Three-Phase Electrical Systems

2020 ◽  
pp. 85-118
Author(s):  
Rubén Molina Llorente
Keyword(s):  
Electrical Systems ◽  
Three Phase

SIHG Testing and Analysis

2010 ◽  
Author(s):  
Gregory Bredariol ◽  
Aaron Garnier ◽  
Kevin Stevens ◽  
Andrew Foley
Keyword(s):  
Power Output ◽  
Turbine Blades ◽  
Coast Guard ◽  
Maximum Efficiency ◽  
Actual Performance ◽  
Electrical Systems ◽  
Hydroelectric Generator ◽  
Green Power ◽  
Three Phase ◽  
Thames River

This paper describes the Sailboat Integrated Hydroelectric Generator (SIHG). This turbine is intended to be fixed to the transom of a 30–40 foot sailing vessel to produce green power for the vessel’s electrical systems. The design goal for the SIHG was the generation of a minimum of 225 watts at 6 knots and an ideal output of 400 watts at 6 knots. Power is generated by the SIHG when water moving over five turbine blades creates rotational motion, which is transferred through a gear box to a three-phase electrical generator. The three-phase electrical output is then rectified and used to recharge the boat’s battery. Presently, most sailboats of this size run their engines in order to recharge their batteries. The SIHG produces no emissions and has no operating costs. Extensive testing in the Thames River at the U.S. Coast Guard Academy in New London Connecticut produced data that was then used to determine the power output and efficiency of the SIHG at various speeds through the water. The turbine was fixed to the transom of a dinghy which was then towed behind a rigid hulled inflatable vessel to simulate a sailboat under wind power. Novel data collection methods and instrumentation were then used to gather power and drag data for the turbine at various speeds. Power output plots and efficiency curves were calculated from this data and are represented in this paper. Actual performance shows that the SIHG is capable of producing 275 watts at 6 knots and 400 watts at 8 knots. The maximum efficiency of the SIHG is calculated to be 37% and occurs when traveling through the water at a speed of 5 knots. Due to the substantial power generation at relatively low speeds, tidal applications are discussed.

The Broken Symmetry of Output Currents in a Matrix Converter and Its Recovery Control

2020 ◽  
pp. 2150072
Author(s):  
Manuel Sánchez ◽  
Takafumi Okuda ◽  
Takashi Hikihara
Keyword(s):  
Matrix Converter ◽  
Delayed Feedback Control ◽  
Broken Symmetries ◽  
Electrical Systems ◽  
Input And Output ◽  
Three Phase ◽  
The Matrix ◽  
Dc Component ◽  
Nonlinear Behaviors ◽  
Time Delayed Feedback

Symmetry is not only used to simplify the analysis of three-phase electrical systems, but it is also used to define its voltages, currents and loads. When the loads are symmetrical, the currents of a three-phase AC system are expected to be symmetrical as well. Given the proper conditions, in converters such as the matrix converter (MC), the output voltages and currents are expected to be sinusoidal with periodic symmetry. However, in some cases this symmetry is broken so that, there appears nonlinear behaviors such as quasiperiodicity and so on. Based on simulations and experiments, this paper focuses on an analysis of a quasiperiodic behavior and the presence of a DC component in the output currents of a Venturini modulated MC. The presence of such behaviors in the output currents indicates that the symmetry in a period is broken. The broken symmetries appear when the input and output frequencies are mismatched. In addition, this paper shows the possibility to recover the symmetry of the output currents of the MC. The method for symmetry recovery is based on a time-delayed feedback control. The simulation and experimental results indicate the possibility of attenuating the quasiperiodic behavior and DC component.

scholarly journals An Alternate Representation of the Vector of Apparent Power and Unbalanced Power in Three-Phase Electrical Systems

2020 ◽  
Vol 10 (11) ◽  
pp. 3756
Author(s):  
Pedro A. Blasco ◽  
Rafael Montoya-Mira ◽  
José M. Diez ◽  
Rafael Montoya
Keyword(s):  
Nonlinear Systems ◽  
Distribution Systems ◽  
Low Voltage ◽  
Practical Case ◽  
Voltage Distribution ◽  
Efficient System ◽  
Electrical Systems ◽  
Three Phase ◽  
Unbalanced Loads ◽  
Wire System

Low-voltage distribution systems are typically unbalanced. These inefficiencies cause unbalanced powers that can significantly increase the apparent power of the system. Analysing and measuring these inefficient powers appropriately allows us to compensate for them and obtain a more efficient system. Correcting the imbalance at some nodes can worsen the rest of the system; therefore, it is essential that all nodes are analysed such that action can be taken when necessary. In most studies, the unbalanced power is measured from the modulus. Other more recent studies have proposed phasor expressions of unbalanced powers; however, in both cases, these are not enough to address the compensation of unbalanced powers in systems with unbalanced voltages. In this work, a different representation of the vector expressions for analysis of the unbalanced powers and the apparent powers of the three-phase linear systems is proposed. Additionally, these vector expressions are extended to nonlinear systems to quantify the harmonic apparent powers. These expressions have been formulated from the power of Buchholz and are valid for systems with unbalanced voltages and currents. To help understand the use of the proposed formulation, a practical case of a three-phase four-wire system with unbalanced loads and voltages is demonstrated.

scholarly journals Formulation of the Phasors of Apparent Harmonic Power: Application to Non-Sinusoidal Three-Phase Power Systems

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1888
Author(s):  
Pedro A. Blasco ◽  
Rafael Montoya-Mira ◽  
José M. Diez ◽  
Rafael Montoya ◽  
Miguel J. Reig
Keyword(s):  
Power Systems ◽  
Harmonic Distortion ◽  
Electrical Systems ◽  
Three Phase ◽  
Non Linear ◽  
Orthogonal Parameters ◽  
Power Application ◽  
The Time Domain ◽  
Non Linear System ◽  
Harmonic Power

In this work, the expression of the phasor of apparent power of harmonic distortion is formulated in the time domain. Applying this phasor along with the phasor of apparent unbalance power allows us to obtain a new set of phasors that include all of the inefficient power components appearing in the transfer of energy in non-linear and unbalanced systems. In this manner, a new model of inefficient power in electrical systems is developed. For each voltage harmonic of order ‘m’ and current harmonic of order ‘n’, a phasor of harmonic apparent power is obtained. Accuracy in the determination of the total apparent power of a system depends on the number of harmonics considered. Each phasor of apparent harmonic power is formed from six mutually orthogonal parameters or components that are calculated from the harmonic voltages at the nodes of the network and the circulating harmonic currents. To demonstrate the validity of the proposed formulation, a four-wire non-linear system formed by two nodes is assessed.

Test of the stability of a three-phase contact line with negative line tension

1999 ◽  
Vol 96 (9) ◽  
pp. 1335-1339 ◽  
Author(s):  
ALAN E. VAN GIESSEN, DIRK JAN BUKMAN, B.
Keyword(s):  
Contact Line ◽  
Line Tension ◽  
Phase Contact ◽  
Three Phase ◽  
The Stability
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