Advanced Voltage Balancing Discontinuous PWM Technique for Solar PV Fed Grid-Tied NPC Inverters

Multilevel inverters (MLIs) have significantly improved the overall performance, dependability and efficiency of the renewable energy system. Moreover, these can be easily integrated with the superconducting magnetic energy storage (SMES) systems. Maintaining the power qualities of these MLIs is always marked as a major research concern which can be heavily impacted by the pulse width modulation (PWM) strategies. An improved voltage balancing discontinuous PWM (DPWM) scheme is suggested in this work for the single-phase grid-tied 5-level neutral point clamped (NPC) inverter, which can significantly mitigate the fluctuation of the dc-link capacitor voltages as well as the switching losses of the power IGBTs. The reduction in switching losses will give lower thermal stress to the power devices. The proposed DPWM scheme is compared with other existing DPWM schemes for proving its effectiveness. The simulation of the entire system is performed by using MATLAB Simulink and PLECS simulation platform. A lower scale prototype is also constructed in the laboratory.