A New Multilevel Active Power Filter Using Switches Meticulously Controlled

Abstract

Shunt active power filter based on multilevel inverter is used to compensate the power factor and to delete the harmonics. This one permits to reduce the inverse voltages applied to the filter switches and their switching frequencies. Nevertheless, the high number of used switches requires a complicated controller and increases the switching losses; where the necessity of finding another resolution system. In this work a new topology of multilevel inverter is proposed as a shunt active power filter using two IGBT transistors in series of opposite sense meticulously controlled by a parallel control algorithm, with the concept of reduced number of six switches which are able to create five levels of the output voltage. This system substute the classical system of eight switches. The harmonic currents identification is carried out using the instantaneous active and reactive power method. The simulation is performed using Matlab/Simulink. The obtained results show that the filtering performances are well enhanced.

A New Structure of the Nine Level Inverter Used as Active Power Filter with a Reduced Number of Swiches

“…It is placed in parallel to the nonlinear load and the three-phase supply source. It is placated as close as possible to the nonlinear load in order to prevent harmonics propagation in the distribution network and getting high power quality [22]. The block diagram of the nine level ten-switch inverter topology is illustrated in Figure 2.…”

“…The active filter control used in this study is divided into two parts. The first deals with the harmonic isolator based on the instantaneous power theory (pq theory), [21]- [22] in order to extract harmonic currents. The second part is devoted to the logic signals generation to control the filter switches using the Pulse Width Modulation (PWM) technique.…”

Cascaded Symmetric Multilevel Inverter with Reduced Number of Controlled Switches

“…The modulated signal used is of 50Hz. The pulse width modulated switching signal is generated by comparison of these two signals [20]. The resultant modulated multilevel inverter output is given in Figure 7.…”

“…In order to get pure sine wave from the modulated signal of Figure 7, the output modulated wave form is subjected to the LCL filter. The LCL values are computed using [20]. The computed values for the LCL filter Figure 9 using the equations given in [20] are Li= 4mH, Lg= 2.4mH, fres=2.3kHz, and Rsd=7.5 Ω.…”

“…The LCL values are computed using [20]. The computed values for the LCL filter Figure 9 using the equations given in [20] are Li= 4mH, Lg= 2.4mH, fres=2.3kHz, and Rsd=7.5 Ω. The simulated filtered output is shown in Figure 10.…”