Abstract: Aiming at the problem that PV power station with the control strategy of photovoltaic virtual synchronous generator（PVVSG）participating in power system primary frequency control,and considering the partial shadow conditions,an active power reserve PV-VSG control strategy based on the adaptive virtual inertia is proposed. The particle swarm optimization algorithm is used to realize the maximum power point tracking and de-loading operation of PV array for grid frequency regulation under partial shadow conditions,and the virtual inertia is regulated adaptively according to the characteristics of grid frequency under different stages in the variation process,so that the frequency overshoot can be reduced and the recovery speed can be accelerated. Furthermore,in order to reasonably distribute the active power among PV-VSGs in the power plant under frequency regulation mode,an active power distribution strategy based on the equal adjustable capacity ratio is adopted,which makes each PV unit in the plant has the same active power margin for frequency regulation,so the over-regulation problem of some PV units can be avoided. Finally,simulation analyses are carried out by taking a 10 MW solar power plant participating in primary frequency regulation as an example to verify the effectiveness of the proposed control strategy.