A novel control strategy for single-phase grid-connected PV generation system with the capability of low voltage ride through

Abstract EN

Motivated by the booming installations of grid-connected photovoltaic (PV) systems, several countries have revised their grid codes in pace with the sustained growth both in quantity and scale.

PV systems with the capability of low-voltage-ride-through (LVRT) will be a trend in the future.

A novel control strategy for single-phase two-stage grid-connected PV systems is introduced in this paper.

Dc-link voltage is flexibly controlled with different stage of two-stage systems to minimize voltage variation during grid-fault period.

In the aspect of current injected to the grid, constant peak current strategy is adopted to avoid triggering over-current protection.

Active and reactive output currents decoupling controlled with second order generalized integrator (SOGI)-based PLL algorithm while the amount of reactive power delivered for grid recovery depends on sag depth of grid voltage.

Simulation results on the whole system shows that the proposed strategy is effective with satisfying steady-state and dynamic performance.