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 SUPPORT BONDS RIGIDITY INFLUENCES ON THE CARRYING CAPACITY REDUCTION OF THE SHALLOW SHELLS ON A RECTANGULAR PLAN

The coatings construction of buildings and structures in the form of wooden shallow shells on a rectangular plan are considered. The orthotropic of the material and the geometric nonlinearity of the thin-walled structure taken into account in the equations. The Bubnov-Galerkin method is used to solve differential equations of wooden shallow shells with different supports. The influences of the ratio of elasticity in mutually perpendicular directions, shape and thickness of a structure on the value of stresses, critical load and low frequencies of small values of vibrations are investigated. The investigations results are given in dimensionless form and graphs are shown. This makes them useful in engineering calculations. Recommendations for adjusting the shape and thickness of the structure of coatings in the form of shallow shells to increase their bearing capacity or reduce material consumption are given.