Method for determining filter cutoff frequency and output power control method for hybrid energy storage microgrid system

Abstract

The invention discloses a hybrid energy storage micro-grid system cut-off frequency determining method and relates to the technical field of micro-grids. The hybrid energy storage micro-grid system cut-off frequency determining method overcomes the defects that a method of exhaustion is used in an existing hybrid energy storage micro-grid system to determine the cut-off frequency, and consequently the amplitude of output power fluctuates, and the adaptability is poor; the empirical mode decomposition method is used for decomposing the output power of a micro power source into components of different instantaneous frequency grades, and therefore the optimal cut-off frequency for conducting high and low frequency division on the output power at the power source side is obtained. The invention further discloses a hybrid energy storage micro-grid system output power control method, according to the smoothness index of the power supply power of an independent micro-grid, the cut-off frequency is dynamically adjusted, and the output power of the micro-grid is controlled according to the cut-off frequency which is dynamically adjusted. Compared with the prior art, efficient control over the fluctuation range of the power of the micro-grid can be achieved, and the operation stability of the micro-grid is improved.

Description

technical field [0001] The present invention relates to the field of microgrid technology, in particular to a method for determining the cutoff frequency of a hybrid energy storage microgrid system and an output power control method. The hybrid energy storage microgrid system utilizes high power density energy storage equipment and high energy storage density energy storage The equipment respectively stabilizes the power after frequency division by the cutoff frequency. Background technique [0002] Good environmental and economic benefits have made microgrids more and more aroused the interest of the academic community and received extensive attention from cross-fields. However, due to the existence of distributed power sources in the microgrid, the control strategy and operation strategy of the microgrid are very different from the traditional power system. Moreover, judging from the current power structure, distributed power is still dominated by uncontrollable renewable...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing hybrid energy storage microgrid system in terms of output power amplitude fluctuations and poor adaptability caused by using the exhaustive method to determine the filter cut-off frequency, and to provide a hybrid energy storage The method for determining the cutoff frequency of the microgrid system filter and the method for controlling the output power, using the empirical mode decomposition technology to obtain the best cutoff frequency for high and low frequency division of the output power on the power supply side, and then realizing the efficient control of the microgrid power fluctuation range, Improve the stability of microgrid operation

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