New pulse width modulation technique to reduce losses for three-phase photovoltaic inverters

Nowadays, most three-phase, “of the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. Tis article proposes a novel control strategy called a 120∘ bus clamped PWM (120BCM). Te 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for flm capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Tus, the total cost of ownership of the PV system will decrease signifcantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are signifcantly reduced. Te full system setup is designed and presented in this paper with some practical result