The rapid expansion of electric vehicle adoption presents distribution system operators with a dual challenge: accommodating growing charging demand while maintaining voltage stability and minimizing energy losses. A new optimization framework addresses this by determining optimal locations and sizes for both EV charging stations and shunt capacitors within radial distribution systems.
Researchers developed a hybrid algorithm merging Gray Wolf Optimization with Cuckoo Search methodology to balance exploration and exploitation of the solution space. The approach maximizes Net Present Value while simultaneously reducing active power losses, improving voltage profiles, and lowering expected interruption costs—a critical reliability metric in distribution planning.
Validation on IEEE 33-bus and 118-bus test systems demonstrated substantial improvements. Active power losses decreased by 34.45% and 31.08% respectively, translating to annual energy loss cost reductions of $35,268 and $209,153. Expected interruption costs fell by $14,030 to $48,699 annually. Most significantly, the integrated approach achieved net annual profits of $27,049 and $221,281 on the respective networks.
The framework incorporates Vehicle-to-Grid (V2G) capability, enabling bidirectional power flow between charging stations and the distribution network. This flexibility allows charging stations to support the grid during peak demand periods while absorbing excess generation during off-peak hours. The aggregated modeling approach treats multiple EVCSs as a coordinated resource, enhancing system reliability and enabling more sophisticated demand response strategies.
Shunt capacitor placement complements EVCS integration by providing reactive power support, reducing voltage drops and losses while improving power factor. The combined optimization ensures that both components work synergistically rather than independently.
These findings suggest that distribution planners should adopt integrated planning approaches that simultaneously consider EV infrastructure and reactive power compensation. Such holistic strategies unlock significant economic and technical benefits compared to sequential or isolated planning methods, supporting cost-effective modernization of distribution systems in the electrification era.
