Low-power bidirectional photovoltaic storage current transformer

Abstract

The invention provides a low-power bidirectional photovoltaic storage current transformer. A grid-connected charge and discharge loop is formed by a storage battery and a two-path interleaved BUCK / BOOST circuit, a bidirectional DC / AC full-bridge circuit, a grid-connected and offline switching circuit and a power grid. The storage battery is connected with the two-path interleaved BUCK / BOOST circuit, the bidirectional DC / AC full-bridge circuit, the grid-connected and offline switching circuit and a load in turn so as to form a sensitive load power supply circuit. A solar cell panel and a photovoltaic input BOOST circuit are connected with the two-path interleaved BUCK / BOOST circuit and the storage battery in turn so as to form a photovoltaic charging circuit. The solar cell panel and the photovoltaic input BOOST circuit are connected with the bidirectional DC / AC full-bridge circuit, the grid-connected and offline switching circuit and the power grid or the load in turn so as to form a photovoltaic grid-connected and offline power generation circuit. A central control microprocessor controls the two-path interleaved BUCK / BOOST circuit, a bidirectional DC / DC full-bridge circuit, the bidirectional DC / AC full-bridge circuit, the photovoltaic input BOOST circuit and the grid-connected and offline switching circuit so that the current transformer is enabled to work under the mode of grid-connected and offline power generation or storage battery discharging or storage battery charging according to the state of the power grid, the storage battery and the solar cell panel.

Description

technical field [0001] The invention relates to an optical storage converter. Background technique [0002] Low-power bidirectional optical-storage converters mainly refer to converters with power levels of 5kW and 3kW. The low-power bidirectional solar-storage converter adds a bidirectional converter connected to the battery on the basis of the photovoltaic inverter, which can realize the functions of photovoltaic power generation, battery energy storage, discharge, and off-grid power generation, and realizes the energy in the battery. Two-way flow with the grid; improve the grid's ability to accept distributed photovoltaic power generation, can accept dispatching instructions, and provide active and reactive power according to the instructions; the most important thing is that it can cut peaks and fill valleys, stabilize peak and valley power, and improve grid performance quality and economic efficiency. [0003] The low-power bidirectional optical-storage converter has ...

AI Technical Summary

Problems solved by technology

[0004] The inverter part of the existing bidirectional solar-storage converter is a common photovoltaic inverter structure, which is composed of a BOOST boost circuit and a full-bridge inverter circuit. The bidirectional converter part is a single-circuit Cuk circuit or a full-bridge circuit. It is composed of a bidirectional BUCK / BOOST circuit; the CUK circuit is a hard switch mode, and the efficiency is relatively low; the full bridge circuit plus a bidirectional BUCK / BOOST circuit is because the full bridge circuit directly charges the battery during charging, resulting in large charging ripple or Need to increase the filter capacitor to increase the cost

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