The converters connected to the power grid, including rectifier and inverter. The rectifier uses DC voltage outer loop control method and the input current inner loop control method, three-phase inverter output current uses SPWM modulation. With the capacity of the system increasing, the capacity of a single converter can no longer meet the requirements, for improving the system's power grid, reliability and efficiency, converters can be paralleled. Parallel operation generates loop current; one of the effective methods of suppressing the loop current is to connect limiting inductance in the inverter AC side. Through simulation, gets the suitable inductance value, and researches the dead zone time affecting on the loop current. When the dead zone times of two modules are not equal, the loop current increases.
Single-stage Three-phase Differential-mode Buck-Boost Inverters with Continuous Input Current for PV Applications