Scenario-based Unit Commitment Optimization for Power System with Large-scale Wind Power Participating in Primary Frequency Regulation

Abstract

Continuous increase of wind power penetration brings high randomness to power system, and also leads to serious shortage of primary frequency regulation (PFR) reserve for power system whose reserve capacity is typically provided by conventional units. Considering large-scale wind power participating in PFR, this paper proposes a unit commitment optimization model with respect to coordination of steady state and transient state. In addition to traditional operation costs, losses of wind farm de-loaded operation, environmental benefits and transient frequency safety costs in high-risk stochastic scenarios are also considered in the model. Besides, the model makes full use of interruptible loads on demand side as one of the PFR reserve sources. A selection method for high-risk scenarios is also proposed to improve the calculation efficiency. Finally, this paper proposes an inner-outer iterative optimization method for the model solution. The method is validated by the New England 10-machine system, and the results show that the optimization model can guarantee both the safety of transient frequency and the economy of system operation.

Frequency-constrained Co-planning of Generation and Energy Storage with High-penetration Renewable Energy

“…Constraints (46) and (78) are utilized to guarantee enough frequency response power, while the constraint (79) requires enough system inertia to limit ROCOF. The equivalent frequency parameters can be calculated through (12), (17), and (19). Note that all equivalent frequency parameters just depend on the frequency-support states if settling a fixed unbalanced power.…”

“…Furthermore, a stochastic UC model that incorporates both SGs and grid-connected inverters to obtain synthetical frequency responses is proposed in [16] to investigate the dynamic frequency in low-inertia power systems. Considering the large-scale wind power participating in frequency responses, [17] proposes a UC model with respect to coordination of steady state and transient state based on an inner-outer iterative optimization method. However, frequency responses from hydro units are rarely considered in existing studies, whereas a fast inertial response and PFR can be timely obtained through hydro turbines and governors [18].…”

Data‐driven lumped dynamic modelling of wind farm frequency regulation characteristics

“…Reducing dependence on fossil energy and increasing the development and utilization of renewable clean energy are gradually becoming the direction of energy development and transformation in today's world. The uncertainty of wind speed leads to the fluctuation and randomness of wind power, which makes the grid with a high proportion of wind power facing the challenge of frequency instability [1][2][3][4]. Therefore, many countries have clearly proposed that wind farms should have their own ability to participate in the system frequency regulation [5].…”

Virtual Inertia Estimation Method of DFIG-based Wind Farm with Additional Frequency Control

“…D UE to cleanliness, safety, and adequacy, wind power generation has experienced rapid development in the past decades [1]- [3]. Doubly-fed induction generator (DFIG) is one of the most commercialized wind turbines (WTs) with good performance in integrating intermittent wind power, but its converter control makes the rotor speed decoupled with the system frequency [3].…”

“…D UE to cleanliness, safety, and adequacy, wind power generation has experienced rapid development in the past decades [1]- [3]. Doubly-fed induction generator (DFIG) is one of the most commercialized wind turbines (WTs) with good performance in integrating intermittent wind power, but its converter control makes the rotor speed decoupled with the system frequency [3]. With the continuous growth of DFIG-based wind farms, the total equivalent rotary inertia of the system is passively decreased, and the high penetration itself also generates additional disturbance because of the time-varying output.…”