## 4 Simulation and Experimental Results  
### Simulation and Experimental Equipment  
The main pieces of simulation and experimental equipment are a model and a controller of a PV power system built using a PC host as MATLAB R2012a Simulink (MathWork, New York, NY, USA). The host specifications are Intel core i7-3770 CPU 3.4 Ghz (Intel, New York, NY, USA) and 8 G memory (Intel, Santa Clara, CA, USA). The specifications of the PV panel are shown in Table 2; the maximum power is 17 W, the open-circuit voltage is 21.24 V, and the maximum operating point voltage is 16 V.  
\begin{table}
\begin{tabular}{c c} \hline
**Specific Parameter** & **Value** \\ \hline Maximum Power \(P_{max}\) & 17 (W) \\ Maximum Power Voltage (\(V_{mp}\)) & 16 (V) \\ Maximum Power Current (\(I_{mp}\)) & 1.06 (A) \\ Open circuit Voltage (\(V_{OC}\)) & 21.24 (V) \\ Short circuit Current (\(I_{SC}\)) & 1.2 (A) \\ Operating Cell temperature Range & –40 \({}^{\circ}\)C–85 \({}^{\circ}\)C \\ \hline \end{tabular}
\end{table}
Table 2: Specific parameters of the proposed PV array (at solar radiation of 1 kW\(\cdot\)m\({}^{-2}\) and a cell temperature of 25 \({}^{\circ}\)C).  
Figure 5: Algorithm flowchart of FOICM.  
Figures 6a and 7a show that in the case without a voltage detector, as the MPPT continues all the while, the MPPT is still implemented in steady state, but the power and voltage are disturbed near the MPP, causing power loss. As shown in the enlarged view of Figures 6b and 7b, the power and voltage oscillation is relatively small and almost stable under the control of a voltage detector. The variance in dynamic error value can be observed in Figure 8; as the voltage detector is used, the MPPT is stopped when the dynamic error is smaller than the set value, so the duty cycle is fixed. Therefore, the PV  
Figure 8: (**a**) \(\varphi_{1}\) simulation comparison diagram of voltage detector at constant cell temperature; (**b**) \(\varphi_{1}\) simulation comparison diagram of voltage detector at constant cell temperature in the range of 0.8 s to 1.2 s.  
Figure 7: (**a**) Voltage simulation comparison diagram of voltage detector at constant cell temperature; (**b**) voltage simulation comparison diagram of voltage detector at constant cell temperature in the range of 0.8 s to 1.2 s.  
Figures 9 and 10 show the power oscillation and loss caused by continuous MPPT in the case without a voltage detector. Figures 9b and 10b show that the oscillation amplitude is reduced and almost stable under the control of a voltage detector. Figure 11 shows the real-time dynamic error detection. The MPPT is stopped when the error amount is smaller than the set value. It is obvious that the power and voltage oscillations are reduced. When the cell temperature changes at 2 s, the MPPT is implemented immediately as the error amount increases, and the MPPT is stopped when the maximum power is tracked. Thus, the PV panel supplies to the load at maximum power point, and the steady-state response is good. From the steady-state responses of MPPT, it can be seen that about 0.2 vibration amplitude can be suppressed with control action. Therefore, about 4% of the steady-state vibration energy can be saved. The system efficiency can be increased and the lifetime of electronic modules can be prolonged.