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Power system restoration takes place where power systems experience a blackout and might be splitted into several islands with limited number of black start units. The main challenge of the restoration process is to keep both frequency and voltage within allowable limits while restoring the network through energizing lines and transformers as well as load pickup. The load pickup scheme is determined...
A Power Hardware in the Loop (FHIL) platform implementation for performing real time simulations of electric systems is proposed. The test bench consists of a FSS'®E real time power flow calculation in combination with a controlled grid emulator. Experimental results are presented to demonstrate the performance of the platform.
This paper presents the possibility of using a point-to-point voltage source converter — high voltage direct current (VSC-HVDC) transmission system connecting offshore wind power plant (WPP) to the onshore grid as black start unit to initiate the restoration process for an interconnected electrical system after a large area system blackout. The onshore converter station (CS) provides voltage in order...
The grid-tied low voltage photovoltaics are expanded day by day. Aiming for a high penetration level, the Fault Ride Through Capability (FRTC) standard should be extended to these units as well. In this paper, the behavior of Single Phase Grid Connected PV Systems under faulty conditions is investigated. For this purpose, a SPWM controlled full bridge voltage source inverter is used. The proposed...
This paper presents a self-tuning adaptive control structure designed through the minimization of a criteria function. It is described the computation methodology of the control law, being particularized for the case of a dual winding induction generator's excitation control. The parameter's estimator, integrated into the control system, is based on the online least mean square error algorithm. In...
This paper covers the modelling of the standard IEEE 14 bus system using the MATLAB package. The basic system is tested under large and small disturbances to study the dynamic behaviour of the system and the stability margins associated with the different configurations of the system. As a suggested solution to increase stability margins of the system, Sen transformer is added, modelled and tested...
Most traction substations are equipped with 12-pulse passive rectifiers. Therefore, Total Harmonic Distortion (THD) of the input current is high, and feedback of braking power into the grid is not possible. Also, the overhead line voltage fluctuates seriously with varying loads. Imtech has developed a bidirectional supply for traction substations based on IGBT technology. The power electronics consist...
The paper presents the topology and functioning of the model-based laboratory system to study the power electronic converters structure and execution and to evaluate their different duty modes of operation. Detailed description of the models of ac/dc, dc/ac, ac/ac and dc/dc virtual power converters and their auxiliary circuits are given. Learning possibilities and restrictions of the described software...
Bayesian networks (BNs) are a powerful means for modelling dependencies and predicting impacts of architecture design changes on system quality. The extremely demanding parametrization of BNs is however the main obstacle for their practical application, in spite of the extensive tool support. We have promising experiences from using a tree-structured notation, that we call dependency views (DVs),...
This paper presents a review of some techniques for islanding detection, especially by using inverter based DG applications and it also focuses on several islanding detection methods for a single-phase current-control voltage inverter working with a PV system connected into the grid. It is deliberated a single-phase inverter with maximum power of 5 kW. Islanding detection methods are investigated,...
The Modular Multilevel Converter (M2C) is an emerging and highly attractive multilevel converter topology for medium and high voltage applications. In this paper, a new pulse width modulation (PWM) scheme will be derived. For this pulse width modulation scheme, characteristic simulated waveforms are described and analyzed.
According to high power factor and accurate outputs DC voltage which are requirements of three-phase rectifier control as known, the research establishment of one outer voltage loop and two inner current loops as double-loop control system. The outer voltage loop could resist disturbance to achieve accurate output; the inner current loop based on space vector control to achieve high power factor....
Fuel cell with supercapacitors is a multi-physical system which, in association with converters, becomes hybrid. To model this complex system, different proposals have been made in literature. In this paper, Component Hybrid Dynamic Nets (CHDN) are used to model this system. CHDNs are a graphic model for hybrid systems, which allow each component of the hybrid system to be represented; moreover a...
The purpose of this paper is to analyze the stability of closed loop switching power amplifiers using an accurate model of a loudspeaker installed in a commonly used bass reflex enclosure instead of the purely resistive model that can be used with a Zobel network. The model takes into account the electrical-mechanical-acoustical parameters of the transducer as well as the voice-coil loudspeaker's...
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