Random modulations are treated as one of the solutions for reducing conducted electromagnetic interference (EMI) in power electronics inverters. Although in papers related to inverters, this view has not been clearly demonstrated. Especially in the state-of-the-art papers related to randomly modulated inverters, it is hard to find information about EMI measurement procedures or deeper EMC analyses. Therefore, this paper will discuss the influence of random modulations used in power electronic inverters on selected issues related to inverter EMC and power quality. A complete case study is carried out on a three-phase inverter. The undertaken analysis refers to the generation of interference, EMI measurement methodology, the conditioning of EMI filtration, and the quality of output voltage. The results show which EMI parameters are improved and which parameters are aggravated, when random modulation is used. The presented results show that random modulation should be applied in inverters with great caution. In addition, we show the limitations of EMI measurement methods and propose a more reliable way to assess the EMI spectrum.

Reliable operation of the smart grid requires assurance of the electromagnetic compatibility of sensitive smart metering systems and power electronic converters, which introduce high-level electromagnetic interference. As it has been experimentally shown, currently available, normalized, and frequency domain tests are ineffective for the evaluation of data transmission error hazards. The mathematical time-domain model proposed in this paper enables assessment of the probability of errors occurring in a given transmission signal for known interference parameters. The validity of the model and its practical applicability have been experimentally verified.

Field-Programmable Gate Array (FPGA) provides the possibility to design new “electromagnetic compatibility (EMC) friendly” control techniques for power electronic converters. Such control techniques use pseudo-random modulators (RanM) to control the converter switches. However, some issues connected with the FPGA-based design of RanM, such as matching the range of fixed-point numbers, might be challenging. The modern programming tools, such as LabVIEW, may facilitate the design process, but there are still fixed-point operations and limitations in arithmetic operations. This paper presents the design insights on the FPGA-based EMC friendly control system for DC/DC converter. Probability density functions (PDF) are used to analyse and improve pseudo-random algorithms. The theoretical algorithms, hardware details and experimental results are presented and discussed in terms of conducted electromagnetic interference emission.

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 impact of spread-spectrum techniques used to mitigate EMI from power converters on Power Line Communication (PLC) systems is studied in this paper. A buck converter, utilizing a Random Carrier Frequency Modulation with Fixed Duty cycle (RCFMFD) based control is considered as a source of conducted EMI and a narrowband G3-PLC as the victim. It is shown that, although considered to be an EMI mitigating technique, the spread spectrum technique has a detrimental effect on the communication channel, which can be explained in the framework of Shannon’s information theory. Conventional emission evaluation methods are therefore incompatible with modern day’s technology.

Cyber-Physical Power Systems integrate the various devices which provide ancillary system services. In this paper, the design and implementation of a fully controllable cyber-physical system is presented. This system simulates the behavior of the real power system and additionally assures controllable, repeatable testing conditions, enabling investigations of energy storage systems. Ancillary system services provided by energy storages are especially crucial in the context of renewable energy sources and electromobility sector development. Credible tests of control strategies, realizing system services, require controllability of test parameters. Such investigations are impossible in a real power system, due to its inherent variability. The novel approach presented in the paper enables management of power system resources supplied by various producers and ensures flexibility in the realization of assumed scenarios of power system operation. Such an controllable cyber-physical power system constitutes a suitable environment for tests of the effectiveness of ancillary services provided by energy storage systems, because the system is independent of inherent variability of the real power system and enables flexible realization of the control algorithms developed for all of the system components (power source, loads and energy storages). The voltage profile improvement in low voltage grids has been shown in a case study confirming the applicability of the proposed approach.