of megahertz. Known technology
Spread Spectrum, widely used in communication systems, allows expanding the spectrum of the signal, reducing the level of its components to the noise.
The aim of this work is to study the effectiveness of technology use Spread Spectrum to reduce conductive interference when operating DC/DC converters, search methods, modulation parameters of the modulated signals.
For the research was the simulation of a step-down DC/DC Converter in the program NI Multisim. The
efficacy of reducing the level of conducted interference estimated by comparing the spectra of the current
given by a power supply Converter operating in various modes: with a fixed conversion frequency and time
varying.
The results of modeling in NI Multisim confirmed the high efficiency of this technology. Discrete components of the spectrum are blurred in a wide range of frequencies and the level of conducted interference
can be lowered by 15...16 dB. Studies have shown that the most effective application for reducing interference using frequency modulation control signal according to a triangular law. The article presents recommendations for selecting the frequency of the modulating signal and the frequency deviation of the modulated oscillations to obtain the maximum of useful effect.