Method and device for checking reactive switching strategy of extra-high voltage alternating current transformer substation

The invention discloses a method and a device for checking a reactive switching strategy of an extra-high-voltage alternating-current transformer substation. The method comprises the following steps: determining a steady-state overvoltage upper limit and a reactive switching capacity upper limit of the extra-high-voltage alternating-current transformer substation; determining a reactive switching strategy of the main transformer of the transformer substation according to the reactive exchange capacity upper limit; according to a reactive switching strategy, through a steady-state overvoltage upper limit and a reactive exchange capacity upper limit, the steady-state overvoltage of the extra-high voltage transformer substation in an extreme mode is calculated, and the steady-state overvoltage is adjusted through related reactive switching measures; carrying out alternating-current and direct-current fault and power fluctuation fault transient stability simulation on the extra-high voltage alternating-current tr