Risk-Limiting Real-Time Economic Dispatch in a Power System with Flexibility Resources

Abstract

The integration of numerous intermittent renewable energy sources (IRESs) poses challenges to the power supply-demand balance due to the inherent intermittent and uncertain power outputs of IRESs, which requires higher operational flexibility of the power system. The deployment of flexible ramping products (FRPs) provides a new alternative to accommodate the high penetration of IRESs. Given this background, a bi-level risk-limiting real-time unit commitment/real-time economic dispatch model considering FRPs provided by different flexibility resources is proposed. In the proposed model, the objective is to maximize the social surplus while minimizing the operational risk, quantified using the concept of conditional value-at-risk (CVaR). Energy and ramping capabilities of conventional generating units during the start-up or shut-down processes are considered, while meeting the constraints including unit start-up/shut-down trajectories and ramping up/down rates in consecutive time periods. The Karush–Kuhn–Tucker (KKT) optimality conditions are then used to convert the bi-level programming problem into a single-level one, which can be directly solved after linearization. The modified IEEE 14-bus power system is employed to demonstrate the proposed method, and the role of FRPs in enhancing the system flexibility and improving the accommodation capability for IRESs is illustrated in some operation scenarios of the sample system. The impact of the confidence level in CVaR on the system operational flexibility is also investigated through case studies. Finally, a case study is conducted on a regional power system in Guangdong Province, China to demonstrate the potential of the proposed method for practical applications.

Modern Power System Dynamics, Stability and Control

“…A bi-level risk-limiting real-time unit commitment/real-time economic dispatch model with flexible ramping products (FRPs) is proposed in [20] by Lin et al The model provides a new alternative to accommodate the high penetration of numerous intermittent renewable energy sources (IRESs). The modified IEEE 14-bus power system is employed to demonstrate the proposed method and the role of FRPs in enhancing the system.…”

Reviewing the impact of AI on renewable energy efficiency and management

“…Addressing the challenges posed by intermittent renewable sources is crucial for the integration of renewable energy into the grid. The intermittent nature of renewable energy sources, such as wind and solar power, leads to fluctuations in power output, posing challenges for grid stability and reliability (Kumar et al, 2022;Lin et al, 2019;Kies et al, 2016). These challenges include variability, uncertainty, and intermittency, which can affect the operational flexibility of power systems and the balancing of power generation (Lin et al, 2019;Kies et al, 2016).…”

“…The intermittent nature of renewable energy sources, such as wind and solar power, leads to fluctuations in power output, posing challenges for grid stability and reliability (Kumar et al, 2022;Lin et al, 2019;Kies et al, 2016). These challenges include variability, uncertainty, and intermittency, which can affect the operational flexibility of power systems and the balancing of power generation (Lin et al, 2019;Kies et al, 2016). The integration of renewable power sources, which are not dispatchable but intermittent, also presents challenges for power system operation (Johnson et al, 2023;Dimoulkas et al, 2017).…”

Research on Renewable-Energy Accommodation-Capability Evaluation Based on Time-Series Production Simulations

“…In the research on ensuring the grid's balance, while renewable energy is connected to the grid [20,21], it started from reducing the intermittency and volatility of renewable energy itself in order to solve the problems that affect the security and stability of the grid system when renewable energy is connected to the grid. In [22], the power supply and demand balance when intermittent renewable energy was connected to the grid is ensured by combining different elastic resources. In [23], a multi-period optimal scheduling scheme was proposed to solve the uncertainty problem of renewable energy generation and improve the stability of renewable energy grid connection.…”