The application relates to the technical field of
voltage quality monitoring, in particular to a power distribution line
voltage quality real-time monitoring method based on a low-
voltage transformer area topology, which comprises the following steps: based on the historical output power of each distributed photovoltaic in the
power grid topology structure of the low-voltage
transformer area, a probability
density distribution model is established, the distributed photovoltaic is classified, and the weight coefficients of each distributed photovoltaic are quantified, and the typical probability
distribution model corresponding to each category is extracted; the fluctuation range of the output power is divided into multiple
focal element intervals, and a basic trust degree is allocated to the
focal element intervals to establish a
focal element model of photovoltaic output; a probability interval
power flow model is constructed; the probability interval
power flow model is solved to obtain an interval solution of the node
voltage amplitude, an accumulated trust function curve is constructed through evidence theory, and the quality confidence of the node voltage is obtained, so that the voltage quality of the power distribution line is evaluated. The application effectively improves the identification accuracy and early warning response capability of the voltage out-of-limit risk of the power distribution line.