Single phase five levels inverter using Leblanc transformer for power quality improvement

Abstract

Non-linear loads that rely on electrical power generate harmonic currents that disturb the power supply and cause disruptions with other users, which results in signal alteration and high harmonic power. The resulting harmonic currents are able to provoke a heating of the material and a breakdown of the protection systems. Thus, as a solution, active power filters are used to reduce disturbances. Nevertheless, different methods of extracting harmonic currents that are used to control the active power filters, most of the time assume that the filter elements have little effect on the performance of the control system if it is well designed, algorithms. In the past, Leblanc and Scott connected transformers used to be a means to interconnect three-phase and two-phase systems. Today, three-phase systems have become so universal that it is seldom to require such connections. They can also be utilized to diminish the scale of phase unbalance in the cases where single-phase loads are fed from three-phase supplies. In other words, it is possible that they might still be encountered, on occasions, for such applications. The main objective of this project is to supply single-phase loads such as electrified railway systems, electric vehicle chargers or to supply residential groups using solar or wind energy connected from a three-phase network. A configuration that is used as an interface from a single phase to the three-phase power grid and loads including five-level dc/ac converter uses Leblanc transformer/Scott transformer. Both converters enable compensating harmonics, reactive power and load imbalances, the link between two single-phase sources and a three-phase source. A control is also developed to achieve these objectives, a technique of balancing of the currents allowed to balance the two currents in the secondary of the Leblanc transformer is proposed, which has an impact on the balance of current on the side of the three-phase network at the primary of the Leblanc transformer.

Date	28 Jun 2018
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Kamal Al-Haddad (Supervisor) & Abdelhamid Hamadi (Co-supervisor)