Speed and Position Estimation for Sensorless Control of PMSM: A Critical Review

Author(s):  
Shweta Singh ◽  
Amar N. Tiwari ◽  
Sri N. Singh

The Vector control scheme widely used for control purposes of PMSM drives requires rotor position information. Generally, sensors are used for this purpose, which increases the cost, size, and complexity of the system and also reduces the efficiency of drives. Therefore, it has become essential to avoid the use of these sensors and go for sensorless drives. In this paper, different types of speed and position estimation techniques are reviewed for sensorless control with their recent developments and their inherent advantages and disadvantages.

2021 ◽  
Vol 12 (1) ◽  
pp. 9
Author(s):  
Yong Li ◽  
Hao Wu ◽  
Xing Xu ◽  
Xiaodong Sun ◽  
Jindong Zhao

Permanent magnet traction motor has the advantages of high efficiency, high power density, high torque density and quick dynamic response, which has been widely used in the traction field of electric vehicle. The high-performance control of permanent magnet traction motor depends on accurate rotor position information, which is usually obtained by using mechanical position sensors such as hall sensor, encoder and rotary transformer. However, the traditional mechanical sensor has the disadvantages of high cost, large volume and poor anti-interference ability, which limits the application of permanent magnet motor. The sensorless control technology is an effective way to solve the above-mentioned problem. Firstly, the sensorless control techniques of permanent magnet motor are classified. The sensorless control techniques of permanent magnet motor for rotor initial position, zero-low speed range, medium-high speed range and full speed range are deeply described and compared. Finally, the development trend of sensorless control technology of permanent magnet traction motor is prospected.


2019 ◽  
Vol 21 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Juliana Romo-Buchelly ◽  
María Rodríguez-Torres ◽  
Fernando Orozco-Sánchez

Lactic acid (LA) is an organic compound used in several industries, such as food, textile, chemical, and pharmaceutical. The global interest  in  this  product  is  due  to  its  use  for  the  synthesis  of  numerous  chemical  compounds,  including  polylactic  acid,  a  biode-gradable thermoplastic and substitute for petroleum-derived plastics. An in-depth overview of the use of industrial and household wastes as inexpensive substrates in order to reduce the cost of LA production is presented. A review is carried out of the biotech-nological aspects that must be taken into account when using some wastes with high transformation potential to produce LA in a submerged  culture,  as  well  recommendations  for  their  use.  The  advantages  and  disadvantages  of  different  types  of  treatments used for the transformation of waste into suitable substrates are considered. Several methods of fermentation, as well as genetic strategies for increasing the production, are summarized and compared. It is expected that in a few years there will be many ad-vances in these areas that will allow greater large-scale production of LA using agroindustrial or household wastes, with potential positive economic and environmental impact in some regions of the planet.


1978 ◽  
Vol 22 (1) ◽  
pp. 331-331
Author(s):  
Stephen H. Ellis

The talk will deal with alternative methods of training customers to use new telephone services. Various measures of training effectiveness will be discussed with regard to their advantages and limitations. It will be argued that several measures—including cost—must be taken into account when evaluating training approaches. Two field studies will be described that examine several different types of training: (1) “Hands On” (demonstration) vs. “No Hands On” training; (2) Media-based vs. Lecture-based training; (3) “Live” training vs. Self-Instruction. The advantages and disadvantages of each approach will be described in terms of several measures of training effectiveness.


1980 ◽  
Vol 25 (92) ◽  
pp. 315-346 ◽  
Author(s):  
Charles Obled ◽  
Walter Good

AbstractDifferent statistical methods have been tested to answer the challenging problem of forecasting avalanche activity. For each approach, the theoretical background is briefly described, and the main advantages and drawbacks are discussed. The first method consists of a simple discriminant analysis applied to a sample of avalanche days against a sample of non-avalanche days. The second approach tries to take into account different types of avalanche phenomena associated with different types of snow and weather situations. It requires the development of an avalanche typology compatible with the available variables, and leads to a two-stage decision model. A given day is first allocated to a weather type, within which the proper model avalanche-non-avalanche is then processed. A third method, a local non-parametric one, consists of drawing, for the day under study and in an appropriate predictor space, its nearest neighbours from the sample file in order to get an estimate of the probability of avalanche occurrence. For each approach, the explanatory variables may be processed directly as quantitative continuous data or as qualitative categorized data. This removes the problems associated with the very asymmetric distribution of half of them, at the cost of a moderate loss of information. As a rule, the methods were calibrated and then applied to the winters 1972–73 and 1973–74 used as a test sample, thus allowing comparison of their respective potentials in operational forecast.


2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Mehrdad Khamooshi ◽  
Hana Salati ◽  
Fuat Egelioglu ◽  
Ali Hooshyar Faghiri ◽  
Judy Tarabishi ◽  
...  

Throughout the recent centuries, the limits of using energy resources due to the cost and environmental issues became one of the scientists’ concerns. Because of the huge amount of energy received by the Earth from the sun, the application of photovoltaic solar cells has become popular in the world. The photovoltaic (PV) efficiency can be increased by several factors; concentrating photovoltaic (CPV) system is one of the important tools for efficiency improvement and enables for a reduction in the cell area requirement. The limits of the PV area can reduce the amount of absorbing irradiation; CPV systems can concentrate a large amount of sunlight into a smaller one by applying lenses or curved and flat mirrors. However, the additional costs on concentrating optics and cooling systems made CPV less common than nonconcentrated photovoltaic. This paper reviews the different types of PV concentrators, their performance with advantages and disadvantages, concentration ratio, acceptance angle, brief comparison between their efficiencies, and appropriate cooling system.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 98
Author(s):  
Vikas Hakke ◽  
Shirish Sonawane ◽  
Sambandam Anandan ◽  
Shriram Sonawane ◽  
Muthupandian Ashokkumar

Nanomaterials have found many applications due to their unique properties such as high surface-to-volume ratio, density, strength, and many more. This review focuses on the recent developments on the synthesis of nanomaterials using process intensification. The review covers the designing of microreactors, design principles, and fundamental mechanisms involved in process intensification using microreactors for synthesizing nanomaterials. The microfluidics technology operates in continuous mode as well as the segmented flow of gas–liquid combinations. Various examples from the literature are discussed in detail highlighting the advantages and disadvantages of microfluidics technology for nanomaterial synthesis.


2020 ◽  
Vol 17 (3) ◽  
pp. 347-355
Author(s):  
Shweta Singh ◽  
Amar Nath Tiwari ◽  
S.N. Singh

Purpose For vector control of permanent magnet synchronous motor (PMSM) requires motor speed and rotor position estimation. The precision of the open-loop techniques of the stator flux and speed for vector control PMSM drive drops as mechanical speed decreases. The stator resistance and estimated stator flux values crisscross have a huge effect on the transient and steady-state performance of the drive at lower speed. The framework turns out to be increasingly strong against parameter crisscross and signal noises by using adaptive observers for estimation of speed and flux. Design/methodology/approach This paper presents a comparison of two-speed observers for the vector control PMSM drive: the sliding mode observer (SMO) and the model reference adaptive system (MRAS). A comprehensive analysis of SMO and MRAS respects dynamic, steady-state performance and robustness, affectability, stability and computational complexity has been introduced. The abstract of the advantages and disadvantages of both observer and their comparative analysis have also been discussed. Findings Dynamic performance steady-state performance and robustness, affectability and stability. Originality/value This paper presents a sensorless scheme, namely, MRAS and SMO for control of PMSM drive. These sensorless techniques have been tested for a PMSM motor drive and the motor performance was compared for both techniques. Matlab/Simulink based simulation results conclude that the adaptive methods improve dynamic response, reduces torque ripples and extended speed range.


Sensor Review ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Sari Lakkis ◽  
Rafic Younes ◽  
Yasser Alayli ◽  
Mohamad Sawan

Purpose – This paper aims to give an overview about the state of the art and novel technologies used in gas sensing. It also discusses the miniaturization potential of some of these technologies in a comparative way. Design/methodology/approach – In this article, the authors state the most of the methods used in gas sensing discuss their advantages and disadvantages and at last the authors discuss the ability of their miniaturization comparing between them in terms of their sensing parameters like sensitivity, selectivity and cost. Findings – In this article, the authors will try to cover most of the important methods used in gas sensing and their recent developments. The authors will also discuss their miniaturization potential trying to find the best candidate among the different types for the aim of miniaturization. Originality/value – In this article, the authors will review most of the methods used in gas sensing and discuss their miniaturization potential delimiting the research to a certain type of technology or application.


1980 ◽  
Vol 25 (92) ◽  
pp. 315-346 ◽  
Author(s):  
Charles Obled ◽  
Walter Good

AbstractDifferent statistical methods have been tested to answer the challenging problem of forecasting avalanche activity. For each approach, the theoretical background is briefly described, and the main advantages and drawbacks are discussed. The first method consists of a simple discriminant analysis applied to a sample of avalanche days against a sample of non-avalanche days. The second approach tries to take into account different types of avalanche phenomena associated with different types of snow and weather situations. It requires the development of an avalanche typology compatible with the available variables, and leads to a two-stage decision model. A given day is first allocated to a weather type, within which the proper model avalanche-non-avalanche is then processed. A third method, a local non-parametric one, consists of drawing, for the day under study and in an appropriate predictor space, its nearest neighbours from the sample file in order to get an estimate of the probability of avalanche occurrence. For each approach, the explanatory variables may be processed directly as quantitative continuous data or as qualitative categorized data. This removes the problems associated with the very asymmetric distribution of half of them, at the cost of a moderate loss of information. As a rule, the methods were calibrated and then applied to the winters 1972–73 and 1973–74 used as a test sample, thus allowing comparison of their respective potentials in operational forecast.


2020 ◽  
Vol 54 (2) ◽  
pp. 281-315
Author(s):  
Karolina Grzech ◽  
Eva Schultze-Berndt ◽  
Henrik Bergqvist

AbstractThis article provides an introduction for the collection of methodologically oriented papers comprising this Special Issue. We define the concept of epistemicity as used in descriptive linguistics and discuss notions related to it – some well-established, some more recent – such as evidentiality, egophoricity, epistemic authority and engagement. We give a preliminary overview of the different types of epistemic marking attested in the languages of the world and discuss the recent developments in the field of epistemic research focussing on methodologies for investigating epistemic marking. In the second part of the paper, we focus on the more practical side of epistemic fieldwork; the types of data that can be used in documenting linguistic expressions of epistemicity and best practices for data collection. We discuss the experimental methods that are used in the description of epistemic systems, both those developed for this particular purpose and those adapted from other types of linguistic research. We provide a critical evaluation of those materials and stimuli and discuss their advantages and disadvantages. Finally, we introduce the contributions to the Special Issue, discussing the languages studied by the authors of the contributions and the fieldwork methods they used in their research.


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