Control method and device of inverter and inverter system

Abstract

The embodiment of the invention provides a control method and device of an inverter and an inverter system. The control method and device of the inverter and the inverter system solve the problems that in a photovoltaic grid-connected electricity generation system, in order to improve the utilization rate of direct current at the two ends of a solar panel for the inverter, common mode components are usually injected into modulating waves of the inverter for three times, and therefore the conversion efficiency of the inverter is low. The control method of the inverter comprises the steps that the voltage of the direct current currently output by a solar panel array connected with the inverter is determined, when the voltage of the direct current is larger than or equal to the current preset voltage, the modulating waves are output to the inverter, the modulating waves only contain periodic waves with a preset frequency, and the modulating waves are used for controlling the inverter to convert the direct current output by the solar panel array into alternating current, and when the inverter converts the direct current with the voltage larger than or equal to the current preset direct current into the alternating current under the control of the modulating waves, the distortion of the alternating current is located in a range currently permitted by a power grid where the inverter is connected into.

Description

technical field [0001] The invention relates to the technical field of new energy power generation, in particular to an inverter control method, device and inverter system. Background technique [0002] In photovoltaic power generation technology, solar panel arrays and inverters are two important components in photovoltaic grid-connected power generation systems. The solar panel converts solar energy into electrical energy and outputs direct current, while the inverter converts the direct current of the solar panel into usable alternating current and incorporates it into the grid. [0003] Although solar energy resources are infinite, the conversion efficiency of solar cells is very low due to the low solar radiation density. At present, the conversion efficiency of most solar cells is only 10%-20%. In this context, improving the conversion efficiency of the inverter is crucial to improving the overall efficiency of the photovoltaic grid-connected power generation system. ...

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Problems solved by technology

[0007] Embodiments of the present invention provide an inverter control method, device, and inverter system to solve the problem of improving the utilization of the DC voltage at both ends of the solar panel by the inverter in the existing photovoltaic grid-connected power generation system. rate, usually three common-mode components are injected into the modulation wave of the inverter, which leads to the problem that the conversion efficiency of the inverter is reduced

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