Impedance source type battery energy storage power electronic conversion device

Abstract

The invention provides an impedance source type battery energy storage power electronic conversion device. The device comprises a battery energy storage unit, a bidirectional DC / AC converter, a filtering inductor, an impedance source network, a full-control type device and a control system; the positive pole of the battery energy storage unit is connected with the positive end of the bidirectional DC / AC converter; the negative end of the bidirectional DC / AC converter is connected with the input end of the impedance source network; the output end of the impedance source network is connected with the negative pole of the battery energy storage unit, and the other two ports of the impedance source network are connected with the full-control type device; and the bidirectional DC / AC converter outputs three-phase alternating current and is connected with a power grid through the filtering inductor. With the device of the invention adopted, voltage boosting and voltage reduction transformation is realized, and direct current-side input voltage can change in a wide range; and the upper full-control type power device and lower full-control type power device of the same bridge arm in the bidirectional DC / AC converter can be switched on simultaneously, and therefore, the reliability of the work of converter is high. Dead zones are not required to be added in modulation, so that output harmonic content is low. Compared with a traditional impedance source inverter, the device can achieve bidirectional energy flow and is smaller in capacitance and voltage stress under the same voltage boosting capacity.

Description

technical field [0001] The invention relates to a power electronic converter device, in particular to an impedance source type battery energy storage power electronic converter device. Background technique [0002] Renewable energy power generation represented by photovoltaic and wind power and its related technologies are developing rapidly, but affected by meteorological factors, its output presents the characteristics of intermittent, fluctuating and uncontrollable, which limits its grid-connected capacity. The energy storage technology represented by battery energy storage has become the most effective way to solve the problem of grid integration of renewable energy power generation. [0003] A battery energy storage system usually includes a battery energy storage unit and a grid-connected interface circuit composed of power electronic devices. Generally, the DC voltage output by the battery energy storage unit is low, and with the change of the battery output, the DC ...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the above-mentioned defects, the present invention provides an impedance source type battery energy storage power electronic conversion device, which retains the advantages of the traditional impedance source inverter allowing the bridge arm to pass through, the output waveform distortion is small, and the advantages of buck-boost conversion capability, and at the same time It overcomes the shortcomings of traditional impedance source inverters, such as large start-up surge current, high capacitor voltage stress and inability to flow bidirectionally.

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