Low-voltage ride-through method for photovoltaic inverter

Abstract

The invention discloses a low-voltage ride-through method for a photovoltaic inverter. The method comprises the following steps of: acquiring a power grid bus side voltage by using a voltage sensor, causing the power grid bus side voltage to pass through a conditioning circuit and transmitting the power grid bus side voltage into a digital signal processor; capturing and calculating a standard voltage amplitude value by using the digital signal processor; judging whether the standard voltage amplitude value is less than a set lower low-voltage limit or not; if the standard voltage amplitude is less than the set lower low-voltage limit, disconnecting the inverter from a contactor of a power grid; on the contrary, judging the duration of the standard voltage amplitude at the lower limit, keeping the inverter connected with the power grid if the duration is less than a standard, and on the contrary, disconnecting the inverter from the power grid; judging whether a power grid voltage unit value is less than a set upper voltage limit or not; performing grid-connection normally on the inverter if the power grid voltage unit value is greater than the set upper voltage limit; on the contrary, judging the duration of the power grid voltage unit value at the upper limit, keeping the inverter connected with the power grid if the duration is less than the standard, and on the contrary, disconnecting the inverter from the power grid; adopting the internally set voltage reference amplitude of the digital signal processor; and realizing inversion by taking the voltage reference amplitude as an inverter reference voltage.

Description

technical field [0001] The invention relates to a low-voltage ride-through of a photovoltaic inverter. The invention relates to a method for improving the grid-connected stability of a photovoltaic inverter. The invention relates to a method for improving the grid-connected reliability of a photovoltaic inverter. The power grid system voltage was temporarily low and disconnected. Background technique [0002] Energy is an important material basis for the existence and development of human society. With the rapid development of society, the demand for energy and resources is increasing. As we all know, non-renewable energy will be exhausted in the near future, and some new energy will come into being. pregnancy. Photovoltaic power generation is a recognized new energy technology with high technical content and great development prospects. This is because solar energy is inexhaustible and inexhaustible, does not produce any waste, has no noise and other pollution, and will no...

AI Technical Summary

Problems solved by technology

[0032] It can be known from the background technical information that the current low voltage ride-through capability of photovoltaic inverters needs to be improved, such as improving the grid-connected stability of photovoltaic inverters, preventing grid system voltage from being disconnected due to low voltage, etc.

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