The use of Multilevel Inverters (MIs) in PMSM drives is a possible solution for motor harmonic power losses reduction. In this regard, their experimental determination is a challenging task. This paper addresses an experimental analysis of harmonic losses introduced in an IPMSM drive fed by a Cascaded H-Bridges Multilevel Inverter (CHBMI) controlled with different MultiCarrier PWM strategies (MC-PWM). For this purpose, a frequency domain power analysis approach has been adopted to separate the active power value generated at the fundamental harmonic frequency and the power losses at the higher harmonics. In this analysis, several working conditions, defined in the frequency-torque plane, have been considered and the detected IPMSM total power losses, fundamental power losses and harmonic power losses have been discussed.
The international standard IEC 61800-9-2 introduces energy efficiency classification for frequency converters or complete drive module (CDM) and provides instrumentation minimum requirements for accurate measurement of CDM input and output power valid for conventional pulse-width-modulated (PWM) voltage source inverter (VSI).This paper highlights the necessary improvements to update the standard with more detailed prescriptions according to the converter topologies and the modulation techniques adopted.In this framework, this paper address the power analysis in the frequency domain of a cascaded H-bridges-multilevel inverter (CHBMI) in an interior permanent magnet synchronous motor (IPMSM) drive for the identification of the minimum measurement bandwidth.The power spectrums are analyzed for different modulation strategies, different switching frequency values and IPMSM working conditions.
In order to guarantee a correct classification in the standardized energy efficiency classes, the current standards concerning the power drive systems prescribe that their power losses must be evaluated with great accuracy. This circumstance involves the usage of expensive measurement systems, since accurate instrumentation, skilled personnel and controlled environments are required. During the design stage of a power drive system, however, the measurement of the absolute value of its power losses is not always needed. Often, in fact, it is enough to assess the power losses variations caused by a modification of either hardware or software sections of the power drive system. In these cases, it is possible to evaluate the losses by means of differential measurements. The aim of the paper is the uncertainty characterization of this kind of measurements. The analysis is carried out by experimentally comparing the performances of three measurement systems, each one characterized by different accuracy and cost. The results show that even the systems not adequate to measure the absolute values of power losses can be used to accurately assess their variations.
In the last decade, the issue of air pollution or the reduction of CO2 emissions has become of extreme interest both for civil society and then for the industrial and scientific research world. For this reason, the scientific research on automotive is called to answer with increasingly innovative solutions. One of the principal subjects are the storage and the utilization of the electric energy for electrical and hybrid vehicles. Nowadays, supercapacitors are getting more and more attention because of their characteristics that allow them to be a bridge between electrolytic capacitors and batteries in several application such as bust-mode energy delivery, regenerative breaks and so on. The aim of this work is the modelling, simulation and characterization of a supercapacitor for the seen automotive applications.
Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are the most appropriate and feasible solutions. In this article, three different battery modeling approaches are considered, and their parameters’ identification are described. Two of the chosen models require no laboratory tests for parametrization, and most of the information are derived from the manufacturer’s datasheet, while the last battery model requires some laboratory assessments. The models are then validated at steady state, comparing the simulation results with the datasheet discharge curves, and in transient operation, comparing the simulation results with experimental results. The three modeling and parametrization approaches are systematically applied to the LG 18650HG2 lithium-ion cell, and results are presented, compared and discussed.
The research of innovative solutions to improve the efficiency of electric drives is of considerable interest to challenges related to energy savings and sustainable development. In order to successfully validate the adoption of new and innovative software or hardware solutions in the field of electric drives, accurate measurement procedures for either efficiency or power losses are needed. Moreover, high accuracy and expensive measurement equipment are required to satisfy international standard prescriptions. In this scenario, this paper describes an accurate measurement procedure, which is independent of the accuracy of the adopted instrumentation, for the power losses variations involved in electrical drives, namely ΔΔP, useful to detect the efficiency enhancement (or power losses reduction) due to the real-time modification of the related control algorithm. The goal is to define a valuable measurement procedure capable of comparing the impact of different control algorithms on electric drive performance. This procedure is carried out by experimentally verifying the action of different control algorithms by the use of a Field Oriented Control (FOC) with different values of the direct-axis current component (i.e., Id = 0 A and Id = −1 A) applied for fixed working conditions in terms of speed and load torque. Two different measurement systems of power losses, each one characterized by different accuracy and cost, are taken into account for the validation of the proposed method. An investigation is, then, carried out, based on the comparison between the measurements acquired by both instrumentations, for different working conditions in terms of load and speed, highlighting that the uncertainty generated by systematic errors does not affect the ΔΔP measurements. The results reported in this work demonstrate how the ΔΔP parameter can be used as a valuable index for the characterization of the power drive system, which can also be evaluated even with low-accuracy instrumentation.
Selective harmonics elimination or mitigation strategies are used in all applications where it is necessary to rise the efficiency and reliability of the overall system. This paper presents a simple approach to reduce the low order harmonics amplitude of an asymmetrical staircase voltage waveform for a five-level, three-phase Cascaded H-Bridge Inverter without solving non-linear equations. Through this simple approach, polynomial equations to evaluate the control angels in real-time operations have been found. The effectiveness of the harmonic mitigation method has been tested through the simulation analysis in MatLab/PLECS environment.
– This paper presents a general procedure for the accurate measurement of power losses variations in electrical drives. More specifically, the paper addresses the issue related to the efficiency comparison of electrical drive controlled with different control algorithms. This procedure is applied to a permanent magnet synchronous motor drive, assessing its power losses by means of two different measurement systems, each one characterized by different accuracy and cost. The comparison between these two systems is carried out for different working conditions in terms of load, speed and magnetization in order to demonstrate that the power losses variations can be accurately measured even with not expensive instrumentation.
This paper deals with electrical drives employing low-saliency ratio interior permanent magnet synchronous motors. In particular, in order to help the designers choosing the best control algorithm, the performances of the Maximum Torque Per Ampere Control and the Field Orientation Control are here both theoretically and experimentally assessed and compared, by using, as performance indicators, the torque-current ratio and the power losses. The tests are carried out on a low-power motor for various speeds and loads by implementing the two control strategies in a dSPACE ® rapid prototyping system. The results show that the Maximum Torque Per Ampere algorithm has some appreciable advantage mainly for high load conditions of operation.
In this paper, an experimental investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs) is described, analyzed and discussed. This investigation was carried out on a small-power IPMSM with low saliency ratio. More in detail, after a previous simulation study, the control techniques have been experimentally implemented and validated through means of a dSPACE ® rapid prototyping system. The performances of the two algorithms have been evaluated and compared, obtaining interesting results.
The wireless power transmission (WPT) is increasingly representing a promising technology and an innovative solution, especially for the electric vehicles (EVs) battery charging. The inductive power transfer (IPT) is the standard technology of wireless charging: the energy transfer occurs between two magnetically coupled coils. The IPT-based battery charging is especially convenient for E-bikes and the physiological effects related to the generated magnetic fields should be estimated. In this context, this work presents a 200W prototype of wireless battery charger for E-bikes. In addition, the measurements regarding the surrounding magnetic field are given in detail in order to evaluate the actual physiological compatibility of the system.
The paper provides the results of a detailed experimental study on the variations of the characteristics of an interior permanent magnet synchronous motor, when load, speed and/or magnetization conditions vary. In particular, the characterization is carried out by assessing, for several working conditions, the motor parameters that influence its efficiency. From the knowledge of the variability of these parameters, it is possible to develop a dynamic model of the motor, which accurately describes its behaviour and allows estimating the power losses for whatever speed and load. In order to validate the model, the values of the power losses obtained by using the model are compared with the values measured with experimental tests. The study shows that it is possible to maximize the motor efficiency just acting on the direct axis current component and, therefore, it can be considered a first step towards the definition of a loss model algorithm for a control drive system able to minimize in real-time the power losses of the motor.
This paper presents an experimental study on the impact of the parameter variations over the performances of a LMA (Loss Model Algorithm) designed for an IPMSM (Interior Permanent Magnet Synchronous Machine). In a previous work, the characterization was carried out by assessing, for several working conditions, the motor parameters that influence the motor efficiency. The proposed enhanced loss model algorithm is implemented in a rapid prototyping system and its performances, in term of efficiency, are compared with other control systems, obtaining promising results.
This paper shows the technical and economical evaluation of the application of a reconfiguration system for photovoltaic (PV) plants, considering the incentives system in some European Union countries. The reconfiguration system is an alternative to the distributed maximum power point tracking technique which used to increase the power production in the PV plants under the mismatch phenomenon. The reconfiguration techniques employ a microprocessor-based or field-programmable gate array-based system that modifies the layout of the PV plant through the change of the connections among modules. After having presented the main features working of the PV reconfiguration system allowing the improvement of the efficiency of the same plant and the relevant installation, the main strength and weakness points of the investment are evidenced in relation to different incentives policies in some country of UE.
This paper presents an investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs). In particular, this study was carried out on a small-power IPMSM with low salience ratio. Both control algorithms have been implemented in the Matlab/Simulink environment, obtaining promising results.
This paper presents the performance comparison of PV windows with the purpose of tracing the behavior of next-generation systems, which could favor architectonical integration. More in detail, a dye sensitized solar cell (DSSC) and blue and grey thin film silicon panels have been analyzed. The systems can be placed behind a window or behind a wall of glass blocks. The three generation systems are then compared in terms of both efficiency and Fill Factor.
The paper proposes a new electronic load setup for a fast, low-cost and standard-compliant characterization of a photovoltaic module. The approach is based on the use of a DC–DC converter, exploiting its ability to emulate a resistor. In particular, a Buck-Boost converter topology is employed. The model is implemented in the Simulink/SimPower System environment. A commercial PV Conergy E215P photovoltaic module is used in order to evaluate the performances of the proposed electronic load and to validate the proposed approach.
This paper presents the experimental characterization of a wind turbine prototype used for micro wind farms. The proposed prototype, whose advantages can be summarized in versatility of application, low noise and compactness, can generate 1 kW of rated power for a wind speed equal to 4 m/s. The tests here reported and carried out by means of an experimental test bench confirm that the prototype is well designed and adequate for the purpose of its application.