Control method for participating in primary frequency modulation of power grid by battery energy storage power supply

The invention relates to a control method for participating in primary frequency modulation of a power grid by a battery energy storage power supply. Primary frequency modulation is performed jointlyby a virtual inertia frequency modulation mode and a virtual droop frequency modulation mode, respective frequency modulation numerical valves are allocated to the virtual inertia frequency modulationmode and the virtual droop frequency modulation mode according to an allocation proportional coefficient, and (a1+a2) is equal to 1; at an initial moment, a1 is equal to 1, and a2 is equal to 0; in the time from a frequency disturbance initial moment to a frequency deviation maximum value, the virtual inertia frequency modulation is taken as a main, the virtual droop frequency modulation mode isassistant, namely, a1 is larger than a2; at the moment of the frequency deviation maximum value, a1 is equal to a2 and also is equal to 0.5; in the time from the moment of the frequency deviation maximum value to primary freque