Power ramp rate control for grid connected photovoltaic system

Grid-connected photovoltaic (PV) generation attracts increasing attention in countries around the world and it has been extensively studied during last ten years. In the literature, the control system for PV systems has been designed to respond extremely fast to changed weather condition, and the whole regulating duration is generally within tens of milliseconds. As PV installation is moving towards large scale and high penetration today, fast maximum power point tracking (MPPT) control, or in other words fast PV power control, is not always a better option for power systems, because it may cause power surge with rapid sunlight intensity increase, which can further result in network overvoltage, and this could lead to line circuit breaker tripping and damage to customers´ appliances. In this paper, a new control method is proposed to control PV power ascending rate, so the whole process can become much smoother, and some valuable time can be left for tap changer to step down line voltage.