A small hydropower system coping method and device for unplanned island effect

Abstract

The invention discloses a small hydropower system coping method and device for an unplanned island effect. The method includes: after monitoring the failure of the main grid, controlling the circuit breaker on the high-voltage side of the main transformer between the small hydropower system and the main grid to be disconnected, measuring and obtaining the exchange power between the small hydropower system and the main grid, and determining the value of the exchange power If the absolute value is less than or equal to the adjustment limit active power of the electromechanical unit in the small hydropower system, and the reactive exchange power between the small hydropower system and the main grid is less than or equal to the adjustment limit reactive power of the electromechanical unit in the small hydropower system, then the exchange power is obtained Frequency change over-limit time, determine that the frequency change over-limit time is less than the adjustment time of the electromechanical unit of the small hydropower system, then adjust the output power of the electromechanical unit of the small hydropower system according to the conversion power, so as to realize the stable operation of the small hydropower system, which can eliminate The unplanned island effect in the small hydropower system maintains the normal power supply of the small hydropower system to the load.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of micro-grids, and in particular to a method and device for dealing with unplanned islanding effects in small hydropower systems. Background technique [0002] There are many small hydropower installations in my country and they are widely distributed. Because of its small installed capacity, it has accelerated the full development and utilization of hydropower resources, and has been built with low cost. However, sometimes unplanned situations such as failures occur in the main network. The unplanned island effect of the small hydropower grid has affected part of the small hydropower grid, and usually the small hydropower grid cannot adjust the frequency and power in a timely manner. power supply efficiency of the grid. [0003] At present, the only way to eliminate the impact of the unplanned island effect is to disconnect the small hydropower installations, but this will cause power ...

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Problems solved by technology

[0002] There are many small hydropower installations in my country and they are widely distributed. Because of its small installed capacity, it has accelerated the full development and utilization of hydropower resources, and has been built with low cost. However, sometimes unplanned situations such as failures occur in the main network. The unplanned island effect of the small hydropower grid has affected part of the small hydropower grid, and usually the small hydropower grid cannot adjust the frequency and power in a timely manner. power supply efficiency of the grid

[0003] At present, the only way to eliminate the impact of the unplanned island effect is to disconnect the small hydropower installations, but this will cause power outages for the loads in the grid. Frequent sudden power outages will deteriorate the quality of power supply, resulting in shortened load life and product quality. The failure of automation equipment affects the daily life of users, reduces the reliability of electricity consumption by users, and causes waste of water resources, which reduces the efficiency of small hydropower. If the recovery time of the main network is too long, small hydropower will be restarted and connected to the network. The time is too long, resulting in long-term power outages for users

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