Optimal Microgrid–Interactive Reactive Power Management for Day–Ahead Operation

Martha N Acosta,Manuel A Andrade,Danijel Topić,Francisco Gonzalez-Longatt

doi:10.3390/en14051275

Martha N Acosta, Manuel A Andrade + Show 2 more

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https://doi.org/10.3390/en14051275

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Abstract

The replacement of conventional generation sources by DER creates the need to carefully manage the reactive power maintaining the power system safe operation. The principal trend is to increase the DER volume connected to the distribution network in the coming years. Therefore, the microgrid represents an alternative to offer reactive power management due to excellent controllability features embedded in the DER, which enable effective interaction between the microgrid and the distribution network. This paper proposes a microgrid–iterative reactive power management approach of power-electronic converter based renewable technologies for day-ahead operation. It is designed to be a centralised control based on local measurements, which provides the optimal reactive power dispatch and minimise the total energy losses inside the microgrid and maintain the voltage profile within operational limits. The proposed optimal-centralised control is contrasted against seven local reactive power controls using a techno-economic approach considering the steady–state voltage profile, the energy losses, and the reactive power costs as performance metrics. Three different reactive power pricing are proposed. The numerical results demonstrate the optimal microgrid–interactive reactive power management is the most suitable techno-economic reactive power control for the day–ahead operation.

Highlights

The reactive power is one main factor in ensuring the voltage remains within safe limits across the whole power system
The seven local reactive power managements, as well as the proposed optimalcentralised reactive management, were assessed using the MV distribution Benchmark system developed by the International Council on Large Electric Systems Task Force C6.04, which is fully described in the report title “Benchmark Systems for Network Integration of Renewable and Distributed Energy Resources” [21]
This paper answers the research question: can a microgrid grid-interactive be used as an enhancement mechanism of reactive power regulation for smart converters based renewable technologies and provide better techno-economic performance using a centralised control approach than a local control strategy? By performing a techno-economic assessment of the optimal microgrid-interactive reactive power management strategy and seven local reactive power control strategies

Summary

Introduction

The reactive power is one main factor in ensuring the voltage remains within safe limits across the whole power system. The voltage-reactive power dependency must carefully be controlled, especially when the power system is experiencing a fast and exceptional transition to become a zero-carbon industry [1]. The continuously evolving power system is mainly involving the replacement of conventional generation sources by low and zero-carbon energy sources, known as DER. The main change is yet to come when fossil fuels are no longer used to produce electricity. It raises the need for new energy sources to provide reactive power support at transmission and the distribution level

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Conclusion