Excitation surge current identification method based on complex wavelet transform

• Main Authors: WANG JIAN, TONG KAIYING, LI JIASHUAN, DONG YUXUAN, CHEN QIAOYONG, LUO PING
• Format: Patent
• Language: Chinese; English
• Published: 23.11.2018
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention discloses an excitation surge current identification method based on complex wavelet transform; the method uses a first order complex Gauss wavelet to process an air drop current on a main transformer power supply side in a power system, thus obtaining a real part and a virtual part corresponding to the complex wavelet transform; on the basis, the method calculates to obtain the phase of the complex wavelet transform; the method uses the product of the virtual part and the phase obtained by the first-order complex Gauss transform as the identification criterion of the excitationsurge current; when ratio between the first two wave peaks of the criterion product is greater than 1.2, the current is determined as the excitation surge current, otherwise the current is determinedas an internal fault current. The method integrally uses the complex wavelet transform amplitude and phase information, and uses the criterion to effectively distinguish the excitation surge current from the fault current unde