Signal-to-noise ratio in power electronic digital control circuits

This article presents selected aspects relating to digital signal processing in digital control circuits in power electronics. The following typical problems are discussed in this paper: signal sampling rate (phenomena of aliasing, synchronization) coherent sampling, jitter of sampling pulse, sequential vs. simultaneous sampling in a multichannel system, signal resolution (signal-to-noise ratio, noise shaping circuit, changing of sampling speed) interpolation and decimation, and conversion of analog circuits to digital form. In this paper a new formula for calculation of the resultant signal-to-noise ratio for three stages digital control circuit is presented. Consideration of these sources of error and their subsequent correction allows for a greater signal-to-noise ratio and minimization of distortion components, which in turn results in improved parameters of output/input currents and voltages, which can further affect the quality of energy processing in power electronic circuits.