Operation Modes of the Volt/var Function in Multiple Inverters for Voltage Regulation in Secondary Distribution Networks

Abstract

Volt/var control in inverters has been implemented globally, but the adoption still presents challenges. Issues such as location, participation in the ancillary service, impacts on power quality and the operation of multiple inverters need to be better evaluated. This article analyzes the impacts on power quality of low-voltage systems with photovoltaic generation, comparing different modes of the Volt/var function with grid reconductoring and fixed power factor. The results indicate that Volt/var control can mitigate voltage problems and reduce losses, although the performance of multiple inverters can be unfair. Low-slope curves in the capacitive area can aggravate overvoltages, especially during periods of high solar generation. Reactive power priority mode can solve the problem of inverter unavailability, but can increase active power losses if the energy is not stored.