A new 15-level inverter configuration with fault tolerant capability for PV applications

摘要

Power generation using PV systems is becoming more popular due to lack of availability of fossil fuels. As power generated with PV system is DC, inverters are required to convert it into AC quantity. Conventional two-level inverters are popularly used in this application. But, the output voltage of these inverters contains more harmonic component which will deteriorates lifetime of the load. Moreover, if any one switch of two-level inverter fails, entire system has to be shutdown. To overcome these disadvantages, a novel 15-level inverter is proposed in this paper. The proposed inverter configuration is developed by using three isolated DC sources, six two-quadrant switches and four four-quadrant switches. Hence, this inverter requires only ten switching devices which is very less number compared to number of switches required in conventional 15-level inerter. As availability of isolated dc sources are common in case of different PV system modules, three dc sources can be easily obtained. The proposed inverter is simulated in MATLAB/Simulink and results are presented. The analysis is carried to study the behavior of the inverter during the failure of some switching devices and Dc sources. This configuration can be extended to get more number of voltage levels by cascading proposed inverter units.