Volt-PF Control Mode for Distribution Feeder Voltage Management Under High Penetration of Distributed Energy Resources

Abstract

Voltage-power factor (Volt-PF) control is introduced and compared with the popular voltage-reactive power (Volt-VAr) control for feeder voltage management. An inherent limitation of the Volt-VAr control is that the reactive power (Q) demanded from the distributed energy resources (DERs) is only a function of the terminal voltage and not the DER active power (P). This leads to an unfair allocation of the burden of Q support among the DERs, in the sense that those DERs generating lower P, and hence contributing less to overvoltage issues, may be required to provide more than their share of Q support, and operate at a very low power factor (PF). The proposed volt-PF scheme, where the Q support is inherently a function of both the voltage and P of the DERs, ensures fair allocation of the Q support burden and ensures that all the DERs operate at a high PF (0.9 to 1) The performance of the proposed scheme is validated through extensive static and dynamic simulations on a real, large (8000+ nodes) feeder with very high penetration (>200%) of DERs. The implementation of the proposed scheme in new and existing commercial hardware inverters is described.

Keywords

• Distributed control
• photovoltaic generators
• reactive power control
• volt-VAr control
• voltage regulation