A power grid black start and frequency regulation device and method based on battery packs and liquid air energy storage

Abstract

The invention discloses a battery pack and liquid-state air energy storage-based power grid black start and frequency modulation apparatus and method. The apparatus comprises a liquid-state air energystorage circulation circuit, a liquid-state air power generation circulation circuit, a battery pack, a first switch, an inverter, a second switch, a third switch, a power plant generator set, a power grid, a control unit and a fourth switch; the liquid-state air energy storage circulation obtains liquid-state air by off-peak electricity or the generated energy of renewable energy sources, and stores in a liquid-state air liquid storage tank; when the power grid suffers from large-area power failure, the control unit gives out a black start instruction: the battery pack discharges to start the liquid-state air power generation circulation; the liquid-state air in the outlet of the liquid-state air liquid storage tank is pressurized by a pressure pump and preheated by an evaporator and then enters each level of heaters and expanders to perform power generation based on expansion; the generated energy from the liquid-state air power generation circulation is preferably used for startingthe power plant generator set to recover the power supply for the power grid and meanwhile to supply to itself, thereby lowering the capacity requirement on the battery pack and lowering investment and maintenance cost; in the whole process, the liquid-state air power generation circulation can be started within 2-5min to help the power plant generator set to start power supply quickly; the powergrid can be recovered to realize power supply as normal within a short time; when the power grid has the frequency modulation requirement, the control unit gives out a frequency modulation instruction; the battery pack and the liquid-state air power generation circulation are started synchronously; and the battery pack is high in reaction speed and used for primary frequency modulation while theliquid-state air power generation circulation is used for secondary frequency modulation.

Description

technical field [0001] The invention relates to a new type of power grid black start and frequency modulation system, which is a power grid black start and frequency modulation device and method based on battery packs and liquid air energy storage, belonging to liquid air energy storage, battery energy storage, power grid black start and frequency modulation technical field. Background technique [0002] The stability and accuracy of grid frequency is an important indicator of power supply quality. The influence and harm of grid frequency changes and deviations on users and prime movers are well known. The frequency modulation process is the process of adjusting the energy balance in the power production process. When the frequency of the grid deviates, the frequency of the grid is restored by mobilizing various energy storage and thermal systems for primary frequency modulation (within 30 seconds) and secondary frequency modulation (30 seconds to 30 minutes). [0003] Po...

AI Technical Summary

Problems solved by technology

In the case of a large-scale power outage in the power grid, it is required to quickly restore the power supply. If the power supply cannot be restored in a short time, the national economy will suffer huge losses.

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