The Effect of EMI Generated from Spread-Spectrum-Modulated SiC-Based Buck Converter on the G3-PLC Channel

Power line communication (PLC) is increasingly emerging as an important communication technology for the smart-grid environment. As PLC systems use the existing infrastructure, they are always exposed to conducted electromagnetic interference (EMI) from switching mode power converters, which need to be tightly controlled to meet EMC regulations and to ensure the proper operation of the PLC system. For this purpose, spread-spectrum modulation (SSM) techniques are widely adopted to decrease the amplitude of the generated EMI from the power converters so as to comply with EMC regulations. In this paper, the influence of a spread-spectrum-modulated SiC-based buck converter on the G3-PLC channel performance is described in terms of channel capacity reduction using the Shannon–Hartley equation. The experimental setup was implemented to emulate a specific coupling path between the power and communication circuits and the channel capacity reduction was evaluated by the Shannon–Hartley equation in several operating scenarios and compared with the measured frame error rate. Based on the obtained results, SSM provides the EMI spectral peak amplitude reduction required to pass the electromagnetic compatibility (EMC) tests, but results in increased EMI-induced channel capacity degradation and increased transmission error rate in PLC systems.

THE INFLUENCE OF PLASTIC STRAINS ON THE BEHAVIOR OF BENDING REINFORCED CONCRETE ELEMENTS WHEN CHANGING THE FORCE SIGN

The Russian standards for earthquake resistant constructions suppose the development of plastic strains in reinforced concrete constructions under seismic effects. Their presence influences significantly on the stress-strain state, bearing capacity and mechanism of destruction of reinforced concrete constructions under alternation loads of high intensity. The methodology and main results of experimental tests connected with the evaluation of plastic deformations influence on the behavior of reinforced concrete bending elements when changing the force sign is represented. The information about the bearing capacity reduction when changing the force sign with the increase of plastic strains in the first semi cycle of loading is given. The coefficients of plasticity for reinforcement deformations limit values are obtained, corresponding to the beginning of compressed zone concrete destruction when changing the force sign and the plots of normal sections deformations distribution of experimental specimens under direct and reverse loading have been built.

The influence of cutouts in slabs of formwork-free molding on their load-bearing capacity

The paper presents the results of testing the slab of formwork-free molding (PB slab) for strength, as well as numerical study of the finite element model of this slab. It is shown that with an angular cutout in the PB slab, its load bearing capacity decreases and the nature of fracture changes. Partial compensation for the load-bearing capacity reduction of the slab with such a cutout can be achieved by reducing the pre-stressing reinforcement value of reinforcement rods cut off during the formation of the cutout, or by redistributing the reinforcement along the cross-section of the slab.