Satellite timing and management network based micro power grid islanding detection method and system

Abstract

The invention provides a satellite timing and management network based micro power grid islanding detection system. The satellite timing and management network based micro power grid islanding detection system comprises a central controller; the central controller is used for obtaining pulse per second signals through satellite timing and collecting voltage signals from a common connection point between a large power grid and a micro power grid, wherein the pulse per second signals and the international standard time maintain synchronization; the central controller is communicated with a grid connected inverter control unit. According to the satellite timing and management network based micro power grid islanding detection method and system, the periodic disturbance on the output current of a grid connected inverter does not need to be performed at any time, the grid connected inverter is only informed that output power factors change through the micro power grid management network when the change of a relative phase of the voltage forward direction zero crossing point of the common connection point is large and the islanding is deduced, and accordingly a user can further confirm whether the islanding really occurs or not and accordingly the effect on the power quality of the islanding detection by the satellite timing and management network based micro power grid islanding method is small.

Description

technical field [0001] The invention relates to the field of microgrid systems, in particular to a microgrid island detection method and system based on a satellite timing and management network. Background technique [0002] The isolated island refers to the disconnection of the microgrid from the public grid due to the failure of the power grid, and the distributed power supply in the microgrid continues to supply power to the local load, forming an "island" of power supply. The control mode of the microgrid in the case of grid connection and islanding is completely different, and the islanding must be detected in time and the control mode should be switched in a timely manner. [0003] At present, most islanding detection methods are to implant an islanding detection algorithm in the grid-connected inverter for islanding detection. During grid-connected operation, the grid-connected inverter sends out a disturbance, and the sampling conversion circuit transmits the volta...

AI Technical Summary

Problems solved by technology

However, this active islanding detection method will complicate the control algorithm of the inverter, and will affect the power quality and even cause system instability due to periodic disturbances in the output of the grid-connected inverter.

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