Fast volt-VAR control on PV dominated distribution systems

Abstract

This paper investigates the impact of high penetration Photovoltaic (PV) systems on the voltage profile of a distribution feeder. The paper shows that power fluctuations caused by intermittent PV output can affect the operation of volt-VAR devices and cause unacceptable voltage variations on the feeder. The paper also investigates the adoption of a Dynamic VAR Compensator (DVC) to mitigate these impacts. Simulations performed on a prototype feeder indicate that the DVCs will be quite effective in smoothing out even the fast voltage variations caused by cloud cover on the PV systems.

Performance of PV generation feedback controllers: Power factor versus Volt-VAR control strategies

“…For instance, a PV plant output can vary by 90% over a few seconds on a partly cloudy day, as shown in Figure 1.1 [3]. This rapid variation in the amount of power generated by PV systems leads to voltage fluctuations, reverse power flows, voltage and current unbalances, and power losses in both the transmission and distribution systems [4,5]. One of the biggest challenges in the distribution system is to maintain the customer voltage level in its allowed range [6].…”