Energy storage access system

Abstract

The invention discloses an energy storage access system used for realizing the energy conversion of a plurality of energy storage batteries and an electric network. The energy storage access system comprises a bidirectional PWM (Pulse-Width Modulation) rectifier, an AC (Alternating Current) LCL (Lower Control Limit) filter circuit connected between the AC side of the bidirectional PWM rectifier and the electric network, a DC (Direct Current) bus, a plurality of bidirectional DC / DC converters connected with the DC side of the bidirectional PWM rectifier through the DC bus and one-to-one correspondent to the energy storage batteries, a plurality of DC LC (Launch Control) filter circuits respectively connected between the bidirectional DC / DC converters and the corresponding energy storage batteries, and a control system used for respectively controlling the bidirectional PWM rectifier and the bidirectional DC / DC converters by outputting a driving signal. The energy storage access system disclosed by the invention drives the energy storage batteries to independently work and dispatches corresponding energy storage batteries according to different control targets to play the characteristics of the current energy storage batteries to the utmost extent so as to realize large scale direct parallel operation of the energy storage batteries.

Description

technical field [0001] The invention relates to the technical field of power system energy storage, and relates to an energy storage access system. Background technique [0002] In order to make the power system run stably, it is necessary to control its power generation, power transmission, power distribution and power consumption to be completed at the same time, and to keep it in a state of dynamic balance at all times. If there is an instantaneous power imbalance, it will cause system security and stability problems. Due to their inherent randomness and intermittent characteristics, green new energy sources such as photovoltaic power generation and wind power generation make it impossible to formulate and implement accurate power generation plans like other traditional power sources, which puts enormous pressure on the operation and scheduling of the power grid; At the same time, the large-scale access of renewable energy has brought problems such as reactive power, pow...

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Problems solved by technology

[0004] Common energy storage batteries include lithium batteries, flow batteries, sodium-sulfur batteries, lead-acid batteries and other energy-type batteries. The obvious characteristics of this type of battery are that the charging and discharging current should be as stable as possible, and it is not suitable to start frequently. The dynamic response is slow, which is limited to manufacturing. The horizontal cycle life is low; supercapacitor (supercapacitor battery) is a power type energy storage component that has developed rapidly in recent years. It has the advantages of high power density, fast charge and discharge speed, wide operating temperature, and long service life. Disadvantages such as low energy density

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