System Level Protection System and Method for Sub/Super Synchronous Resonance/Oscillation

Abstract

The invention discloses a sub / super synchronous resonance / oscillation system-level protection system and method, wherein the system includes: a centralized protection coordinator and multiple distributed protection relays, and each distributed protection relay of the multiple distributed protection relays The protection relay collects the three-phase voltage and current of the corresponding device port, obtains the time domain waveform of the voltage and current, obtains the sub / super synchronous impedance, and triggers the local Protection action; the centralized protection coordinator obtains the sub / super synchronous impedance of the wind farm measured by multiple distributed protection relays, so as to obtain the sub / super synchronous aggregate impedance of the system according to the preset circuit topology, and in the sub / super synchronous When the aggregate impedance does not meet the stability conditions, obtain the best cut-off strategy to generate a system-level protection signal. The system can provide accurate, fast and reliable protection measures, thereby effectively improving the stability and security of the system to reduce losses drop to lowest.

Description

technical field [0001] The invention relates to the technical field of power system protection, in particular to a sub / super synchronous resonance / oscillation system-level protection system and method. Background technique [0002] In recent years, renewable energy power generation (such as wind power, photovoltaic power generation, etc.) has developed rapidly. However, the grid connection of renewable energy power generation has brought new challenges to the stable operation of the power system. For example, the sub / supersynchronous resonance / oscillation caused by the interaction between the converter-based wind turbine and the AC grid may cause a large area of ​​wind turbines to go off-grid, and even seriously threaten the stable operation of power equipment and the entire system. [0003] For the sub / supersynchronous resonance / oscillation protection of the steam turbine generator set, most of the related technologies use the shaft speed as the input, which cannot be appli...

AI Technical Summary

Problems solved by technology

However, the protection methods based on voltage, current or power still have major defects, because these quantities cannot accurately measure the impact of a certain wind turbine or a wind farm on the entire system, and sub / super synchronous Resonance / oscillation is the dynamic behavior of the whole system, so the protection should also be based on the whole system. Only using local information to judge the protection behavior has poor accuracy, low reliability and safety, and needs to be improved urgently

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