Low-Frequency ripple influence in the P&O MPPT dynamics response applied in the single-stage DABSR DC-AC converter for interfacing PV to single-phase grid

Abstract

This paper proposes a novel strategy of control and modulation in an isolated single-stage Dual Active Bridge Series-Resonant (DABSR) DC-AC converter specifically for solar photovoltaic arrays connected to a single-phase grid (PV2SPG). The Perturb and Observe (P&O) maximum power point tracking (MPPT) algorithm is implemented and analyzed considering the influence of the low-frequency ripple on the PV side. Aiming to compensate the PV voltage, which varies with the temperature, a duty ratio (DR) control is introduced. Besides, the power flow is controlled by phase shift modulation. The DC-AC converter is compared with an analogous DABSR DC-DC converter that does not have the low-frequency ripple problem to validate the proposed control and modulation. The result simulations validate the proposed control and modulation.