## 5 Simulation Verification
Taking the POD installed on the RSC side of the doubly-fed fan as an example, the results of the POD controller parameters of the traditional particle swarm algorithm and the improved particle swarm algorithm are shown in Table 5. \begin{table}
\begin{tabular}{c c c c c} \hline
**Before the Wind Storage System Is Connected to the Grid** & \multicolumn{3}{c}{**After the Wind Storage System Is Connected to the Grid**} \\ \hline
**Eigenvalue** & _f/_Hz** & \(\xi\) & **Eigenvalue** & _f/_Hz** & \(\xi\) \\ \hline \(-0.249\pm 8.473\) & 1.286 & 0.0296 & \(-0.171\pm 6.477\) & 1.031 & 0.0264 \\ \(-0.180\pm 7.542\) & 1.176 & 0.0187 & \(-0.138\pm 7.391\) & 1.176 & 0.0187 \\  & / & / & \(-0.216\pm 8.551\) & 1.361 & 0.0253 \\  & / & / & \(-0.158\pm 7.623\) & 1.213 & 0.0207 \\ \hline \end{tabular}
\end{table} 
Table 4: Influence of wind storage system on LFO of power system under weak damping. Figure 12: Characteristic values of wind storage system before and after grid connection. The doubly-fed fan and energy storage are connected to the grid at the same point, and a small load disturbance is added at the 4 s, and the original load is restored at the 8 s. According to the optimization parameters, the parameters of the POD control part are adjusted, and the active power output of the wind storage system is observed, as shown in the figure. As the ESS has not reached its maximum output power, the calculation of its overshoot should take the maximum output power as a reference value, so it does not affect the system stability. Moreover, the ESS can increase the output to make up for the power shortage caused by the sudden increase of the system load, accelerate the power angle oscillation amplitude of the synchronous machine to approach zero, and significantly enhance the system stability. As can be seen from Figure 13, under the controller parameters obtained by the two algorithms, the wind storage output of the system will increase instantaneously when it is disturbed. In the traditional PSO algorithm, the amplitude of wind storage output change is large, the power fluctuation is more obvious, and the flat power fluctuation rate is slower. The improved PSO algorithm makes the amplitude of wind storage output change small, the economy is better, and the flat power fluctuation speed is faster. The effectiveness of the proposed controller and optimization algorithm in power regulation is verified. The Figure 14 shows the power angle change curve of a single synchronous machine under the POD control of the original load and the POD control with POD control and parameter optimization at the 4 s and the POD control of the original load at the 4 s. Due to the limited power adjustment effect of the fan without POD control, the power angle of the generator changes significantly, and the amplitude oscillation occurs, and even leads to the system dissolution; Under the traditional PSO algorithm, POD control can reduce the oscillation amplitude, increase the oscillation frequency, and finally maintain the stability of the power angle. Under the improved PSO algorithm, POD control can further reduce the oscillation amplitude, the oscillation frequency is higher, and the ability to quickly restore the power angle is stronger. The effectiveness of the proposed controller and optimization algorithm in maintaining the stability of the power angle is verified. \begin{table}
\begin{tabular}{l l l l l l} \hline  & \(\mathbf{K_{\text{POD}}}\) & \(\mathbf{T_{\text{d1}}}\) & \(\mathbf{T_{\text{d2}}}\) & \(\mathbf{T_{\text{d3}}}\) & \(\mathbf{T_{\text{d4}}}\) \\ \hline Traditional PSO algorithm & 13.89 & 0.86 & 0.023 & 0.12 & 0.05 \\ Improved PSO algorithm in DFIGs & 13.97 & 0.67 & 0.036 & 0.22 & 0.05 \\ Improved PSO algorithm in ESS & 13.95 & 0.69 & 0.038 & 0.28 & 0.06 \\ \hline \end{tabular}
\end{table} 
Table 5: Comparison of POD parameters. Figure 13: Comparison of the active output of the wind storage system using POD and NIPSO POD controller. Table 6 is comparison of System Time Domain Performance Indexes under Three Controls.