Multi-converter-chain alternating-current and alternating-current frequency converter based on energy storage

Abstract

The invention discloses a multi-converter-chain alternating-current and alternating-current frequency converter based on energy storage. The system comprises a new energy power generation base and anAC / AC frequency conversion device, the input end of the AC / AC frequency conversion device is connected with the new energy power generation base, the output end of the AC / AC frequency conversion device is connected with an AC power grid and comprises a switch module and a plurality of cascaded frequency conversion modules, each frequency conversion module comprises an energy storage circuit and afrequency conversion circuit, and the energy storage circuits are connected with the frequency conversion circuits in parallel; the AC / AC frequency conversion device is used for converting the first frequency three-phase voltage of the new energy power generation base into a second frequency three-phase voltage, and the first frequency is smaller than the second frequency; and the power transmission line is connected with the new energy power generation base and the AC / AC frequency conversion device. The transmission capacity of the line is multiplied by adopting the power transmission frequency lower than the second frequency; according to the multi-converter-chain alternating-current frequency converter, the transmission distance is increased, the energy storage circuit is arranged in each frequency conversion module, once an alternating-current power grid on the power frequency side breaks down, electric energy can be provided for the alternating-current / alternating-current frequency conversion device in time, the alternating-current / alternating-current frequency conversion device can continue to work normally, and then the working efficiency of the multi-converter-chain alternating-current frequency converter is improved.

Description

technical field [0001] The invention relates to the field of power systems, in particular to an energy storage-based AC / AC converter with multiple commutation chains. Background technique [0002] Energy is an important material basis for economic and social development. Accelerating the establishment of a safe, reliable, cost-effective, clean and environmentally friendly modern energy supply system has become a common strategic goal of all countries in the world. In order to effectively solve the problems of energy depletion and environmental pollution, the development of new energy has become the only way to meet the three major challenges of energy security, environmental pollution, and climate change, and to realize the sustainable development of human society. Wind power generation is one of the most mature and large-scale development conditions among new energy power generation technologies. In some areas, the distribution of wind power resources and load centers are ...

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Problems solved by technology

[0004] Therefore, the technical problem to be solved by the embodiments of the present invention is that the frequency conversion device installed in the power transmission system in the prior art obtains electric energy through the AC grid on the power frequency side, but if the transmission line of the AC grid on the power frequency side fails, this It will cause the frequency conversion device to make its inverter topology unable to continue to work normally due to the lack of power

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