Patent ID: 7957114
Filing Date: 2011-06-07
Classification: H01H

Abstract:
1. A method for triggering a circuit breaker in the event of a short circuit in which a current flowing in a phase conductor is evaluated by comparing the current with a threshold current, and the circuit breaker is triggered if a result of the evaluation reveals a presence of a short circuit, the method comprising: sampling the current at a fixed sampling frequency and digitizing the sampled current to determine digital current values; computing, for a fixed number of the digital current values in direct succession, wavelet coefficients for at least two segmentation levels by way of a wavelet transformation; comparing the absolute value of at least two wavelet coefficients with each other if a last of the digital current values in direct succession is greater than the threshold current; and triggering the circuit breaker if the wavelet coefficient of a higher segmentation level is greater than the wavelet coefficient of a lower segmentation level.