Photovoltaic energy storage inverter off-grid MPPT perturbation method

Abstract

The invention relates to a photovoltaic energy storage inverter off-grid MPPT perturbation method. The method comprises the steps that: an independent power loop connected with a photovoltaic panel to form a photovoltaic loop is set, and an independent charge and discharge loop connected with a battery to form a charge loop and a discharge loop is set; the voltage of a bus is detected; when the voltage of the bus is larger than the upper limit of a control reference voltage of an off-grid system, a photovoltaic energy storage inverter stops the MPPT control over the photovoltaic panel, the voltage of the bus is stabilized to the control reference voltage of the off-grid system, and the discharge loop of the battery is switched off; when the voltage of the bus is lower than the lower limit of the control reference voltage of the off-grid system, the photovoltaic energy storage inverter starts the MPPT control over the photovoltaic panel, the PV voltage of the photovoltaic panel is controlled to a photovoltaic maximum power point, and the battery is controlled by the discharge loop to carry out discharging; or else, the off-grid system maintains the current work state. By applying the method, the photovoltaic off-grid application power configuration restriction and the photovoltaic utilization rate are greatly improved, and the photovoltaic application stability in a district without a power grid is realized.

Description

technical field [0001] The invention relates to the field of photovoltaic energy storage, in particular to an MPPT disturbance method applied in an off-grid system. Background technique [0002] At present, the application of photovoltaic energy storage in off-grid systems mainly uses photovoltaic panels as an independent charging source, which has MPPT function during charging. The failure of MPPT makes the system configuration power limited, the photovoltaic utilization rate is not high, and the charging power provided by photovoltaics during the battery discharge process affects the battery life. Contents of the invention [0003] The purpose of the present invention is to provide a photovoltaic energy storage inverter off-grid MPPT disturbance method that improves the power configuration limit and photovoltaic utilization of photovoltaic off-grid applications [0004] In order to achieve the above object, the technical scheme adopted in the present invention is: [0...

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Problems solved by technology

[0002] At present, the application of photovoltaic energy storage in off-grid systems mainly uses photovoltaic panels as an independent charging source, which has MPPT function during charging. The failure of MPPT makes the system configuration power limited, the utilization rate of photovoltaics is not high, and the charging power provided by photovoltaics during the battery discharge process affects the service life of the battery

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