Ride through testing of variable speed drive due to  voltage sag types (types I, II and III)

Variable speed drives (VSDs) are widely used in various applications mainly in process industry need constant rotational speed. It is developed from power electronic components thus saving energy in its operation. Unfortunately it is susceptible against power quality problem for example voltage sags. The VSD may be disruption or drop out when it is supplied by voltage sags and it is determined by sag characteristics. This study is to investigate effect of voltage sags Types I, II and III on VSD through laboratory testing. The voltage sags characteristics are generated from voltage sag generator (Shaffner 2100 EMC). The effects are presented in susceptibility curves in disruption and drop out conditions. The curves resulted are evaluated by standard curve recommended. Test results show that voltage sag Type I cause the VSD disruption only, whereas two types sag other result in the VSD disruption and also drop out. Evaluation results explain a few test points are in operation area for disruption condition whereas test points for dropping out far below the threshold recommended. Hence the VSD has good quality to voltage sags.

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Impact of voltage sags and continuous unbalance on variable-speed drives

The XIX International Conference on Electrical Machines - ICEM 2010 ◽

10.1109/icelmach.2010.5607961 ◽

2010 ◽

Cited By ~ 2

Author(s):

Fernando J. T. E. Ferreira ◽

Anibal T. de Almeida ◽

Ge Baoming

Keyword(s):

Voltage Sags ◽

Variable Speed ◽

Variable Speed Drives

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Dual 3-Phase Bridge Multilevel Inverters for AC Drives with Voltage Sag Ride-through Capability

Energies ◽

10.3390/en12122324 ◽

2019 ◽

Vol 12 (12) ◽

pp. 2324

Author(s):

Vitor Fernão Pires ◽

Joaquim Monteiro ◽

José Fernando Silva

Keyword(s):

Control System ◽

Supply Voltage ◽

Voltage Sag ◽

Voltage Sags ◽

Power Supply Voltage ◽

Multilevel Converters ◽

Variable Speed Drives ◽

Ac Drives ◽

Ac Motor ◽

Drive And Control

One of the main power quality issues that can affect variable speed drives (VSDs) is the occurrence of voltage sags on their AC power supply. Voltage sags can affect the inverter nominal operation, leading to a malfunction of the AC motor. This paper presents an inverter with resilient capability to voltage sags. The topology consists of two conventional three-phase bridge inverters arranged to require just a single DC source. This inverter is also characterized by a voltage multilevel operation, providing the full advantages of multilevel converters without the need for level balancing. Associated with this AC motor driver, a control system based on a field-oriented controller with a vector voltage modulator that will enable voltage sag ride-through capability is proposed. The proposed control system does not require any changes in the occurrence of voltage sags. To verify the characteristics of the proposed drive and control system, simulation tests are provided. Simulation results confirm the voltage sag resilient capability of the proposed multilevel converter.

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Power electronics and variable speed drives

Power Engineering Journal ◽

10.1049/pe:20000408 ◽

2000 ◽

Vol 14 (4) ◽

pp. 190-191

Keyword(s):

Power Electronics ◽

Variable Speed ◽

Variable Speed Drives

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Опыт использования частотных преобразователей на объектах ООО «Водоканал»

Vodosnabzhenie i sanitarnaia tehnika ◽

10.35776/mnp.2020.04.08 ◽

2020 ◽

Author(s):

Sergei, Rybel’ ◽

V. Kuninin ◽

S. Gerasimov ◽

A. Bakushin

Keyword(s):

Inrush Current ◽

Electric Motors ◽

Variable Speed ◽

Variable Speed Drives ◽

Technical Device ◽

Advantages And Disadvantages ◽

Subsequent Period ◽

Pumping Stations ◽

Current Water ◽

Pumping Equipment

Приведен опыт применения частотно-регулируемых электроприводов на насосных станциях ООО Водоканал г. Новокузнецка. Приводятся преимущества и недостатки данного технического устройства. Показано, что в настоящее время использование частотно-регулируемых приводов позволило снизить потребление электроэнергии более чем на 20, уменьшить затраты на ремонт и обслуживание, повысить срок службы электродвигателей, уменьшить величину пускового тока, снизить утечки воды и нагрузку на насосное оборудование и трубопроводную арматуру. Применение частотно-регулируемых электроприводов оправдало себя и в тех случаях, когда требуется регулирование параметров для обеспечения технологии (регулирование скорости, производительности и т. д.), приведение параметров оборудования к требуемым значениям без его замены (в расчете на увеличение загрузки оборудования до номинала в последующий период), компенсация суточной неравномерности потребления воды.The experience of using variable speed drives at the pumping stations operated by Vodokanal LLC in Novokuznetsk is presented. The advantages and disadvantages of this technical device are specified. It is demonstrated that currently, the use of variable speed drives provides for reducing the energy consumption by more than 20, reducing the repair and maintenance costs for improving the service life of electric motors for reducing inrush current, water leaks and the load on the pumping equipment and pipeline valving. The use of variable speed drives has paid off even in case where adjusting the parameters to ensure the technology (velocity, performance, etc.) bringing the equipment parameters to the required values without replacing it (in order to increase the equipment load to the nominal value for the subsequent period) compensating for daily irregularities in water consumption are required.

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Dropout from an internet-delivered CBT Intervention for Adults with Depression and Anxiety: A Qualitative Study (Preprint)

10.2196/preprints.26221 ◽

2020 ◽

Author(s):

Kate Lawler ◽

Caroline Earley ◽

Ladislav Timulak ◽

Angel Enrique ◽

Derek Richards

Keyword(s):

Online Communication ◽

Structured Interview ◽

Routine Care ◽

Drop Out ◽

Group Differences ◽

Dropping Out ◽

Completion Rates ◽

Depression And Anxiety ◽

Lower Treatment ◽

Perceived Change

BACKGROUND Treatment dropout continues to be reported from iCBT interventions and lower completion rates are generally associated with lower treatment effect sizes. However, evidence is emerging to suggest that completion of a pre-defined number of modules is not always necessary for clinical benefit nor considerate of the needs of each individual patient. OBJECTIVE The study aimed to carry out a qualitative analysis of patients’ experiences of an iCBT intervention in a routine care setting in order to achieve a deeper insight into the phenomenon of dropout. METHODS Fifteen purposively sampled participants (8 female) from a larger parent RCT were interviewed via telephone using a semi-structured interview schedule that was developed from the existing literature and research on dropout in iCBT. Data was analysed using the descriptive-interpretive approach. RESULTS The experience of treatment leading to dropout can be understood in terms of ten domains: Relationship to Technology, Motivation to Start, Background Knowledge and Attitudes towards iCBT, Perceived Change in Motivation, Usage of the Programme, Changes due to the Intervention, Engagement with Content, Experience Interacting with the Supporter, Experience of Online Communication and Termination of the Supported Period. CONCLUSIONS Patients who drop out of treatment can be distinguished in terms of their change in motivation: those who felt ready to leave treatment early and those who had negative reasons for dropping out. These two groups of participants have different treatment experiences, revealing potential attributes and non-attributes of dropout. The reported between group differences should be examined further to consider those attributes that are strongly descriptive of the experience and regarded with less importance those that have become loosely affiliated.

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Adjustable frequency invertors and their application to variable-speed drives

Electronics and Power ◽

10.1049/ep.1964.0369 ◽

1964 ◽

Vol 10 (11) ◽

pp. 389 ◽

Cited By ~ 2

Author(s):

D.A. Bradley ◽

C.D. Clarke ◽

R.M. Davis ◽

D.A. Jones

Keyword(s):

Variable Speed ◽

Variable Speed Drives

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Conversores de freqüencia VSI-PWM submetidos a afundamentos temporários de tensão ("voltage sags")

Sba Controle & Automação Sociedade Brasileira de Automatica ◽

10.1590/s0103-17592003000100006 ◽

2003 ◽

Vol 14 (1) ◽

pp. 50-57

Author(s):

Paulo C. A. Leão ◽

José C. de Oliveira ◽

Kleiber D. Rodrigues

Keyword(s):

Voltage Sag ◽

Voltage Sags

Este artigo tem por objetivo analisar a interdependência entre a operação de conversores de freqüência tipo VSI-PWM e uma das manifestações mais comuns para a perda de qualidade de um suprimento elétrico, qual seja, a ocorrência do fenômeno denominado por afundamento temporário de tensão ou "voltage sag". São apresentados resultados de simulações, realizadas no Simulador Saber, de um sistema típico submetido a afundamentos de tensões simétricos e assimétricos. Resultados de ensaios em laboratório também são fornecidos com vistas à validação dos resultados computacionais. Aspectos relacionados com a capacidade "ride-through" dos conversores e correspondentes arranjos de proteção são também considerados.

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Common-Mode Voltage Harmonic Reduction in Variable Speed Drives Applying a Variable-Angle Carrier Phase-Displacement PWM Method

Energies ◽

10.3390/en14102929 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2929

Author(s):

Abraham Marquez Alcaide ◽

Vito Giuseppe Monopoli ◽

Xuchen Wang ◽

Jose I. Leon ◽

Giampaolo Buticchi ◽

...

Keyword(s):

Carrier Phase ◽

Harmonic Distortion ◽

Harmonic Spectrum ◽

Hydraulic Systems ◽

Variable Speed ◽

Common Mode ◽

Variable Speed Drives ◽

Phase Displacement ◽

Common Mode Voltage ◽

External Component

Electric variable speed drives (VSD) have been replacing mechanic and hydraulic systems in many sectors of industry and transportation because of their better performance and reduced cost. However, the electric systems still face the issue of being considered less reliable than the mechanical ones. For this reason, researchers have been actively investigating effective ways to increase the reliability of such systems. This paper is focused on the analysis of the common-mode voltage (CMV) generated by the operation of the VSDs which directly affects to the lifetime and reliability of the complete system. The method is based on the mathematical description of the harmonic spectrum of the CMV depending on the PWM method implementation. A generalized PWM method where the carriers present a variable phase-displacement is developed. As a result of the presented analysis, the CMV reduction is achieved by applying the PWM method with optimal carrier phase-displacement angles without any external component and/or passive filtering technique. The optimal values of the carrier phase-displacement angles are obtained considering the minimization of the CMV total harmonic distortion. The resulting method is easily implementable on mostly off-the-shelf mid-range micro-controller control platforms. The strategy has been evaluated in a scaled-down experimental setup proving its good performance.

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