Stochastic Reactive Power Management in Microgrids with Renewables

TL;DR

This paper introduces a stochastic reactive power management scheme for microgrids with renewables, improving voltage stability and reactive power control amid uncertain generation and demand fluctuations.

Contribution

It develops a distribution-free, online reactive control scheme using power injection data and Lagrange multipliers, advancing reactive power management in microgrids.

Findings

Outperforms deterministic schemes in reactive power management.

Effectively tracks solar and demand variations.

Validated on industrial and residential microgrids.

Abstract

Distribution microgrids are being challenged by reverse power flows and voltage fluctuations due to renewable generation, demand response, and electric vehicles. Advances in photovoltaic (PV) inverters offer new opportunities for reactive power management provided PV owners have the right investment incentives. In this context, reactive power compensation is considered here as an ancillary service. Accounting for the increasing time-variability of distributed generation and demand, a stochastic reactive power compensation scheme is developed. Given uncertain active power injections, an online reactive control scheme is devised. This scheme is distribution-free and relies solely on power injection data. Reactive injections are updated using the Lagrange multipliers of a second-order cone program. Numerical tests on an industrial 47-bus microgrid and the residential IEEE 123-bus feeder corroborate the reactive power management efficiency of the novel stochastic scheme over its deterministic alternative, as well as its capability to track variations in solar generation and household demand.