Photovoltaic grid-connected inverter

Abstract

The invention discloses a photovoltaic grid-connected inverter which is composed of MPPT, a controller, a PV array, a filter, a power grid, a voltage and current detection module and a topological circuit structure. The PV array is connected with the topological circuit structure through a capacitor. The signal output end of the PV array is connected with the signal input end of the controller through the MPPT. The output end of the controller is connected with the topological circuit structure. The topological circuit structure is connected with the filter. The filter is connected with the input end of the voltage and current detection circuit through the power grid. The output end of voltage and current detection is connected with the signal input end of the controller. Compared with the inverters in the prior art, a novel phase lock technology and a nonlinear control strategy are adopted to improve the performance of the photovoltaic grid-connected inverter on the basis of deeply researching the mathematical model of the photovoltaic grid-connected inverter and the control strategy of the photovoltaic grid-connected inverter under the asymmetric power grid so as to improve the capacity of low voltage ride through on the basis of reasonable reactive compensation.

Description

technical field [0001] The invention relates to an inverter, in particular to a photovoltaic grid-connected inverter. Background technique [0002] The low-voltage ride-through technology of the photovoltaic grid-connected power generation system means that when the voltage of the photovoltaic grid-connected point drops, the photovoltaic array can remain connected to the grid, and even provide a certain amount of reactive power to the grid to support the recovery of the grid until the grid returns to normal, thus "ride through" "This low voltage time (area). The "Technical Regulations for Connecting Photovoltaic Power Plants to the Grid (Trial)" drafted by the State Grid Corporation of China clearly stipulates the requirements for the LVRT capability of large and medium-sized photovoltaic power plants when the power grid fails and formulates relevant standards. [0003] At present, due to the relatively small capacity of photovoltaic power plants put into operation in China...

AI Technical Summary

Problems solved by technology

In the early morning of February 24, 2011, a single feeder failure of a wind farm in Jiuquan, Gansu affected 11 wind farms in the area and caused a large-scale off-grid accident of wind turbines. The adjustment ability of the device is poor, and the operation and management of the wind farm is defective

Images