A proposed control strategy to improve the low voltage ride through capability of PV system with keeping the dclink voltage constant

In modern electric power systems, the dependence on solar power is increasing. The grid connected applications are very important with the deficit in conventional power stations due to fuel shortage. This paper focuses on controller design and implementation in grid connected PV systems for low voltage rid through (LVRT) in distribution power systems, this paper proposes a control method to keep the dc-link voltage of PV system constant during low voltage rid through (LVRT). This is done by changing the operating point on the I/V curve of the PV cell from the MPPT point to another point, the active power output of the PV will decrease from the maximum to the needed value. The proposed control system is evaluated under different fault scenarios to test the validity of the control system. The results show that the proposed control system gives the expected performance. The PSCAD package is used for simulating this study.