This paper presents a case of photovoltaic system applying stabilizers in a 16-machine power system to alleviate inter-area power oscillations. As PV power station can exchange both active and reactive power with power grid, stabilizers attached to a PV system is able to function to suppress power system oscillations via regulation of active or/and reactive power. Thus PV system based stabilizers can be classified into two types, active stabilizer and reactive stabilizer. In the paper, firstly mathematical model of PV power station installed in a multi-machine power system is described. The damping function of stabilizers attached to the PV system is analyzed. Then a case of applying PV generation stabilizers in multi-machine power system is presented. Both the active and reactive stabilizer attached to the PV system is designed and their performance to suppress inter-area power oscillations is compared.