The invention discloses a transient
power quality disturbance detection method based on WMM and HATF. The method comprises the following steps: sampling disturbance signals to obtain a sampling sequence; selecting a proper
wavelet basis; determining the maximum
decomposition layer number N by acquiring the minimum frequency of the
signal; and establishing a
mathematical model of an adjustable factor mu according to the
energy distribution characteristics of each
decomposition layer of
wavelet transform, and calculating an adjustment factor of each
decomposition layer according to the model; calculating the threshold
lambda of each decomposition layer; obtaining an adaptive
threshold function of each decomposition layer, and
processing detail coefficients after
wavelet decomposition; performing
wavelet reconstruction on the approximation coefficient and the detail coefficient of each decomposition layer; starting
electric energy quality disturbance detection, locating a
mutation point,solving the modulus maximum value and the position of the modulus maximum value, and the modulus maximum value point is the
mutation point of the
signal; and recording the time and time interval corresponding to the modulus maximum value point, i.e., the starting and ending time and duration of the disturbance. According to the method, the information of the abrupt change position is better reserved while
noise reduction is carried out on the disturbance
signal, and the accuracy of transient disturbance detection under
noise interference is improved.