Aggregation Frequency Response Modeling for Wind Power Plants With Primary Frequency Regulation Service

Abstract

High-penetration wind power access to grid requires wind turbine generator (WTG) to provide frequency regulation service. Consequently, the frequency dynamics of wind power plants (WPPs) integrated system are changing; thus, it is necessary to investigate the dynamic frequency response of WPPs. In this paper, an analytical approach for an aggregated frequency response model for WPPs with primary frequency regulation service is presented and validated. First, different operation region of WTGs is fully taken into account, and a low-order wind power frequency response (WPFR) model with combined frequency control is deduced based on small signal analysis theory, which has been given in the form of symbolic transfer function. Afterwards, a system identification (SI) analytical method is proposed to aggregate a multi-machine WPFR model with heterogeneous parameters into a single equivalent model, which is called an aggregated WPFR (AWPFR) model, and this aggregation method is validated by the mathematical proof. Finally, the accuracy and effectiveness of the AWPFR model is verified through comparisons of simulation results obtained from the multi-machine WPFR model, detailed wind power plant (WPP) model and individual WPFR models, and the impact of the WTG parameters on the system frequency characteristics is analyzed and discussed. Such an aggregation model can provide a convenient way to describe the dynamic frequency response of WPPs by avoiding the need for modeling complex transient processes while maintaining a satisfactory level of accuracy.

Inertia Response Coordination Strategy of Wind Generators and Hybrid Energy Storage and Operation Cost-Based Multi-Objective Optimizing of Frequency Control Parameters

“…As reported in the literature [65][66][67][68], first-order dynamic models for the fuel-cell, the diesel generator, the electrolyser, the battery and the ultra-capacitor have sufficient accuracy to simulate dynamic response in frequency deviation analyses. Also, a low order model of the wind generator consists of the aerodynamic characteristic wind turbine, the mechanical part and MPPT unit [69] can be used in the frequency analysis of MGs. The feasibility of the proposed strategy discussed in previous sections with considering nominal parameters given in Table 3; is shown through simulation results.…”

Aggregated Model of Virtual Power Plants for Transient Frequency and Voltage Stability Analysis

“…Fast frequency response analysis is based on the aggregated models, for example, reference [8] proposes a transfer function to aggregate all the synchronous generators and reference [9] proposes a generic transfer function to represent all of generations in the power system. For a more accurate frequency analysis in time domain simulation, reference [10] proposes a model to aggregate the multiple wind machine system into a single wind generator, reference [11] proposes method to aggregate the multiple grid-feeding converter system into a second order model and reference [12] proves that the virtual inertia response of the wind turbine can be aggregated into a similar form of the swing equation.…”

Analytical system frequency response model with virtual synchronous wind turbines

“…In some studies, the frequency response model of VSWTs is derived by taking different WTs operating conditions into consideration [14,15]. Further, a system identification technique is proposed to aggregate multi-machine VSWTs networks [16]. A generic SFR model is also suggested in [17] to incorporate the dynamics of hydro and wind generation units into the traditional SFR model.…”

“…To solve (16), the deviation in the mechanical power of the SG units ΔP sm , and that of the VSG units ΔP vm , must be known. The former, namely the system primary frequency response (PFR), can be expressed as the following function [37]:…”