The invention discloses a series-parallel
system virtual inertia optimal configuration method and
system, and the method comprises the steps: initializing parameters, taking a
system spectrum intercept as an optimization target, and constructing a
virtual inertia optimization model in combination with a minimum
damping ratio constraint, a total
virtual inertia constraint and a single-
machine virtual
inertia time constant constraint; based on the obtained virtual
inertia optimization model, forming a
state space matrix corresponding to the k-step parameter, and performing eigenvalue
decomposition to obtain first-order sensitivity and second-order sensitivity of eigenvalues; constraining the second-order sensitivity of the obtained characteristic value, establishing a
local linear optimization model containing curvature constraint, and obtaining an optimal perturbation direction; adjusting the step length according to a
backtracking line search rule, and calculating candidate parameters until a descending condition is met or the maximum
backtracking frequency is reached; and updating the parameters, and outputting the optimal parameters after the parameters converge. Frequency safety and small interference stability are both considered, convergence efficiency is improved, the adaptive step length and the
linearization model are adapted to an actual
power grid, and auxiliary service cost is reduced.