【摘要】 小波变换可应用于发电机失磁、振荡与短路情况下电气量信号的处理。通过建立系统仿真模型和利用Matlab进行仿真,经过对电流和电压信号的小波分析表明,在正常、失磁和短路及振荡情况下信号变换后的幅值有明显的差别。因此,可以通过合理设置阈值检测信号小波变换后的幅值,就可以准确地区分失磁和短路与振荡情况,使得在发生失磁时迅速发出信号,而在短路及振荡情况下可靠地将保护闭锁。从而为解决发电机失磁保护误动提出了一种途径。更多还原

【Abstract】 The wavelet transform can be used in the electric signal processing under the situations of loss-of-excitation, oscillation and terminal shout-circuit fault of electric power generator. Through the simulation of a model by Matlab, some results are achieved and show that the amplitudes of voltage and current have obvious difference via wavelet transform under different situations of loss-of-excitation, terminal short-circuit and oscillation from the normal condition. Therefore, it’s possible to distinguish the situations of loss-of-excitation, terminal short-circuit and oscillation through presetting the amplitude limits of signals after wavelet transform in order to enable the trip signal immediately to send out when losing excitation only and lock the trip signal when short-circuit and oscillation is happening. It’s a new approach to intend to solve the erroneous operation of loss-of-excitation protection of generator.更多还原