Reducing BESS Capacity for Accommodating Renewables in Subtransmission Systems with Power Flow Routers

TL;DR

This paper demonstrates that integrating power flow routers in subtransmission systems can reduce the required capacity of battery energy storage systems by 15% for renewable energy accommodation, enhancing grid flexibility.

Contribution

It introduces a multi-period optimization model evaluating PFRs' role in reducing BESS capacity needs for renewable integration in subtransmission systems.

Findings

PFRs can reduce BESS capacity by 15%.

The model considers operational constraints and voltage properties.

Numerical simulations validate the effectiveness of PFRs.

Abstract

Widespread utilization of renewable energy sources (RESs) in subtransmission systems causes serious problems on power quality, such as voltage violations, leading to significant curtailment of renewables. This is due to the inherent variability of renewables and the high R/X ratio of the subtransmission system. To achieve full utilization of renewables, battery energy storage systems (BESSs) are commonly used to mitigate the negative effects of massive fluctuations of RESs. Power flow router (PFR), which can be regarded as a general type of network-side controller, has also been verified to enhance the grid flexibility for accommodating renewables. In this paper, we investigate the value of PFR in helping BESSs for renewable power accommodation. The performance of PFR is evaluated with the minimum BESS capacity required for zero renewable power curtailment with and without PFRs. The operational constraints of BESSs and the terminal voltage property of PFRs are considered in a multi-period optimization model. The proposed model is tested through numerical simulations on a modified IEEE 30-bus subtransmission system and a remarkable result shows that 15% reduction of BESS capacity can be achieved by installing PFRs on a single line.