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.
For the control of electric motors, conventional inverters have utilized position and current sensors, but they undesirable in terms of cost and maintenance effort. For this reason, approaches without the sensors are developed by applying back electromotive force or signal injection-based method which also has some problems related to the the deterioration of control performance in low speed range...
Phase-locked loops (PLLs) are doubtless the most popular synchronization technique in the power converters. Almost all proposed PLL structures known in literature are inherently nonlinear and can be linearized as second order linear time invariant system. Nonlinear nature of PLLs degrades their performances, and question arises if there exist an enhanced PLL structure that would have superior performances...
This paper introduces a MATLAB simulation of 3 phase grid tied inverter which synchronizes with grid as per grid requirement. The aim of this simulation is an implementation of the designed filter to effectively reduce the ripple component injected into the grid to an acceptable value. The focus is on designing inverter which will synchronize with grid. The design and analysis of the grid synchronization...
In this paper, a fast-synchronization between grid and inverter based on virtual synchronous converter (VSCon) technique is achieved in single-phase inverter. Consequently, this technique is designed and simulated in Matlab/Simulink platform to perceive the significances during variation of grid load parameters. The VSCon is implemented for inverter output control that has a behavior of grid voltage...
Recently a variety of advanced PLL methods have been proposed for single phase grid connected applications. For such applications, the correct generation of reference signals is of the utmost importance. To ensure this, an accurate and fast estimation of the phase angle and the frequency of the utility voltage is essential. Among the methods proposed to achieve this, the Park PLL is the most commonly...
The actual synchrophase electric drive (SPED) control methods are built with a number of assumptions. Therefore the methods are full of flaws. The known time quasioptimal control method is based on the acceleration constancy assumption. It makes the phasing process inaccurate. Additional phasing process is needed. Phase plane method, control theory, electrical machines theory is used in the work....
In this paper we propose the structure and the functioning of a photovoltaic (PV) connected to the electric distribution and transmission network, equipped with the malfunction detection blocks. The studies that were carried focused on the injection of a power of 16 KW, produced by a PV panel field, on the electrical network of medium voltage (25 KV). In order to the reliability of the injection system...
Grid-voltage synchronization algorithm performs the main role during unbalanced and distorted grid fault condition to measure the positive- and negative-sequence values of grid voltage at the point of common coupling for grid-tied renewable energy sources. Power control during severe grid conditions mostly depends on these measured values. Three-phase synchronous reference frame phase-locked loop...
Due to the increasing popularity of renewable energies, a significant share of the power generation in future microgrids is expected to originate from converter-interfaced Distributed Energy Resources (DERs). Traditionally, idealized device models are used to conduct grid stability studies. For instance, a DER interfaced via a Voltage-Source Converter (VSC) would be modeled as an ideal current or...
This paper proposes a method to implement the modified square loop digitally on the FPGA to solve the problem, that the divide circuit in the traditional square loop is difficult to achieve. The modified square loop has a similar structure to the traditional square loop. The method of modified square loop is to multiply quadrature output together to replace the divide circuit. In this paper, a specific...
In this paper, control of a grid-tied converter as a voltage controlled converter is investigated for distribution level grids. Small signal model of the converter is presented and a control structure is designed to deliver desired active and reactive power. This controller is using power flow equations to control the converter as a synchronous machine and without the need for a dedicated synchronization...
In this paper, we review advanced synchronization techniques for the internet of things. Our study can be directly applied to the single-carrier IEEE 802.15.4 and IEEE 802.15.6 standards. In particular we display the advantages of using a Code-Aided approach and a Bayesian packet-oriented approach. The performances of several phase-locked loop techniques are compared to different Cramer Rao Bounds...
Many natural phenomena and engineering applications are based on synchronization between several periodic processes. A commonly known example is a phase-locked loop (PLL), that is, a feedback circuit providing synchronization between the endogenous oscillator and exogenous periodic signal in phase. Imprecise recovery of the signal's phase leads to decoding and demodulation errors, so the properly...
Rigorous nonlinear analysis of the physical model of Costas loop—a classic phase-locked loop (PLL) based circuit for carrier recovery, is a challenging task. Thus for its analysis, simplified mathematical models and numerical simulation are widely used. In this work a short survey on nonlinear models of the BPSK Costas loop, used for pre-design and post-design analysis, is presented. Their rigorous...
Phase-locked loops (PLL), Costas loops and other synchronizing circuits are featured by the presence of a nonlinear phase detector, described by a periodic nonlinearity. In general, nonlinearities can cause complex behavior of the system such as multi-stability and chaos. Even if the phase locking is guaranteed for any initial conditions, the transient behavior of the circuit can still be unsatisfactory...
We present in this work the study and the realization of a photovoltaic system connected to the network. This system was simulated in the Matlab/Simulink environment and a laboratory prototype was manufactured for various tests and measures. Results of MPPT control, PWM control of a DC/AC single-phase converter, signal filtering of harmonic of the inverter as well as synchronization with the network...
Many systems, arising in electrical and electronic engineering may be represented as an interconnection of LTI system and a periodic nonlinear block, as exemplified by phase-locked loops (PLL) and more general systems, based on controlled phase synchronization of several periodic processes (“phase synchronization” systems, or PSS). Typically such systems are featured by the gradient-like behavior,...
Phase locked loop (PLL) system implementation in information subsystem of active voltage rectifier (AVR) is determined by requirement of power factor correction and suppression of the higher harmonics in current reference signal in nonideal mains voltage conditions. The method of phase locked loop system synthesis based on state space formalism is proposed. Control algorithm is based on state feedback...
Microgrids represent one of the best candidates to redesign the architecture of the future distribution network. Such a model, in fact, promises to be able to properly manage a larger penetration of Distributed Energy Resources while improving the local production and utilization of energy. On the other hand, the control of a Microgrid is quite challenging, since the system has to be particularly...
Networks timing information's 24×7 wander monitoring solution, actual both for Telecom synchronization networks and for IEEE1588 based networks, including optimally controlled PLL desing is described in this article. It also mentions a cost effective SDH or SyncE signals' probe unit design, expanded MTIE/TDEV metrics, and some monitoring experience with non- trivial results concerning GPS related...
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.