Modeling and analysis performance simulation performance of multilevel inverter using bipolar and unipolar switching schemes

Ng , See Man (2014) Modeling and analysis performance simulation performance of multilevel inverter using bipolar and unipolar switching schemes. Project Report. UTeM. (Submitted)

Text MODELING AND ANALYSIS PERFORMANCE SIMULATION PERFORMANCE OF MULTILEVEL INVERTER USING BIPOLAR AND UNIPOLAR SWITCHING SCHEMES 24pages.pdf Download (346kB)

Abstract

Multilevel inverter is one of the popular converter topologies used in high power medium- voltage (MV) drives due to able operate at high direct current (DC) voltage which is achieved using series connection of power semiconductor switches. Multilevel inverter can generate output voltage with very low harmonic distortion and synthesis a staircase voltage output waveform by having multiple voltage level. Various topologies of multilevel inverters are introduced; however, in this project, the cascaded seven-level multilevel inverter will be discussed due to easy control method implementation. Unipolar and bipolar switching schemes are used to analyze the performance of seven-level cascaded H-bridge inverter. Both of these SPWM voltage modulation type are selected because these method able to double the switching frequency of the inverter voltage effectively. The major problem in designing multilevel inverter is to design filtering in order to filter the low harmonic which is very hard to eliminate. Bipolar switching PWM inverter is able to filter the low frequency harmonics compared to the unipolar switching schemes inverter. From the simulation results, it can be clearly seen that by using bipolar switching scheme, the total current harmonic distortion (THDi) and voltage harmonic distortion (THDV) for R, RL and RC loads are low compared to unipolar switching scheme. Therefore, the bipolar switching scheme is more suitable because the common domestic loads used are RL load. MATLAB Simulink is used to model the seven levels cascaded multilevel PWM inverter

Actions (login required)

View Item