Power control method and device for hybrid energy storage system of direct drive wind turbine

Abstract

The invention discloses a power control method and device for a hybrid energy storage system of a direct drive wind turbine. The method includes: outputting power P of the wind turbine WT The total power P of the hybrid energy storage system is obtained by filtering out low frequency components HESS ; The total power P HESS After the low-pass filter, the first target power P of at least two lithium battery energy storage devices is obtained * batt , the total power P HESS with the first target power P * batt The difference is used as the second target power P of at least one super capacitor energy storage device * SC ;according to the second target power P * SC and the actual current i of the supercapacitor energy storage device SC Control the power of at least one super capacitor energy storage device; according to the first target power P * batt And the SOC values ​​of the at least two lithium battery energy storage devices control the charging and discharging modes and power of the at least two lithium battery energy storage devices. The implementation of the present invention can avoid large power fluctuations caused by MW-level permanent magnet synchronous wind turbines with changes in wind speed, and at the same time avoid frequent charging and discharging switching of lithium batteries.

Description

technical field [0001] The invention relates to the field of wind power generators, in particular to a power control method and device for a hybrid energy storage system of a direct-drive wind turbine. Background technique [0002] Renewable energy such as wind power has the characteristics of volatility, intermittency and uncertainty, and it is difficult to maintain stable wind power output. With the large-scale integration of wind power into the grid, it has had an important impact on the safe and stable operation of the power system, and at the same time limited the development of wind power itself. High-efficiency energy storage technology can realize the translation of electric energy in time and space, improve the ability of the grid to absorb wind power and the dispatchability of the grid to wind power. [0003] The application of smoothing wind power output with a single energy storage medium is mature, mainly using batteries, supercapacitors and fuel cells. Due to...

AI Technical Summary

Problems solved by technology

With the large-scale grid connection of wind power, it has had an important impact on the safe and stable operation of the power system, and at the same time limited the development of wind power itself.

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