A strategy for solar photovoltaic power converter control to improve power system transient stability

Abstract

In the modern power grid, the solar PV system is connected to the grid via power electronics converters. Power electronics interfaces must be properly controlled to stable the operation of the solar PV system during normal and fault conditions. When there is a grid fault, the DC link voltage goes extremely high, as the incoming maximum PV panel DC power cannot injected to the grid. This is due to severe voltage dip that leads the power unbalance and instability. This paper modelled and simulated the grid connected solar PV system to analyse the transient stability limit with maximum power point tracking (MPPT) algorithm and without MPPT control boost converter. A novel control strategy is proposed for cut-off MPPT controller during fault condition to control the dc link voltage rise. The performance of the proposed mechanism is evaluated on the solar PV connected single machine infinite bus (SMIB) system with larger disturbances. The results show significant improvement in transient stability of the system. Simulation results of MPPT and without MPPT controllers are presented for comparison purpose. Transient stability is evaluated by critical clearing time (CCT) and DC-link voltage deviation of solar PV system.