Analysis of Novel Energy-Efficient Converters to Ensure the Required Quality of Electrical Energy

Abstract

This article proposes several solutions for the use of novel AC voltage regulators as electrical energy quality conditioners and for the use of a half-bridge voltage inverter circuit as an active filter. This study was carried out with a real object, and more attention was paid to it. Structural models of electrical energy quality assurance systems, the calculation of control system elements and experimental results are presented. In particular, the use of a half-bridge voltage inverter circuit was considered as a replacement for the passive filter of the battery charger and rectifier device. AC voltage regulators are also used as compensators for higher-current harmonics, namely active filters and reactive power, voltage drop, voltage unbalance and flicker effect compensators. Block diagrams of power quality conditioners are presented, control algorithms are developed and the results of the current high-frequency harmonics compensation, reactive power and signal balancing are presented. The results of an active filter experiment based on the NRT 160.220 charge-rectifier device circuit showed a reduction in ripple of up to 1% with smaller dimensions compared to a passive filter. The control characteristics and external characteristics of the regulators are removed. The dependences of the current THD factor and the power factor are presented depending on the modulation depth for AC voltage regulator circuits used as power quality conditioners.

A Review of Symmetry-Based Open-Circuit Fault Diagnostic Methods for Power Converters

“…This topological symmetry means that the voltage/current output from each phase of the converter are also symmetrical, with only a specific phase angle difference [22]. But when there is a fault in the converter, the topological symmetry will be disrupted, and the symmetry of the output signals of each phase will also change accordingly [23]. So, how do we measure the change in symmetry?…”