Design of Solar PV System using T-Source Inverter with Third Harmonic Injected Maximum Constant Boost PWM Control

High efficient solar Photo-Voltaic (PV) inverters are demanded in recent electrical power scenario to satisfy the energy demand. The transformerless single stage T-Source Inverter (TSI) proposes high efficiency due to the voltage boost capability than the conventional Voltage Source Inverter (VSI) and Current Source Inverter (CSI). However in conventional VSI fed solar PV system, to increase the voltage from inverter additional transformer is used. The additional transformer used increases the total size, cost and power losses in the conversion process; as a result the efficiency of the system is reduced. This paper describes the analysis of solar PV system by employing T-Source Inverter (TSI) with Third Harmonic Injected Maximum Constant Boost (THIMCB) PWM control. This TSI based solar PV system overcomes the conceptual and theoretical limitations of VSI and CSI. The TSI have shoot through time period which is responsible for boost in voltage. The voltage stress of switching devices and harmonics are less when compared with the VSI fed solar system. The output voltage of the solar PV system can be increased by increasing the boost factor directly without using the step-up transformer or dc-dc booster circuit. The mathematical expressions for boost factor, shoot through duty ratio, voltage gain and voltage stress are obtained and validated by Matlab/Simulink simulation results.