The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
With increasing wind power in power systems, impact of wind generators on subsynchronous resonance (SSR) is of interest. Previous research has shown the impact of wind generation on SSR. In this paper, a control strategy is developed utilizing the power converters' control capability in a doubly fed induction generator (DFIG)-based wind turbine system. The control is realized through modulating the...
Current grid codes require the fault ride-through capability of modern wind turbines. During grid faults the reactive current control of the wind turbines should be used to support the grid voltage. With modern protection devices the fault durations are normally in a range of some hundred milliseconds or less. However this time window may be decisive for the stability of the conventional generators...
Using bulk energy storage systems such as pumped-hydro electric storage (PHES) and compressed-air energy storage (CAES) with wind power plants offers advantages. They are well-proven technologies and more economical compared to batteries. Being synchronous machines, apart from the ability to regulate wind farm real power output, they can also be used to provide reactive power to support wind farms,...
This paper proposes a new pricing mechanism and dispatch model for reactive power service from distributed generation (DG) resources, including wind turbines and solar photovoltaic plants, connected to a low voltage distribution system. Novel cost functions of reactive power service are proposed for DG resources as well as alternative VAR suppliers such as STATCOM and capacitor banks, taking into...
Notwithstanding the positive environmental impact, the increasing penetration of Distributed Generation (DG) units connected to the distribution network raises new topics concerning the expected response of these during outages. Grid disturbances especially at the transmission level can cause the unwanted disconnection of large amounts of DG, leading to undesired power imbalances causing line overloadings...
As the issues on market deregulation and renewable energy utilization are gaining significance, distributed generators are planned and installed in distribution systems to supply consumers directly. The distribution system is, therefore facing new challenges on its dynamic behavior with the addition of new dynamic devices. This paper investigates the small signal stability of renewable energy based...
This paper deals with a voltage and frequency controller (VFC) of a stand-alone wind energy conversion system using an isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The reference generator currents are estimated using the power balance theory to control the voltage and frequency of IAG system. Two-leg reduced switch integrated voltage source converter (VSC) with a battery...
A nonlinear adaptive neuro-fuzzy inference system (ANFIS) based controller is proposed for power electronic systems (PES) of grid connected unified doubly-fed induction generators (DFIG). The unified DFIG utilizes an additional series grid-side converter (SGSC) connected in series with the stator winding of the DFIG to inject voltage into the grid for compensation purposes. The SGSC is useful in tolerating...
Wind energy is the fastest growing source of renewable energy in the power industry and it will continue to grow worldwide as many countries are developing plans for its future development. For power system operators, this increasing contribution of wind energy to the grid poses new challenges that need to be addressed in order to ensure the reliability and security of the electric power grid. One...
This paper studies the short-term grid voltage stability of double cage induction generators in fixed speed wind turbines. The performed analysis shows that for voltage stability studies of fixed speed wind turbines with induction generators (either single or double cage), the mechanical rotor turbine model is preferable as a detailed aerodynamic model. Simulations of the suggested modeling approaches...
The active power produced by wind generators is subject to fluctuations due to the stochastic nature of wind. Depending upon the size of the wind farm and the network to which it is connected, active power variations may result in frequency deviations. This can trigger frequency protection devices and lead to undesirable unit trippings. This paper proposes the addition of a small supercapacitor at...
This paper presents a performance analysis of wind-powered self-excited induction generator (SEIG) and a vector-controlled PWM converter. Three-phase voltage-source converters are the building blocks of a large number of power electronic systems. The origin of difficulties in the control of the above converters is in their nonlinear nature. The PWM current control technique is used to derive the switching...
The control algorithms proposed in the literature so far for the Double Output Induction Machine Based Variable Speed Constant Frequency (VSCF) stand alone generators suffer from the disadvantage of loss of `field orientation' during sudden load disturbance at the machine terminal. As a result, undesirable transients are observed in the load voltage during such transients. This paper presents a new...
Wind generation is evolving from single wind turbines to wind power plants with an installed capacity of tens of megawatts. Therefore, wind turbines are also coupled to the transmission grid instead of the distribution grid. Problems arise during grid faults as the behaviour of wind turbines equipped with doubly-fed induction generators differs fundamentally from traditional synchronous generators...
The probabilistic small signal stability analysis (PSSSA) considering uncertainty and randomness of wind generation is conducted in this paper. Firstly, the small signal model for wind farm with Doubly-fed Induction Generator (DFIG) type is presented. The stator flux-oriented vector control based method is utilized to implement stator active and reactive powers control in modelling rotor-side converter...
This paper describes the use of generic wind turbine models to study the comparative inertial response of wind turbine technologies, that is, their response to a frequency event on the grid such as loss of generation. The dynamic models are manufacturer-independent and portable to any dynamic modeling software. Four dominant types of wind turbine technology are modeled; the basic fixed-speed model...
This paper discusses about the ride-through capability of a large induction-generator based wind park with different reactive power support solutions. Three different solutions have been compared and it has been shown that conventional switching of capacitors is able to help the wind park meet the Nordel gird code requirements on low voltage ride-through. The requirements on rating are shown to be...
Oscillation damping via variable speed wind generators have been addressed in literature. Among the techniques, active power modulation has been studied. However, active power is closely related with electromagnetic torque. Modulating active power can introduce oscillations in the torque. This is undesired. The objective of this paper is to study an alternative technique - reactive power modulation...
With increasing penetration of wind power, there is rising need to manage its intermittency. This paper explores the control and operational aspects of integrating a short and long-term storage mix, consisting of a fuel-cell, an elcetrolyzer and an ultracapacitor, into the double-fed induction generator based wind-power system, making it dispatchable. The fuel-cell/electrolyzer is employed to provide...
Summary form only given. The paper applies the method of eigenstructure assignment for the design of a controller for a wind generation scenario in Northern Scotland based on doubly-fed induction generators (DFIGs). The designed controller serves the combined purpose of a conventional power system stabilizer (PSS) and an active damping controller and provides a contribution to both network and shaft...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.