Martin, G.; Sala-Pérez, P.; Ferrater, M.; López-Mestre, J.; Bergas, J.; Montesinos-Miracle, D. European transactions on electrical power p. 1-12 DOI: 10.1002/etep.1640 Data de publicació: 2012 Article en revista
Phase-locked loop schemes are widely used in induction heating applications for controlling the converters.
Most authors use total or partial analog solutions to implement the control schemes, which are less sturdy
and flexible to changes than digital schemes. In this paper, an all-digital DSP-based PLL is presented. It
has fewer variations due to the tolerances of the analog components and provides great flexibility in a wide
range of conditions just by reprogramming. Moreover, it allows changing dynamically some of the parameters
during the process and opens up the possibility of more complex control algorithms. The all-digital
PLL has been simulated and experimentally tested, demonstrating the feasibility and reliability of this type of
control in a real industrial equipment
To minimize the adverse impacts of power quality disturbances on the electric power supply as well as on the customer equipment, there is clearly a need for detection and classification of such problems. In this paper, a fast detection algorithm for power quality disturbances is presented. The proposed method is a hybrid of two
algorithms, abc–0dq transformation and 908 phase shift algorithms. The proposed algorithm is fast and reliable in detecting most voltage disturbances in power systems such as voltage sags, voltage swells,
interrupts, flicker, harmonics, etc. In the proposed approach, the three-phase utility voltages are sensed separately by each of the algorithms. These algorithms are combined to explore their individual strengths for a better performance. When a disturbance occurs, both algorithms work together to recognize this distortion and send trip signals to static transfer switches. This control method can be used for critical loads protection in case of utility voltage distortion. Simulation and analysis results obtained in this study illustrate high performance of the strategy in different single-phase and three-phase voltage distortions.
Pouresmaeil, E.; Montesinos-Miracle, D.; Gomis-Bellmunt, O.; Sudria, A. European transactions on electrical power Vol. 21, num. 7, p. 2007-2022 DOI: 10.1002/etep.536 Data de publicació: 2010-12-07 Article en revista
In this paper, the synthesis and performance of a shunt active power filter (SAPF) based on instantaneous active, and reactive current components (i-d i-q) technique is presented. The proposed active filter acts as a current source, which is connected in parallel with a nonlinear load and controlled to generate the required
compensation currents. The proposed control technique for SAPF aims to compensate the harmonic current contents of nonlinear loads by connection of distributed generation (DG) resources based on renewable energy sources to distribution network. This modeling is derived from the 123(abc)to αβ and αβ to dq
transformation of the ac system variables. The injected currents by the SAPF to polluted grid are controlled in synchronous orthogonal dq reference frame by using of decoupled current control technique. By use of phase locked loop (PLL) in control circuit of proposed technique, the angle of positive sequence has been detected, in order to synchronize the SAPF injected currents to distribution network. The proposed control strategy has this ability to eliminate wide range of harmonic frequency draws from utility grid, and provide the compensation currents by DG resources. By this control method, replacement of distributed power generation systems as an active power filter can be possible. Three-phase three-level neutral-point-clamped (NPC) voltage source inverter (VSI) is proposed for the interfacing between renewable energy resources and
polluted distribution network. The simulation results demonstrate high performances of proposed SAPF technique.
Torrent, M.; Andrada, Pere; Blanque, B.; Martinez, E.; Perat, J.; Sanchez, J. European transactions on electrical power Vol. 21, num. 1, p. 757-771 DOI: 10.1002/etep.475 Data de publicació: 2010-07-12 Article en revista
The prediction of switched reluctance motor (SRM) performance requires knowledge of core losses.
However, the calculation of iron losses in SRM is especially complex first because the flux waveforms are
nonsinusoidal and different parts of the magnetic circuit have different waveforms and second because they
are conditioned by the type of control used. This study proposes an analytical method for calculating core
losses that comprises simulation of the SRM using finite element analysis to determine the magnetization
curves, and SRM modeling, which enables transient simulations with the associated electronic power
converter run under different control strategies. The flux density waveforms in the different parts of the SRM
are derived from the flux density waveform of the stator pole that is obtained from the transient simulation.
The specific core losses (in W/kg) are separated into three parts (hysteresis losses, classical eddy current
losses and excess losses) and calculated using the waveforms and time derivatives of the local flux density.
The core losses for each part of the SRM’s magnetic circuit can be estimated using the calculated values for
specific hysteresis losses, specific classical eddy current losses and specific excess losses for each zone.
Adding these individual losses yields the total core losses. The method was applied to three-phase 6/4 SRM,
and the calculated results were compared with experimentally obtained measurements.
Cusido, J.; Romeral, L.; Garcia, A.; Ortega, J.A.; Riba, J. European transactions on electrical power Vol. 21, num. 1, p. 475-488 DOI: 10.1002/etep.455 Data de publicació: 2010-06-28 Article en revista
A new technique for induction motor fault detection and diagnosis is presented. This technique, which has
been experimentally verified in stationary and non-stationary motor conditions, is based on the convolution
of wavelet-based functions with motor stator currents. These functions are tuned to specific fault frequencies
taking into account motor speed and load torque, thus considering variable operation conditions of the motor.
Based on this technique an automatic system for fault diagnosis is also presented, which is suited for easy
Valsera-Naranjo, E.; Sumper, A.; Gomis-Bellmunt, O.; Junyent-Ferré, A.; Martínez, M. European transactions on electrical power Vol. 21, num. 7, p. 1-23 DOI: 10.1002/etep.535 Data de publicació: 2010 Article en revista