Dynamic power distribution control method of urban rail hybrid energy storage system

Abstract

The invention aims to solve a problem of traction network voltage safety caused by instantaneous high power, short-time high energy and the like of urban rail transit traction braking energy. In combination with a characteristic that a super capacitor and a battery have very strong complementarity in performance, a hybrid energy storage system of a double-DC / DC converter framework formed by supercapacitor-battery parallel connection is used for recycling traction braking energy. A double-closed-loop control strategy based on train traction power feedforward is provided on the basis of traditional double-closed-loop PI control, a fuzzy inference system and a low-pass filtering method are combined to cooperatively control power distribution of an energy storage element, and optimal energy management of the hybrid energy storage system is achieved by controlling a power distribution proportion. In the invention, a voltage fluctuation of a traction network can be effectively inhibited, anenergy utilization rate is improved, power of the energy storage system is optimized by monitoring a state of charge SOC of the energy storage device in real time, phenomena of overcharge and overdischarge of the energy storage element are prevented, and overall performance and cost performance of the hybrid energy storage system are improved.

Description

technical field [0001] The invention relates to the technical field of urban rail transit energy storage and energy saving, in particular to a power dynamic distribution control method for an urban rail hybrid energy storage system. Background technique [0002] Urban rail transit has been vigorously promoted in many cities due to its advantages such as large carrying capacity, punctuality and speed, and less environmental pollution. Urban rail transit lines consume a lot of energy and have high operating voltage requirements. Using energy storage in the DC traction network to recover excess braking energy is an effective means to achieve energy conservation in urban rail transit and ensure the voltage safety of the traction network. When the train brakes, the traction motor acts as a generator to deliver energy to the traction network, and the energy storage system absorbs the braking energy; when the train starts to accelerate, the energy storage system releases energy to ...

AI Technical Summary

Problems solved by technology

However, during the braking process of urban rail trains, up to 3MW / 15kW·h of energy can be fed back. It is difficult for a single-device energy storage system to meet the dual demands of high power and high energy. In order to suppress the sharp rise of traction network voltage, hybrid energy storage is often used form to meet the dual needs of high power and high energy

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