Study on the Application of Excitation System PT Breakage and Slow Fuse Logic
To prevent the excitation system from misregulating due to the primary fuse of PT and the primary system ground fault,the sampling voltage of PT break logic basically adopts the line voltage method.The high-voltage primary fuse of the generator outlet PT is a special operating condition.Under this condition,the operating unit has a high risk of false over-excitation tripping.In order to quickly identify the PT slow-fuse fault of the excitation system,some excitation devices add the excitation slow-fuse logic.The PT slow-fuse logic mostly adopts the dual-PT comparison method.Since the PT slow-fuse set value of the excitation system is based on the line voltage,and the logic criterion is based on the phase voltage,there is a conversion relationship between the two base voltages,resulting in the irrationality of the default set value of the excitation system PT slow-fuse on site,which is not conducive to the rapid judgment of PT slow-fuse.Through on-site tests and the derivation of the relationship between the sampling voltage of the excitation system and the excitation display voltage,optimization suggestions are put forward for the PT disconnection,PT slow-fuse logic,and PT disconnection and slow-fuse setting values of the excitation system,providing reference experience for the safe and stable operation of the excitation system.
万方数据
维普
