The invention discloses a converter
transformer saturation protection optimization method based on L-M
algorithm neural network fitting, and the method comprises the steps: initializing
system parameters after a protection device is started; the position state of a
circuit breaker is monitored in real time, and after a closing
signal is detected, instantaneous values of three-phase current and
neutral current of the valve side of the converter
transformer are collected; performing digital filtering
processing on the acquired three-phase current data, and extracting a fundamental component; then calculating a
peak value curve of a fundamental component of each phase, and identifying a fastest attenuation phase; recording the
peak value of the fundamental component and the time required for attenuating from the
peak value to 5%; taking the characteristic quantity
data set as input and output, and training an L-M
algorithm neural
network model based on the
data set; and according to an input characteristic quantity
data set, obtaining an output value through a neural network, querying an inverse
time limit characteristic curve, and delaying a corresponding
operation time to perform a protection action. According to the method, the magnetizing
inrush current and the direct-current magnetic bias are accurately distinguished by quantifying the direct-current magnetic bias, so that the reliability of protection action is improved.