Photovoltaic grid-connected inverter and photovoltaic grid-connected inverter control method

Abstract

The embodiment of the invention discloses a photovoltaic grid-connected inverter and a photovoltaic grid-connected inverter control method, and the photovoltaic grid-connected inverter and the photovoltaic grid-connected inverter control method are used for improving the efficiency of a photovoltaic power generation system. The photovoltaic grid-connected inverter comprises a plurality of DC-DC converters, a DC-AC converter, a plurality of independent MPPT controllers and a concentrated MPPT controller. The independent MPPT controllers correspond to the DC-DC converters one by one. The independent MPPT controllers are used for achieving control over the input power of the DC-DC converters. The concentrated MPPT controller corresponds to the DC-AC converter. The concentrated MPPT controller is used for achieving control over the operation state of the DC-DC converters and the output power of the DC-AC converter. The output ends of the DC-DC converters are connected with the input end of the DC-AC converter after being connected in parallel. According to the photovoltaic grid-connected inverter and the photovoltaic grid-connected inverter control method, the concentrated MPPT controller can achieve control over the operation state of the DC-DC converters and the output power of the photovoltaic grid-connected inverter, and the efficiency of the photovoltaic power generation system is improved.

Description

technical field [0001] The invention relates to the field of industrial control, in particular to a photovoltaic grid-connected inverter and a control method for the photovoltaic grid-connected inverter. Background technique [0002] The photovoltaic grid-connected power generation system is mainly composed of photovoltaic arrays and grid-connected inverters. The direct current generated by photovoltaic modules is converted into alternating current that meets the requirements of the mains grid through the grid-connected inverter and then directly connected to the public grid. The grid-connected inverter It has the function of maximum power point tracking (MPPT) of photovoltaic modules and grid current control, such as figure 1 As shown, generally speaking, the photovoltaic grid-connected inverter can realize the above two functions through DC-AC conversion. Composition, and the objectively existing component mismatch reduces the power generation of the photovoltaic power ge...

AI Technical Summary

Problems solved by technology

[0004] However, this kind of photovoltaic grid-connected inverter needs to undergo PWM chopping due to the operation of the DC-DC converter, and the corresponding components will generate losses. There may be a greater power loss of components due to PWM chopping than due to photovoltaic components In the case of l...

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