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

Abstract

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.

Electromagnetic Interference of Power Converter with Random Modulation on the Power Line Communication System

“…However, RPWM spreads the noise spectrum, which exhibits higher amplitude than the conventional PWM in the frequency range around 5 kHz (see the black box in Figure 12), with a consequent increase of the interference with the communication signal. This conclusion is in line with the one drawn in Reference [21], where it was proven that RPWM causes more frame error rate than the conventional PWM. However, the RPWM scheme considered in Reference [21] is based on varying the switching frequency of the pulse signal, i.e., the RPWM strategy adopted in that work is different from the one exploited here.…”

“…This conclusion is in line with the one drawn in Reference [21], where it was proven that RPWM causes more frame error rate than the conventional PWM. However, the RPWM scheme considered in Reference [21] is based on varying the switching frequency of the pulse signal, i.e., the RPWM strategy adopted in that work is different from the one exploited here.…”

“…In Reference [20], the effects of power converter modulation scheme on low frequency digital communication systems were studied, and it was proven that RPWM does not have significant effect on digital communication systems. Recently, in Reference [21], the influence of a random modulated SiC-based buck converter on the G3-PLC channel performance is presented, where it was shown that the use of RPWM reduces the channel capacity compared to conventional PWM. However, in that work, only a specific random modulation technique was implemented (i.e., random frequency modulation), and other strategies (such as the random pulse position modulation considered in this work) were not considered.…”

“…Therefore, further investigations are still needed in order to investigate the advantages/disadvantages of different RPWM in power grids involving PLC systems. Moreover, the works of References [18][19][20][21] focus on experimental analysis only, and simulation models combining accurate modeling of both the power and communication parts of the systems still need to be developed. Indeed, although several models of each separate parts of the system are already available, there is a lack of simulation models in which both the power system and the communication system are modeled as a whole.…”

Power Quality Phenomena, Standards, and Proposed Metrics for DC Grids

“…As a consequence, a balanced and comprehensive limitation of emissions in the supraharmonic range is a necessity to allow the smooth operation of PLC technology in modern DC microgrids and smart grids. An effective approach is the adoption of spread-spectrum modulation converters, as shown in [67].…”