Piotr Lezynski

Time-Domain-Based Assessment of Data Transmission Error Probability in Smart Grids With Electromagnetic Interference

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.

Determination of flux density produced by multilevel inverters in CM voltage filter

Purpose – The purpose of this paper is to evaluate the conditions in which a saturation of the common mode (CM) choke might appear to be essential for proper design of the CM voltage filters. This paper presents a method for the determination of a CM choke flux density produced by multilevel inverters with carrier‐based modulations.Design/methodology/approach – The proposed combination of secant and tangent methods allows efficient and high‐resolution determination of the CM voltage waveforms produced at the output of the multilevel inverters with commonly used carrier‐based modulations.Findings – The presented results show that the application of a five‐level inverter with specific modulation causes a decrease of the maximum flux density, down to 15 per cent of the maximum level of the flux density reached in a two‐level inverter. The proposed, dedicated approximation method provides an accuracy of the root estimation better by about three orders for a comparable number of the function calls in compariso...

Zero CM voltage multilevel inverters for smart grid applications

In the paper multilevel inverters with common mode (CM) voltage compensators are recommended as voltage sources that can constitute the main components of the energy balancing systems for end-user customers. These systems are a part of the modern LV and MV smart grids [1-3]. Measurements have been provided from a power system consisting in multilevel inverters and a passive compensator assuring sinusoidal output voltages and zero CM voltage [4]. The presented theoretical analyses and experimental results show that the main application problem with magnetic saturation of the CM choke becomes less important in multilevel inverters with specially selected modulation. This allows a reduction in size, weight and cost of inductive components of compensators in such applications.

CM Voltage Compensators for Power Electronic Interfaces

The experimental results presented in the paper have shown that the application of the PEIs might cause EMC related problems, especially in the case of the application of a group of connected converters. The most convenient way to reduce EMI currents and prevent aggregation of EMI currents introduced by a group of converters is through passive compensation of voltage interference sources inside of the single converters. In the paper the concept of the passive compensation of CM voltage at the output of converters has been verified in an experimental arrangement. The obtained experimental results confirm that the compensation of the CM voltage brings about significant attenuation of the CM currents in load circuits. The presented compensator can be integrated with single DC-DC converters as well as applied at the output of a group of the connected converters.

A new control method of energy conversion for the cascaded voltage source inverter

In the paper a new control method for the five-level cascaded inverter is presented. The proposed control method allows full regulation of energy collection from a particular DC voltage source. Application of the cascaded inverter with the proposed control brings many benefits to the DC/AC energy conversion with several DC sources. These benefits are: reduction of the emission of electromagnetic disturbances, an increase in the efficiency and power quality at the output of the inverter.