*4.4. Overall Execution Procedure*

For the PV system, the overall flow diagram of TRL to achieve MPPT under PSC is illustrated in Figure 4. Firstly, the original searching space of output voltage is decomposed into a four-layered smaller searching subspace within its corresponding lower bounds and upper bounds. Then, the knowledge transfer between the new task and the past task is implemented according to their similarity of weather conditions. Furthermore, TRL can update the knowledge matrices via multiple explorations and exploitations in the scheduled iterations. At last, for the PV system, the optimal solution (optimal output voltage) can be obtained to achieve MPPT under PSC.

**Figure 4.** Overall flow diagram of TRL for MPPT. PSC: Partial Shading Conditions.
