Algorithm 3.

Main algorithm: Simultaneous optimization (Reconfiguration-Placement)

Step 1: Initialize the first iteration t = 1

Initialize pheromones: ${\tau }_{ij}\leftarrow {\tau }_0\forall i,j=1,\cdots ,n$

Initialize position p

Step 2: For each ant k = 1 to m

Build a cycle $T^k\left(t\right)$ of tie-switches

Update tie-switches

Step 3: Look for a single path from a given node to the source node with excluded open switches

Step 4: Rearrange loads from end-of-branch nodes—save new topology

Step 5: For each ant k = 1 to m

Evaluate the radiality criterion of the new configuration

If the configuration is radial

Exclude the current topology—Goto Step 6

else

Find p position in the current cycle

Evaluate size of the D-STATCOM at the position found and the power flow of network with the D-STATCOM placed at the position found

Step 6: Compute cost function $L^k\left(t\right)$ of $T^k\left(t\right)$

Update the best global solution

Step 7: For each arc $\left(i,j\right)$

Update pheromones ${\tau }_{ij}$ while confining them in $\left[{\tau }_{\min },{\tau }_{\max }\right]$

$t=t+1$

if $t<N{C}_{\max }$

Goto Step 2

else

Stop

Return the best global solution