Novel modified phase‐shift modulation strategy for isolated AC–DC power converters

Abstract

Different power converter topologies are used to perform the energy exchange between an AC grid and a DC source belonging to a hybrid electric micro-grid. A single-phase single-stage isolated AC-DC power converter is one of them. Moreover, this power converter can operate under different modulation strategies. The phase-shift modulation (PSM) strategy is capable of varying the phase between the voltages applied to the high-frequency transformer terminals of the power converter in order to control the energy flow in both directions. Based on the PSM strategy, this study presents a novel modified PSM strategy capable of controlling the power flow in both directions and obtaining a current with low total harmonic distortion and a power factor close to 1 for the entire operating range on the AC side. Considering the novel modulation strategy to be proposed, a comparison of three PSM-based modulation strategies was carried out taking into account the total harmonic distortion of current injected into the AC grid, the power factor and the average power transferred. A theoretical analysis was carried out and the results obtained were validated by means of experimental results.

High performance single stage power factor correction circuit

“…Although the structure is very good but tight output regulation is not achieved since the power is not processed twice and also the structure is non‐isolated. In [31, 32] two new structures are introduced which are proper for high power applications. The structure introduced in [33] is proper for high power multi string LED driver when isolation is not necessary.…”

Research and Simulation of DC Microgrid Three-Phase AC-DC Converter Control Strategy Based on Double Loop

“…How to suppress the fluctuation of the bus voltage of the DC microgrid to ensure the stable operation of the system is one of the hot issues in the field of DC microgrid research. When the DC microgrid is connected to the AC power grid, the control of the bus voltage is often achieved by optimizing the control system of the DC microgrid threephase AC-DC bidirectional converter [6][7][8].However, the loads carried by the three-phase AC-DC bidirectional converter of the DC microgrid are usually complicated and changeable, that is, the external interferences are timevarying. Some parameters on the AC side of the converter, such as the equivalent resistance and inductance of the line, cannot be accurately measured.…”