For local power grids with a high proportion of renewable energy

the uncertainty of renewable energy output will lead to the need for more flexible resources in the region. Therefore

a zonal optimization method for flexible ramping ancillary services is proposed to ensure that sufficient ramping flexibility. Firstly

the correlation between ramping

frequency regulation

and reserve ancillary services was analyzed

and a ramping product suitable for the Chinese electricity market was designed from three aspects as follows: functional positioning

zonal requirements

and trading mechanism. Secondly

renewable energy was taken as ramping capacity provider

and the uncertainty of local net load and N−1 faults was taken into account

so that a joint optimization model was formulated. Finally

through numerical examples

the results show that the proposed model can effectively optimize the allocation of flexible ramping capacity from various resources.