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.
The basic factors and general considerations in selecting the class and means of neutral grounding for synchronous generator systems connected to electrical utility systems are provided in this guide. It also provides the suggested methods and apparatus to be used to achieve the desired grounding. These guidelines apply to both large and small generators found in electrical utility systems. Definitions...
Operating characteristics of a large-scale wind farm consisting of series-connected outputs of thyristor rectifiers with 10 wind generators and current source thyristor inverter are simulated. The simulation model is constructed based on MATLAB/Simulink and PLECS. Instantaneous waveforms of various parts of the system are shown considering the wind speed distribution.
The significant mechanical inertia of the rotor in a synchronous generator is crucial for facilitating the cooperative grid forming capability of multiple such generators on the transmission and distribution network. This paper demonstrates that the DC link capacitance in a PV inverter is the analogous form of inertia for such a system, albeit having much smaller magnitude. Furthermore it proposes...
Predictive pole-slip protection is not implemented in commercially available protection relays. All pole-slip protection relays on the market will only trip a generator after it has pole-slipped one or more times. A predictive pole-slip protection algorithm was developed that can trip a generator before a pole-slip occurs. The Predictive Pole-Slip algorithm was tested on a Real Time Digital Simulator...
Power system protection and emergency control systems require continuous monitoring to prevent grid-wide frequency instability or system islanding. Amongst different methods, cellular computation networks (CCNs) are more suitable for providing dynamic frequency predictions. CCN is a scalable and distributed framework using the concept of cells and intercellular connections to represent a power system...
This paper presents a detail dynamic model of synchronous turbo-generator capable to take into account for rotor whirl. The model is based on a modified winding function approach that allows exact description of machine windings space distribution. Rotor whirl modeling is based on axial slicing of the machine and summing up on such way obtained winding inductances. On such manner, very complex 3D...
A fast step response of an excitation system is critical for a synchronous generator in order to maintain stability under disturbances in the interconnected power grid. This is the main reason that the static excitation system has been preferred for large synchronous generators. Some transmission system operators even have requirements that the excitation system should be static for synchronous generators...
The main objective is to study dynamic behavior of hydro generator at variable excitation. This paper presents analysis of the dynamic behavior of a hydroelectric power plant including hydraulic system, electrical installations, rotating inertia and control systems. First, the modeling of the electrical and hydraulic systems is described. The electrical system is constituted by a salient-pole synchronous...
When a greatly varying load is connected to a weak system, stability of the system becomes a problem. In these days, because the use of renewable energy is accelerating, not only the loads but also the distributed power sources can be critical factors in destabilizing the system. The virtual synchronous generator (VSG) control allows a static inverter to behave similar to a synchronous generator (SG)...
The paralleling of synchronous generators is one of the main and frequently implemented power system control tasks. The significant importance of automatic implementation of this task is determined by the need of fast and reliable restoration of an electrical power system (EPS) after emergencies. The value of this task has been dramatically increasing during the last years with the growth of the penetration...
In this paper a novel non linear feedback excitation controller has been proposed for improvement of transient stability of power systems. The design of the controller is based on the adaptive backstepping control principle. The controller takes into consideration system uncertainties. A significant merit of this non linear controller in comparison with existing non linear excitation control schemes...
In this paper the factors influencing the self-excitation process in the synchronous generator and a method of this process improvement are described. In the case of high stator windings inductance commutation process in the rectifier at the generator output interfere with successful self-excitation, which is confirmed by analytical calculations and practical experiment. Use of the excitation current...
The increasing complexity of electric grids including renewable sources causes significant impacts in terms of power quality. This implies that new generators are to be designed so that they can withstand larger and larger disturbances in the amplitude and frequency of the grid to which they are connected. This purpose can be attained by appropriate provisions in the generator electromagnetic design...
This work presents different methods of analyzing a large hydro generator with computational fluid dynamics, respectively two transient and two steady-state approaches. It also shows the evaluation of a new modelling method compared to the state-of-the-art pole sector models. The focus is on the end winding area and the influence of different ventilation schemes on heat transfer and fluid flow. The...
Several linear synchronous generators for the exploitation of sea wave energy have been proposed. Such machines do not require reactive power for the magnetization since they use permanent magnets for the excitation. The use of permanent magnets in a rough environment such as the marine environment may be a very weak point in the application of these kind of devices. In order to overcome this difficulty,...
The requirements in this standard are applied to 50 Hz and 60 Hz, two-pole and four pole, cylindrical-rotor synchronous generators driven by steam turbines and/or by combustion gas turbines. The drive may be direct or through a gearbox or other device that permits different speeds for the turbine and the generator. The generators covered by this standard are to have rated outputs of 10 MVA and above.
The free-piston linear generator (FPLG) is a high efficient energy converter. It is capable of converting chemical energy into electrical energy by using a combustion process. The FPLG can be used as an alternative energy converter for hybrid cars. The focus of this publication is to show the interesting advantages of the FPLG if used as decentral heat and power station. The first part of this publication...
This publication deals with the calculation and the measurement of the iron losses in a linear generator. The linear generator is intended for use in a hybrid power train design for a vehicle. The system surrounding the linear generator and some parameters have an influence on the linear generator and its iron losses. They will be explained to achieve a fundamental understanding of the requirements...
Airborne high-speed synchronous generators rated in the power range of megawatts have been discussed. These generators are nowadays necessary for new aerospace missions, such as directed energy weapon (DEW) and airborne radar (AR). Requirements, ferromagnetic materials for magnetic circuits, electromagnetic design and cooling techniques for high-speed multimegawatt generators have been discussed....
Compliancy to grid codes has been a driving force behind the development of variable-speed technologies for wind generation. This resulted in the doubly-fed induction generator (DFIG) to become a common technology. The operational benefits of the DFIG derive from the possibility of controlling the operating speed of the generator from the rotor windings. Even if constructively different, the Dual-Excited...
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.