Cascaded dual buck inverter with sensorless current control method for grid connected photo voltaic systems

This paper presents a grid connected cascade dual buck inverter with Sensorless current control method to utilize the present renewable energy structure. A grid-tie control system is proposed for cascaded dual-buck inverter with both active and reactive power flow capability in a wide range for renewable energy and distributed generation sources. A cascaded two switch dual buck inverter with two power MOSFETs and two fast recovery diodes is used as grid connected inverter. It eliminates the dead time issues and has no shoot through concerns. The freewheeling current flows through independent fast recovery diodes, which reduces the reverse recovery loss of the diodes. A digital current mode controller mechanism implemented by utilizing a sensorless current control method. The current mode loop is Sensorless, relying on constants and internal loop states, removing the need to sense controlled voltages or current for inner loop.