Hierarchical Control of Utility-Scale Solar PV Plants for Mitigation of Generation Variability and Ancillary Service Provision

TL;DR

This paper introduces a hierarchical control system for utility-scale solar PV plants that enhances ancillary service provision by managing inverter coordination and proactive curtailment, effectively mitigating generation variability without extra resources.

Contribution

The paper presents a novel hierarchical control approach that improves solar PV plant flexibility and grid support capabilities compared to existing methods.

Findings

Over 10 times more effective in reducing generator mileage.

Successfully manages power fluctuations under variable cloud cover.

Verifies efficacy with high-resolution case study data.

Abstract

Renewable energy technologies including solar and wind inevitably play a leading role in meeting the growing demand for a decarbonized and clean power grid. However, these technologies are highly dependent of meteorological conditions of power plant site and the challenge remains on how to cope with their short-term and momentarily variability. This paper presents a hierarchical control system to provide ancillary services from a solar PV power plant to the grid without the need for additional non-solar resources. With coordinated management of each inverter in the system, the control system commands the power plant to proactively curtail a fraction of its instantaneous maximum power potential, which gives the plant enough headroom to ramp up or down power production from the overall power plant, for a service such as regulation reserve, even under changing cloud cover conditions. A case study from a site in Hawaii with one-second resolution solar irradiance data is used to verify the efficacy of the proposed control system. The algorithm is subsequently compared with an alternative control technology from the literature, the grouping control algorithm; the results show that the proposed hierarchical control system is over 10 times more effective in reducing generator mileage to support power fluctuations from solar PV power plants.