Direct Matrix Converter Topologies with Model Predictive Current Control Applied as Power Interfaces in AC, DC, and Hybrid Microgrids in Islanded and Grid-Connected Modes

Abstract

This paper presents an analysis of a new application of different direct matrix converter topologies used as power interfaces in AC, DC, and hybrid microgrids, with model predictive current control. Such a combination of a converter and control strategy leads to a high power quality microgrid voltage, even with a low power quality main grid voltage and even during the connection and disconnection of a variety of loads and generation sources to the microgrids. These robust systems are suitable for applications in which sensitive loads are to be supplied and these loads are connected close to distributed-generation sources with inherent intermittent behavior. The authors also propose the use of new direct matrix converter configurations with a reduced number of switches in order to achieve reduced cost, reduced failure rate, and higher reliability, which are very desirable in microgrids. Finally, the authors also introduce new hybrid direct matrix converter topologies that provide interesting options for the islanded operation of the microgrids with the use of a battery system. In other words, the proposed hybrid direct matrix converters result in flexible hybrid microgrid configurations integrating DC and AC devices with high power quality and high power supply reliability.

Reactive Power Transfer via Matrix Converter Controlled by the “One Periodical” Algorithm

“…Since, for the 6 × 6 MC, the input voltage after transformation consists only of elements in positions [2] and [6] (Equation (3)), only a single equation has to be considered. The solutions of equations from positions [2] and [6] are conjugated:…”

“…The transformation sequence can start up at the arbitrary phase with relation to the input waveform; thus, the angle φ k was introduced. At the end, the waveforms representing K S [2,2] for inputs voltage positive sequence, for first harmonic and for different frequencies at the input and output can be derived by simulation ( Figure 3).…”

“…After this assumption, for positive sequence and limitation of the divagations to the first harmonic only, the element [2,2] of matrix K S can be then expressed as:…”

“…The harmonic content (especially their order) was then limited similar to multilevel converters. PWM-based methods were not used [1][2][3][4][5].…”

Stochastic Control for Intra-Region Probability Maximization of Multi-Machine Power Systems Based on the Quasi-Generalized Hamiltonian Theory

“…In the power systems, there are many new researches on the power systems control [21][22][23][24][25], but the influence of random factors was not considered. For a power system under the influence of stochastic factors, some analyses were done based on the stochastic averaging method [1,3,14,15,26,27], but the design of the controller was not involved.…”