Christophe Pasquier

State of art on load monitoring methods

This paper deals with a state of art about the most non-intrusive load monitoring (NILM) methods. These methods allow identifying consumption of the electrical loads. In the context of sustainable development, this is of growing interest and rapid evolution subject in recent years. The objective is to manage energy consumption by the determination of the operating schedule of individual appliances. These approaches have been developed to simplify the collection of energy consumption data. This technique for gathering appliance load information doesnpsilat require placing sensors on individual appliances, and hence an intrusion into the energy consumerpsilas property. This paper proposes an overview of the most popular methods and describes their advantages and disadvantages. It opens new perspectives which are under development in our laboratory. Our goal is to reduce the complexity of monitoring appliances and to find the most efficient method for identification.

Angular Modulation of Dual-Inverter Fed Open-End Motor for Electrical Vehicle Applications

In this paper, angular modulation index (AMI) implemented through a modified space vector modulation for the dual voltage source inverters (VSI) is proposed with the primarily aiming to reduce switching losses. The desired voltage across the load is synthesized by applying appropriate phase-angle displacement between space vector references. The proposed approach avoids the use of a dc/dc boost converter (which imposes loss and weight/price penalty to duplicate the dc-link voltage) and results to be particularly suitable for electrical/hybrid vehicle applications. Namely, the application of saving energy to keep driving has been identified as major concern. Hence, this work focuses on the strategy to enhance efficiency. The principles of the proposed controlling method and switching loss, which is reduced at least by 50%, are theoretically evaluated. This paper proposes a pioneering mathematical approach to correctly determine total harmonic distortion (THD) value of the voltage/current for the dual-VSI structure. Furthermore, simulation and experimental results prove that the proposed method insures benefits in terms of common-mode voltage, THD of the voltage, and switching loss reduction. The dual-VSI prototype supplying 1.5-kW induction motor is assembled in the laboratory to experimentally evaluate performance of the proposed method. Also, the simulation results carried out through MATLAB/Simulink environment are given to confirm performance of this easy-to-implement and high-efficient method.

Comparison of Matrix Pencil Extracted Features in Time Domain and in Frequency Domain for Radar Target Classification

Feature extraction is a challenging problem in radar target identification. In this paper, we propose a new approach of feature extraction by using Matrix Pencil Method in Frequency Domain (MPMFD). The proposed method takes into account not only the magnitude of the signal, but also its phase, so that all the physical characteristics of the target will be considered. With this method, the separation between the early time and the late time is not necessary. The proposed method is compared to Matrix Pencil Method in Time Domain (MPMTD). The methods are applied on UWB backscattered signal from three canonical targets (thin wire, sphere, and cylinder). MPMFD is applied on a complex field (real and imaginary parts of the signal). To the best of our knowledge, this comparison and the reconstruction of the complex electromagnetic field by MPMFD have not been done before. We show the effect of the two extraction methods on the accuracy of three different classifiers: Naive bayes (NB), K-Nearest Neighbor (K-NN), and Support Vector Machine (SVM). The results show that the accuracy of classification is better when using extracted features by MPMFD with SVM.

Reduction of power field radiation for PLC applications

In this article, we present our investigations on the radiation of the power-line communication (PLC) system. Power line communication or power line carrier is a technology for carrying data on a conductor usually dedicated to electric power transmission. At high frequency, the power lines, whose are dimensioned and adjusted for electrical energy transfer, not to carry high frequency (HF) data signal, act then as radiating antennas.

Adapted NSPWM for Single DC-Link Dual-Inverter Fed Open-End Motor With Negligible Low-Order Harmonics and Efficiency Enhancement

In this paper, the near-state pulsewidth modulation (NSPWM), adapted to be implemented in dual-voltage-source inverter (VSI) fed open-end motor, is proposed with the aim of mitigating low-order harmonics (which lead to current total harmonic distortion (THD) minimization). The following two proposed methods are studied in detail: 1) fixing phase angle displacement (PAD) between two VSIs to 120° while adjusting the modulation index (MI); and 2) fixing MI to the predetermined value (wherein low-order harmonics are highly mitigated) while adjusting PAD. Furthermore, the proposed approaches enhance efficiency by limiting the number of commutations within the switching interval. The paper also presents the mathematical approaches to accurately determine low-order harmonic components and switching losses for dual-VSI structure. The experimental setup, including dual-VSI and open-end induction motor, is assembled in the laboratory to evaluate performance of the proposed method. Finally, the simulation results, carried out in the MATLAB/Simulink environment, are found to be in close agreement with experimental data.

Voltage THD Reduction for Dual-Inverter Fed Open-End Load With Isolated DC Sources

In this paper, the near-state pulse width modulation (NSPWM), adapted to be used in dual-voltage source inverter (VSI) fed open-end load, is introduced primarily aiming to appreciably minimize the voltage total harmonic distortion (THD). Within the framework of the proposed method, the active time of pulses at the second inverter is relatively adjusted within switching interval (compared to the first VSI). The phase voltage harmonics are formulated for dual-inverter modulated by NSPWM; then, optimal adjustment is identified via a three-dimensional curve of phase voltage THD versus modulation index (MI) and phase angle displacement (PAD). Due to the limitation of MI in NSPWM, the desired output voltage is synthesized with modifying not only MI but also PAD between references of two VSIs. Furthermore, NSPWM inherently takes advantage of better efficiency compared to conventional space vector modulation due to switching only two phases within an interval (by clamping one phase to positive/negative dc-rail). The dual-VSI supplied by two isolated dc sources is assembled in the laboratory to experimentally evaluate the THD reduction feature of the proposed method; also, the simulation results obtained by means of a MATLAB/Simulink environment show close agreement with experimental data.

New strategy to balance neutral-point voltage in three-level VSI based on SVM regarding output current

This paper proposes new modulation strategy in order to balance neutral-point voltage in the three-level Voltage Source Inverter (VSI). In the proposed method, not only initial neutral-point voltages and wanted voltage vector but also resulted current is used to detect and apply appropriate space vectors. In this method, all space vectors can be categorized into two dynamic groups which are P-Type and N-Type vectors. For each dynamic category, containing vectors are selected based on resulted current vector. This method slightly injects high order harmonics which lead to enhance voltage THD, due to using small and medium space vectors. Respecting dynamic categorizing, the proposed method has strong capability to rapidly balance neutral-point voltage, with regardless ripple for all modulation index ranges and balanced/unbalanced loads. Simulation results verify the validity and capability of the modulation strategy, also the proposed method is easy to implement without adding any extra hardware and expenses.

Analysis of electrophysiological activities using Matrix Pencil Method

This paper presents a high resolution method for analyzing of electrophysiological activities using Matrix Pencil Method (MPM). This approach identifies measured signal from nerves to better understanding the functional organization of neuronal ensembles that form the peripheral nerves or the cerebral cortex. Matrix Pencil Method which is used to extract original signals and benefits from minimum exponential functions while having excellent reproducibility feature. MPM also can eliminate the noise part of the system and return pure original signal. In this paper, MPM is used to reconstruct recorded action potential from cockroach by using Matlab environment which shows less than 4% error.

Modified SVM to meet CMV and DC current ripple reduction

This paper introduces the Modified conventional SVM (MSVM) in order to improve CMV, switching losses, and THD feature of two-level Voltage Source Inverter (VSI). The proposed method divides nulltime, resulted from SVM, to these of two nearby active vectors, forming sector, to calculate new duty cycles. This modification also can be envisaged as transferring matrix, in which its elements are function of percentage of allocating null-time to active ones. Avoiding null-vectors not only result in reduction of CMV peak value but also lead to mitigating THD. Moreover, MSVM mitigates the number of commutations which are proportional to switching losses. In this work, theoretical approach to calculate switching losses, respecting load power factor is formulized. Mathematical approaches, simulation results, carried out through MATLAB/Simulink environment, and finally experimental results verify its validity in above-mentioned achievement. Proposed strategy is simply applied without adding any extra hardware and complex calculations.

Robust UWB radar target classification in white Gaussian noise based on Matrix Pencil Method in Frequency Domain and Mahalanobis Distance

In this paper, we propose a robust method for UWB automatic radar classification in white Gaussian noise and different aspect angles between the radar and the target. The method is based on the use of Matrix Pencil Method in Frequency Domain (MPMFD) for feature extraction and Mahalanobis Distance for classification. In order to test the accuracy of the proposed method, we have used complex target geometries modeled by perfectly conducting, straight, thin wires. Simulation results show that accurate results of radar target classification can be obtained by the proposed method. In addition, we prove that the proposed method has better ability to tolerate noise effects in radar target classification.