Application of Dynamic V Ar Controllers for Increasing Solar Hosting Capacity in Distribution Grids

Distribution grid with high solar penetration can cause huge voltage fluctuations due to sudden change of solar generation. This causes power quality issues, customer dissatisfaction and risks customer equipment. As a result, voltage control becomes extremely important since utilities have to keep the service voltage between 114V and 126V. Conventional electromechanical voltage control devices like Load Tap Changers (LTCs) and Switched Capacitor Banks (SCBs) do not act fast enough to mitigate the voltage fluctuations cause by solar. New methods are being suggested to use smart inverters going forward, but most inverters are still legacy inverters in the field. This paper introduces a novel approach by using Dynamic V Ar Controllers (DVC) to regulate the voltage by injecting reactive power dynamically. A pilot project at Hawaiian Electric has shown that with 30 DVCs distributed on a feeder with 37% (1.03 MW
_PV
) PV penetration, DVCs reduce feeder voltage fluctuations up to 1.54%(1.85V) which could increase the PV hosting capacity of the circuit from 37% (1.03 MW
_PV
) to 99% (2.7 MW
_PV
).