*4.3. Assessment of Model Accuracy*

To validate the analysis above, a simulation is implemented under two conditions. The transient behaviors of phase-errors are depicted in Figure 17. This figure shows that the phase-errors of proposed PLL and its mathematics model are equal to each other during two step change in phase and frequency. The design procedure based on the mathematics model is reasonable.

**Figure 17.** The transient response of the proposed PLL (solid line) and its mathematics model (dashed line) under +40◦ phase jump (at 0.04 s) and +5 Hz frequency jump (at 0.08 s).
