The invention relates to the technical field of power
system inertia evaluation, in particular to a random
mode switching driven power distribution network equivalent
inertia online evaluation method and
system, and the method comprises the steps: carrying out the priori definition of a group of hidden operation
modes based on the equivalent
inertia of a power distribution network, and constructing an unobservable
Markov chain; a double-layer hidden Markov jump
system model is constructed, the bottom layer is an unobservable
Markov chain, and the upper layer is a
continuous dynamic behavior model for describing the power distribution network; on the basis of PMU high-resolution
time sequence disturbance data, deducing the probability of a system maximum probability dominant
operation mode and the probability of each hidden
operation mode; and carrying out multi-mode probability
adaptive weighting on each equivalent inertia
estimation value based on the probability of the dominant
operation mode and each hidden operation mode so as to obtain the equivalent inertia
estimation value of the power distribution
network on line. Through the method, the problem that the equivalent inertia of the power distribution network is difficult to quickly, accurately, dynamically and adaptively assess online under the conditions of high permeability of
new energy and frequent switching of working conditions is effectively solved.