In order to study the influence of stochastic time delay on the small-signal stability of power system

a method for calculating the sensitivity of eigenvalue to time delay is proposed based on damping torque analysis. By using the method of Gram-Charlier expansion

the probability density function of the real part of critical eigenvalue under stochastic time delay is deduced. The proposed method is fast and simple. Then parameter robust tuning for power system stabilizer(PSS)is conducted considering stochastic time delays of wide-area signals. The 2-area 4-generator system model is developed on the co-simulation platform of cyber-physical power system based on OPNET-MATLAB. The correctness of the calculation method for eigenvalue probability density function is verified through Monte Carlo simulation and the influence of different time delay characteristics on the small-signal stability is analyzed. Finally

the effectiveness of robust design method for PSS is verified in the 2-area 4-generator system.