Solar PV Siting Impacts on Annual Load Interruption Cost Due to Voltage Sags in Industry

Abstract

Voltage sags are detrimental to the industry as most of their machinery is susceptible to sag-induced interruptions, and a very high cost is associated with it. Due to the high cost, the industry employs specialized devices like STATCOM to help protect the equipment from disconnecting. Solar PVs (with associated inverters), which are being popularly introduced in industrial distribution systems due to their advantage of reducing reliance on grid energy, can also function as a STATCOM and help reduce the impact of voltage sag. Typically PV inverters are placed inside a distribution network by only considering the energy advantage. However, placement becomes essential to reduce the load disconnection cost due to voltage sag. Thus, this paper presents a study to find how the location of PV inside an industrial distribution network affects the annual load interruption cost. Dynamic simulations are conducted on a realistic IEEE 41 bus industrial distribution network while considering the dynamic control of the PV inverters and disconnection criteria of industrial loads. A pseudo-random sampling method is utilized, and the load disconnection cost results for various PV inverters placements are analyzed. Results show that the cost of disconnection is sensitive to the specific placement of PV. This study finds that a single 4.5 MW PV can reduce the load disconnection cost by as much as 12% if placed appropriately inside an 18.5 MVA industrial distribution network.