چكيده به لاتين
In this thesis, two quasi-impedance source inverters are proposed. These structures offer higher voltage gain compared to the other conventional impedance source inverters. Impedance source inverters have been considered due to their resistance to output short circuit and also having the ability to increase and decrease the voltage level. In this study, modified structures for impedance source inverters are presented. A high voltage gain factor, a low short-circuit interval, and a high modulation index are attainable using the proposed inverter.
The high voltage level needed in some applications and industries necessitates the increase of the voltage gain of the impedance source inverter to the desired voltage level. In addition, the proposed structures have less voltage stress on the impedance network capacitors. Continuity of the input current is another advantage of the proposed structures. In conventional impedance source converters, primary inrush current as well as discontinuous input current lead to a shorter life of converter components. It also hinders them to be used in systems such as distributed energy resources in which continuous current is required. To solve these problems, quasi-impedance source inverters were proposed; therefore a review of the different types of quasi-impedance source inverters is made, and the advantages and disadvantages of each are mentioned, and the two quasi-impedance source structures are discussed in more detail. In the third chapter, the proposed structures are introduced and steady-state analyses are made for different working modes. Theoretical calculations related to the performance of the proposed structures are described along with the detailed design of the passive elements. Also, in order to show the superiority of the proposed structures over other conventional structures, comparisons are made in terms of the voltage increasing factor and voltage stress on the capacitor between the proposed structures and other conventional structures. Finally, in order to prove the validity of the theoretical relations, the proposed structures were simulated in the PSCAD/EMTDC.
