Power optimal distribution control method of energy storage of all-vanadium redox flow battery used in high-capacity wind power plant

Abstract

The invention provides a power optimal distribution control method of energy storage of an all-vanadium redox flow battery used in a high-capacity wind power plant. The power optimal distribution control method of the energy storage of the all-vanadium redox flow battery used in the high-capacity wind power plant adopts an all-vanadium redox flow battery (VRB) energy storage systems port with cascade connection between a direct current (DC) / alternating current (AC) convertor and a bi-direction DC / DC convertor. Difference of values of state of charge (SOC) of VRBs in a process of restraining power fluctuation of the wind power plant, wherein the VRBs are connected in parallel in a multi-level mode is considered. A power distribution module with a first choice of a charging state of each level VRB being an optimal charge-discharge battery set and an optimizing power distribution unit of corresponding maximum charge-discharge power a limiting value of charge-discharge voltage being the constraint condition is designed, wherein the power distribution module is capable of achieving a multi-level VRB system. According to the power optimal distribution control method, a conventional distribution principle of average power is abandoned, power fluctuation of the wind power plant is restrained well, number of circulate charge-discharge times of each VRB set in a high-capacity energy storage system is effectively reduced at the same time, and the batteries are enabled to operate in a safe and stable operation area.

Description

technical field [0001] The invention belongs to the technical field of battery energy storage for wind farm operation, and particularly relates to a power optimization distribution control method for multi-stage all-vanadium redox flow battery energy storage used in large-capacity wind farms, specifically including the all-vanadium redox flow battery energy storage system in stable A control method for the given value of the smoothing target power assigned to each VRB group during the power fluctuation process of the wind farm. Background technique [0002] With large-scale wind power connected to the grid, the fluctuation and randomness of its output power have brought an impact on the safe and stable operation of the power grid, and energy storage technology is one of the effective means to solve these problems, such as at the outlet side of wind farm grid connection The installation of energy storage power stations with a certain capacity can smooth the power fluctuations...

AI Technical Summary

Problems solved by technology

[0003] The energy storage of all-vanadium redox flow battery is being gradually applied due to its simple structure, repeated re-discharging process will not cause the battery capacity to drop, etc. Due to the influence of variables and other factors, the operating status of each battery pack is different, resulting in a difference in the state of charge value

If the stabilization target power assigned to each level of battery pack is improper, it will cause multiple unnecessary charge and discharge cycles of the battery and the occurrence of overvoltage phenomena, which may affect the service life of the battery and safe and stable operation, resulting in wind power power stabilization performance and storage capacity. reduced energy utilization

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