A new binary hybrid cascaded H-bridge multi level converter for power quality applications

摘要

Power quality is the main concern of this era and most of the power quality conditioners using the power converters as the main part. Hence performance of the converter is very important but low level converters create harmonic distortions in the output voltage and high dv/dt stresses leading to electromagnetic compatibility (EMC) issues and higher harmonic distortion results in malfunction of the device or other extra heating losses. A new approach to voltage source multilevel converter has been proposed here which creates a smoother sinusoidal output waveform reducing the THD (Total Harmonic Distortion) and hence finds a better position in the list of multilevel converters used for power quality conditioners. As the number of levels increases the number of power semiconducting devices also increased. In this paper, a new inverter is proposed with lower number of switches and sources in order to acquire maximum level. A 15 level inverter which employs three isolated sources and 7 switches has been developed. The new topology is framed out by cascading three half bridge and a single 'H-bridge configuration. The voltage level of each source is selected such that it has a binary weighted voltage level. In addition with the reduction of switches, a binary combination of the dc sources is selected for each level to reduce the THD as well as to reduce the number of DC sources. The performance of proposed converter is evaluated using MATLAB with its Simulink and Simpowersystems.