Inverting control system and method based on grid drop testing in photovoltaic power generation system

A photovoltaic power generation system and inverter control technology, applied in photovoltaic power generation, single-network parallel feed arrangement, reactive power compensation, etc., can solve problems such as bus voltage rise and achieve the effect of reducing voltage changes

CN103997066AInactive Publication Date: 2014-08-20SUZHOU UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2014-08-20
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses an inverting control system and method based on grid drop testing in a photovoltaic power generation system. The method comprises the steps that a photovoltaic array converts solar energy into electric energy, a DC-DC converter carries out MPPT of the photovoltaic power generation system, and an inverter inverts direct current into high-quality alternating current to be sent to a grid; whether the grid drops or not is detected, and if the grid does not drop, an MPPT controller in a pre-controller works, and more energy is obtained from the photovoltaic array; if the grid drops, the MPPT controller in the pre-controller stops working, a first PI controller works, voltage of direct current bus keeps stable in the low-voltage ride through process, a grid-connected current feed unit provides reactive current, and the grid-connected current amplitude is kept constant. The inverting control system and method based on grid drop testing in the photovoltaic power generation system can reduce severe sudden changes of the voltage of the direct current bus in the low-voltage ride through process and prevent the grid-connected current from exceeding a flow value.
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Description

technical field

[0001] The invention relates to the technical field of photovoltaic power generation systems, in particular to an inverter control system and method based on grid drop detection in photovoltaic power generation systems. Background technique

[0002] In the past few years, photovoltaic grid-connected power generation systems have made great progress in both the number and scale of installations, and the proportion of photovoltaic power generation in the power grid has increased year by year. Driven by the vigorous development of photovoltaic grid-connected systems, many countries have revised new grid codes. In the "Technical Regulations for Connecting Photovoltaic Power Stations to the Grid" issued and implemented by the State Grid Corporation of China on May 6, 2011, it was the first time to clearly put forward the requirements for low voltage ride through (LVRT) for large and medium-sized photovoltaic power stations. It can be seen that photovoltaic system...

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Embodiment Construction

[0040]In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0041] ginseng image 3 As shown, in a specific embodiment of the present invention, the photovoltaic power generation system is a two-stage photovoltaic grid-connected system, which specifically includes the following parts:

[0042] Photovoltaic array 10 for converting solar energy into electrical energy;

[0043] DC-DC converter 20,...