*4.2. Constraints*

(1) DG installation capacity constraint

Light intensity, temperature, wind speed are all uncertain factors. If too much of this type of DG is added to the distribution network, the power quality of the system will be degraded. It is therefore necessary to limit the installation capacity of PV and WG.

$$\begin{cases} \ S\_{\rm pv,i} \le S\_{\rm pv,max}, i \in N\_{\rm pv} \\\ S\_{\rm wg,i} \le S\_{\rm wg,max}, i \in N\_{\rm wg} \end{cases} \tag{18}$$

where *S*pv,*<sup>i</sup>* and *S*wg,*<sup>i</sup>* are respectively the PV installation capacity at the *i*-th PV candidate node and the WG installation capacity at the *i*-th WG candidate node; *S*pv,max and *S*wg,max are respectively the maximum installation capacity of PV and WG.
