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.
Under unbalanced grid conditions low order harmonic appears both at the DC output and AC inputs of the converter. Such harmonics lead to deterioration of performance of the system. This paper presents a novel feedback-based controller, which regulates directly converter voltages to eliminate of the 2nd ripple of DC link voltage to alleviate the stress of DC-link capacitor and to reduce the 3rd harmonic...
The Static Synchronous Compensator (STATCOM) is a shunt device using power electronics to control power flow and improve transient stability on power grids. A model of a 100Mvar GTO-based STATCOM on a 500kV transmission system is built and its dynamic response is simulated. The GTO-based STATCOM consists of a 48-pulse three-level inverter and its control system. The simulating result shows that the...
A control method for small domestic power plants using renewable energy is described in this paper. This method is not only capable of optimizing the working point of the plant but also implements active power factor correction and lowers the extant harmonic distortion in the line. The novel element in the proposed complex controller structure is the upper harmonic controller that minimizes the amplitudes...
Harmonic pollution in power system has become increasingly serious, and we have been aware of the harm of harmonic. In order to restrain harmonic and compensate reactive power, real-time and accurate harmonic detecting is very indispensable. This paper presents the generalized instantaneous reactive power theory and conducts simulation research on three generalized reactive current (harmonic and reactive...
Three-phase currents of STATCOM with conventional control strategy will be unbalanced and distorted when the STATCOM operates at the condition of non-ideal grid voltages. Special attention was paid to the influence of grid voltage quality on STATCOM current and a new control strategy was presented to counteract the influence in this paper. The unbalance and non-sine distortion of grid voltage causes...
In recent years, with the rapid development of the power electronic technology, various power electronic devices and nonlinear elements, especially of many kinds of rectifier and switcher, are applied widely in power system. Harmonics have produced serious adverse effects in the equipment of power generators and distribution system, and of their control and protection, as well as the users and the...
The traditional instantaneous reactive theory is one of strategies commonly used in reactive current detection. In reactive current detection of single-phase AC circuits, the traditional instantaneous reactive theory must build a virtual symmetrical three-phase circuit, so its algorithm is complicated and its real-time performance is bad. At the same time, the traditional strategy leads to comparatively...
This paper deals with a high-powered, low-loss and digital current disturbance generator. It can produce harmonic current, active current, inductive reactive current and capacitive reactive current, so it is able to simulate kinds of actual industrial situations. By using energy feedback technology, the generator feeds the power consumed by the current disturbance back to the grid. Thus, it can save...
When connecting the grid-connected power electronics systems to the utility system, one of the most important aspects to be considered is the synchronization with the grid system in phase and frequency. The synchronized speed and accuracy depend on the technology used in the phase-looked loop (PLL) system. Different kinds of PLL technologies have been published in recent years. A novel PLL structure...
This paper presents a structure of modified DC bus interconnected single-phase micro-grid, as well as a topology of power converter building block (PCBB) based on the DC bus to perform various functions in a distributed energy network. The main functions of the PCBB are: compensating the current harmonics produced by nonlinear load in the micro-grid, mitigating the voltage sag or swell of the electrical...
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.