Dynamic adjustment control method of discharge threshold for urban rail transit battery storage system based on energy transfer

Abstract

The invention relates to relates to the technology of urban rail transit energy storage and specifically to a dynamic adjustment control method of discharge threshold for an urban rail transit batterystorage system based on energy transfer. The method of the invention comprises following steps: a control system of a battery energy storage system is communicated with a battery a manage system to obtain the voltage, current and SOC parameters of the battery in real time; the busbar voltage Udc can be obtained through a voltage sensor; according to a set SOC reference value SOCref, the actual SOC value of the energy storage system is compared with the SOCref to obtain the difference [delta]SOC between the two; a corrected quantity [delta]U of a discharge threshold is obtained through a section proportional regulator; an actual discharge threshold value Udis is obtained according to an initial discharge threshold value Udis0 and the corrected quantity [delta]U of a discharge threshold. According to the invention, SOC of the energy storage system can be made fluctuate within one scope to prevent the SOC of the energy storage system from being too high or too low; the discharge quantityof the energy storage system is enlarged and the substation output power peak value is reduced.

Description

technical field [0001] The invention relates to an urban rail transit energy storage technology, in particular to a method for dynamically adjusting the discharge threshold of an urban rail transit battery energy storage system based on energy transfer. Background technique [0002] Urban rail transit is an important part of the public transportation system and an important means to solve urban traffic congestion. The operation characteristics of urban rail transit are short distance between stations and frequent starting and braking during operation. When the train brakes, the motor works in the power generation state, and the generated electric energy is returned to the grid, which is called regenerative braking; if the regenerative braking energy cannot be effectively absorbed by the adjacent traction train, it will lead to energy accumulation in the traction network and an increase in network voltage, which will lead to Regeneration fails. At the same time, with the inc...

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Problems solved by technology

[0016] The technical problem to be solved by the present invention is a dynamic adjustment control method for the discharge threshold of the urban rail transit battery energy storage system based on energy transfer, so that it can: 1. Solve the problem of unbalanced charge and discharge of the battery energy storage system without affecting the energy saving effect Under the premise of , realize the control of the SOC of the energy storage system, make the SOC of the energy storage system fluctuate within a certain range, and prevent the SOC of the energy storage system from being too high or too low; 2. Propose a dynamic SOC adjustment strategy based on energy transfer, according to Departure interval adjustment SOC ref , under the premise of not affecting the recovery of regenerative braking energy, the energy storage system is used to transfer the regenerative braking energy recovered during the low peak period / flat peak period to the peak period, so as to increase the discharge capacity of the energy storage system during the peak period and reduce the Substation output power peak value

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