Control method based on hybrid energy storage voltage source inverter (VSI) stabilizing microgrid power fluctuation

Abstract

The invention discloses a control method based on a hybrid energy storage voltage source inverter (VSI) stabilizing microgrid power fluctuation. A hybrid energy storage system two-stage energy management method is designed. The method exploits the advantages, to the full, that according to a super capacitor, the power density is high, and charge and discharge cycle life is long; the super capacitor serves as system first stage energy storage stabilizing the microgrid power fluctuation preferentially; a distribution grid serves as second stage energy storage during grid connected operation; the super capacitor terminal voltage is stabilized in the range of a charging and discharging limited value by controlling the tie line power, and the PCC point bus voltage changes in an allowed range; a battery serves as second stage energy storage during island operation, the charging and discharging number of the battery is decreased through the buffering effect of the super capacitor, and the service life of the battery is prolonged; when the super capacitor reaches a charging and discharging warning value, the battery is accurately controlled to output constant power so as to adjust the super capacitor terminal voltage into a normal value. The effectiveness of the method is verified through simulation results.

Description

technical field [0001] The invention relates to a control method based on hybrid energy storage VSI (voltage source inverter, voltage source inverter) to stabilize microgrid power fluctuations, which belongs to microgrid energy storage technology. Background technique [0002] Connecting distributed power sources, loads, and energy storage devices together and operating in the form of a microgrid can give full play to the performance of distributed power sources and improve the ability of the grid to accept renewable energy. Affected by natural conditions, the output of renewable energy such as wind power and photovoltaics has great intermittent and randomness, which has a negative impact on the power quality and stable operation of the microgrid. When the micro-grid is connected to the grid, the power fluctuation of the intermittent micro-power source will cause the voltage fluctuation of the common connection point, which threatens the normal operation of the load and each...

AI Technical Summary

Problems solved by technology

When the micro-grid is running in an isolated island, the power fluctuation of the intermittent micro-power supply will cause the battery energy storage device to be in a state of frequent charge and discharge, which will greatly reduce the service life of the battery and increase the cost of micro-grid operation

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