Integrating battery banks to wind farms for frequency support provision–capacity sizing and support algorithms

The expected high penetration levels of wind energy in power systems require robust and practical solutions to maintain typical conventional systems performance. Wind farms (WFs) positive contribution in eliminating grid frequency deviations is still a grey area, especially when they replace considerable conventional generation capacities. This paper offers a sizing algorithm to integrate storage battery banks (SBs) in WFs to provide feasible power support during frequency events. This algorithm determines the required rated power and capacity of each SB inside a WF according to several constrains, including wind speed (WS) characteristics at WF location. The size of the SB is based on a statistical study for the amounts of rejected wind power, and the events of low wind production. The offered operation algorithm controls the SB charging, discharging, and standby modes based on the acquisition of different dynamic variables, for example, WF output, load demand, and storage cells' state of charge. The operation algorithm aims to mitigate frequency drops and rejected wind power and to maintain the battery lifetime. Both algorithms are applied on a defined sector from a genuine conventional system merged with real WS chronological records at certain locations which are candidates to host WFs. Results reveal the positive influence of SB involvement on frequency excursions clearance; in addition, wasted wind energy is mitigated since wind turbines de-loading techniques are avoided and some rejected wind power is utilized to charge the installed SBs. Precise models are integrated through MATLAB and Simulink simulation environment

Impact of wind farms capacity factor and participation in frequency support – reliability analysis

Expanded integration of wind energy implies technical confronts to maintain system reliability. Thus, comprehensive reliability models for wind turbines and related features are required. Composite and precise wind farms (WFs) reliability analysis includes wind turbine generator (WTG) detailed models besides wind speed (WS) probabilistic variations considering wake effects. This paper is considered as an extension to the proposed multi-state duration sampling model to asses WTG reliability integrated with a comprehensive representation for WF. The paper investigates the impacts of two WTG frequency support operation algorithms on capacity factors and first hierarchical level indices. LOEE is evaluated using a novel method to emphasis the chronological coordination between load and WS attitudes. System and load points’ reliability indices are estimated at moderate penetration levels of wind energy using a simplified technique. Results insure the feasibility of the composite WTG reliability model and provide reasonable indicators for WFs integration influence

Insights on the provision of frequency support by wind power and the impact on energy systems

This paper implements and compares between the key concepts to enable wind power short-term frequency support from electrical and mechanical loads perspectives. Pitch de-loading, kinetic energy extraction and wind turbine (WTG) over-speeding are investigated, where each concept is integrated as a supplementary controller to the conventional controls of WTG. Different patterns of wind speed are examined, step-change and real intermittent of high resolution. The examined aggregated synchronous area has a relatively high wind penetration with frequency support. The overall dynamic inertia of the system is assessed to analyze the impact of the integrated support methods and their key parameters. The coordination between synchronous areas and wind farms, which are interconnected through a multi-terminal high voltage direct current network (MT-HVDC) is examined. A definition of the virtual inertia of MT-HVDC grid is proposed. Results show that pitch de-loading secures support reserve most of the time, and kinetic energy extraction provides sustainable support for a short time, while accelerative de-loading could reach a compromise. The three methods are adaptable with the MT-HVDC holistic frequency support controller, with a small advantage of kinetic energy extraction on the virtual inertia of the MT-HVDC. Matlab/Simulink® is the simulation environment

Effects of regulating the European Internal Market on the integration of variable renewable energy

ABSTRACT: The new proposal for regulating the European Internal Market for Electricity (EIME) can motivate the harmonization of the various National markets. The process of harmonizing the day-ahead markets (DAMs) is at an advanced stage, with an efficiency in the use of interconnectors of 86%. However, the harmonization of both intraday (IDMs) and balancing markets (BMs) is still in its infancy, with an efficiency in the use of interconnectors of 50 and 19%, respectively. The new proposal brings new targets to DAMs, and European countries should make efforts to comply with them. The same is true for IDMs and BMs, but involving more ambitious targets, requiring higher efforts to be accomplished. Both the analysis of the various National markets (according to their compliance with the new proposal for regulating the EIME) and the advantages of the new proposal for key market participants (particularly, consumers, variable renewable generation, and conventional generation) are presented. The analysis indicates that the proposal contributes to a potential increase of the general welfare of market participants. However, some aspects of the proposal can negatively affect the revenue obtained from the National markets, notably for variable renewable generation and conventional generation. This article is categorized under: Wind Power > Systems and Infrastructure Energy Policy and Planning > Economics and Policy Energy Systems Analysis > Economics and Policy Energy and Development > Economics and Policyinfo:eu-repo/semantics/publishedVersio

Estimation of wind turbines dynamic model parameters using published manufacturer product data

Future wind energy high penetration levels in power systems require robust and practical control algorithms to protect the typical conventional system performance or even improve it. Constructing such feasible control methodologies requires practical, simplified and efficient dynamic simulators for several wind turbines types available in market. This paper offers a procedure to build a simulation tool for modern wind turbines. This simulation box is inspired from the GE 1.5 MW model built in the Simulink library. Three wind turbines types from the top and latest products of three different wind turbines industry tycoons are considered as case studies for the proposed methodology. MATLAB and Simulink are used as simulation environments for the presented experiments

Penetration impact of wind farms equipped with frequency variations ride through algorithm on power system frequency response

Focus of power system engineers is currently directed to the impact of wind power on system frequency. Research efforts concentrate on the ability of wind farms to contribute in the frequency droop events by injecting active power to the grid. This paper presents a detailed analysis for the effect of wind farm connection to a certain power system on the system frequency response. Most of wind farm parameters were considered, namely, the actual wind speeds, wake effects inside the wind farm, the different arrangements of wind turbines inside the wind farm and pitch control mechanism. Moreover, the major data of a h power system were included; different conventional generation technologies and their suitable speed governors. In addition, instant dynamic load variations were implemented. Five case studies were conducted through this system to test the system frequency attitude during normal operation and in case of sudden and large load changes. Three basic values are used to estimate the mentioned impact; the time needed to reach the safe margin after a certain droop, the RMS value of frequency deviation after the fault initiation by a given fixed time span and the maximum frequency drop for each event. All the previously stated studies are performed using MATLAB and Simulink simulations depending on real wind speeds data

Novel wind turbine reliability model-implementation to estimate wind farms capacity credit

The expanded integration of wind energy imposes technical challenges to maintain system reliability. In order to tackle these challenges, comprehensive reliability models for wind turbines and related factors are essential. Proposed algorithm classifies Wind Turbine Generator (WTG) components based on their impact on WTG output. There upon, the WTG has a composite three-state reliability model which aggregates WTG foremost components. The chronological operation conditions of each component is obtained using state duration sampling method. Precise Wind Farms (WFs) reliability assessment requires accurate Wind Speed (WS) forecasting methods which acknowledge WSs propagation through WFs terrains. Thus, WS variations are developed based on Weibull distribution. Offered algorithms are integrated to estimate the capacity factor of some WFs using Monte Carlo simulation method. The implied WS data are recorded in certain locations in Egypt which are candidates to host WFs. The utilized simulation environments are MATLAB and Simulink

Frequency drops mitigation at high wind energy penetration using hydro-pumped storage - capacity sizing

Expected wind energy high penetration levels in power systems require robust and practical solutions to improve typical conventional systems performance or at least maintain it. Wind farms positive contribution in eliminating grid frequency deviations still a grey area, especially, when wind farms replace considerable conventional generation capacities. This paper offers a detailed algorithm to integrate a hydro pumped storage facility to provide power support during frequency events and also absorb/inject active power to smooth wind power fluctuations. First part of offered research work, presented by this paper, estimates the rated power and energy capacities based on several constrains, including wind speeds and load characteristics. The second part discusses the impact of integrating suggested storage plant on frequency and power smoothing. Additionally, the criterion controlling energy storage and injection by storage plant is highlighted. Considered case study represents a defined sector from a genuine conventional grid merged with real wind speeds records at recommended locations to host wind farms. Results reveal the major technical aspects of required storage facility (e.g., number of pumps, reservoir height and volume as well as integrated generator(s) specifications). MATLAB and Simulink are the implemented simulation environments

Random operation of conventional distributed generators based on generation techniques

This paper presents a comparison between three different approaches to model the random operation of generation units in power networks for reliability studies. Monte Carlo simulation method is integrated with each of the proposed approaches to calculate the average power not supplied in a given system. The obtained results from each approach are compared to their corresponding values if obtained when seasonal operation is considered

Impact of distributed generation technology & operation techniques on distribution system reliability

The research work done in this paper is directed into two main routes. The first one is evaluating the impact of different conventional and renewable types of generation techniques on distribution systems’ reliability. The second route is developing an appropriate algorithm to model the operation schedules of distributed generators to obtain realistic and applicable reliability analysis for distribution systems integrated with distributed generators. Case studies are offered and the results obtained are presented and discussed