Considerations when applying ASDs in continuous processes

Proceedings of the IEEE, 1982

Remntly, the outlook has changed slightly, due to temporary glut in the oil market.

E3S Web of Conferences

This paper deals with high-speed electrical drives utilizing power electronic converters (commonly abbreviated as ASD, VFD or VSD). Existing solutions vary mainly on the motor side while the power electronic converter is very similar for all cases. Various advantages as well as technical challenges are discussed and illustrated. At certain stages comparisons between conventional and high-speed drives are made. The paper summarizes the experience of a VFD manufacturer based on state of the art technology in medium voltage and multi-megawatt power range. The authors believe that main complexity around high-speed drives is the motor design while the VFD requires only small adaptations or can sometimes be used directly without any modifications of standard design. The technology readiness is evaluated to be on a medium to high level.

This paper is aimed at providing power/energy to the Adjustable speed drives during unsymmetrical voltage sag conditions by using supercapacitor as an energy storage system. The energy storage device will inject energy at the time of voltage sag and keep the ASDs in operation and hence avoid stoppage of the process in the processing industries. This method will be economical as compared to the existing methods and can be used as a retrofit in the existing industrial ASDs. Boost converter along with supercapacitor as an energy storage device has been used as the hardware to compensate the DC-link voltage because of its simplicity and cheap price. Based on the proposed topology, simulation model in MATLAB 7.5 (Sim Power Block set) has been developed for voltage unbalance conditions with supercapacitor as an energy storage device. The designed control technique is modelled, simulated and successfully implemented in the laboratory. The extensive simulation results supported by experimental results were provided to validate the proposed system.

IEEE Transactions on Industry Applications, 1990

The use of solid-state adjustable speed drives on ac and dc motors is constantlj increasing. Engineers are realizing the increased control of processes and energ) satings that can occur from correctlj applying these drives. This paper gites an overbiew of ac and dc drite theory, operation, and proper applications.

Voltage sags normally do not cause equipment damage but can easily disrupt the operation of sensitive loads such as electronic Adjustable Speed Drives (ASD's). Voltage sags cause a momentary decrease in DC-link voltage triggering an under voltage trip leading to nuisance tripping of adjustable speed drives (ASD's) employed in continuous-process industries which contributes to loss in revenue. A practical ride-through scheme for an adjustable speed drives based on supercapacitor during voltage sag has been presented in this paper. The supercapacitor maintains the ASD dc bus voltage under voltage sag condition. Energy storage module is connected to support the DC-link voltage during power system faults. The performance of ASD's under normal and power system faults is first simulated in MATLab Simulink and then experimentally verified. The Data AcQuisition boards (DAQ) of National Instruments along with LabVIEW software have been used to record the observed waveforms.

To characterize the performance and savings potential of variable speed drives (VSDs) retrofit on hydraulic pumps of plastic injection molding machines, twelve installations at seven sites were monitored. The objectives of the evaluation were to estimate energy and coincident demand savings for each installation based on short-term measurements performed at the sites, and to develop a model of savings as a function of pertinent operational parameters for the purpose of estimating savings for installations not measured. It was found that the savings associated with VSD retrofits on injection molding machines varies widely, and increases with the percentage of time the machine spends in the "idle" step of the molding sequence. The relationship between percent savings and percent idle time developed in this study can be used in conjunction with pre-or post-retrofit power and timing measurements to reliably predict savings. Pre-retrofit power, in cases where measurements are n...

IEEE Transactions on Industry Applications, 2005

In the European Union (EU), variable-speed drives (VSDs) were identified as the motor systems technology having the most significant electricity savings potential. In the EU, the identified economic electricity savings potential with the application of VSDs, by the year 2015, in industrial and tertiary sectors, are 39 and 8 TWh/year, respectively. However, only a small percentage of this potential is being used. In this paper the characterization of the current market of the VSDs is presented, including the average prices, the installation costs, and the total sales in each EU country, per power range. Selected VSD applications are presented. The key barriers to a wider application of VSDs are identified. In particular, the power quality and reliability problems associated with the use of VSDs are presented and possible technical solutions are discussed.

1993

This report was preparedas an accountof work sponsoredby an agencyof the i UnitedStatesGovernment.Neitherthe United StatesGovernmentnorany agency ! thereof,nor BattelleMemorial institute,nor any of their employees,makesany warranty, expressedor implied,or aslumesany legal liabilityor responsibilityfor theaccuracy, completeness, orusefulness of any information,apparatus,product, or processdisclosed, or representsthatits usewould not infringeprivatelyowned rights.Referencehereintoanyspecificcommercialproduct,process, or serviceby tradename,trademark, manufacturer, or otherwisedoesnot necessarily constitute or imply its endorsement,recommendation,or favoring by the United States Governmentor anyagencythereof,or BattelleMemorial Institute. The viewsand opinionsof authorsexpressed hereindo not necessarily stateor reflectthoseof the United StatesGovernmentor anyagencythereof.

These versatile and robust devices are the prime movers for the vast majority of machines. This chapter covers the basic construction, electrical and mechanical performance, motor acceleration, AC induction generator performance, efficiency of electric motors, rating of AC induction motors, duty cycles, cooling and ventilation, degree of protection of motor enclosures, methods of starting and motor selection. xii Preface Chapter 3: Power electronic converters. This chapter deals with the active components (e.g. diodes, thyristors, transistors) and passive components (e.g. resistors, chokes, capacitors) used in power electronic circuits and converters.

International Journal of Computer and Electrical Engineering, 2009

Electric power quality encompasses voltage transients, sags, swells, voltage distortions and momentary interruptions (outages) etc There are different techniques to enhance ride-through capability of ASD's during voltage sag conditions. These are aimed at maintaining the DC-link voltage constant by injecting energy from an external source. Ultracapacitors, as storage device, are of reduced size as compared to batteries and provide fast energy exchange. In this paper, the improved performance of ASD's with Ultracapacitors at DC-link during various electric power system faults is demonstrated using MATLAB simulation.and physical experiments were carried out to verify the correctness and validity of proposed ASD ride through topology and control strategies.The performance of ASD under healty and abnormal condition is first simulated in MATLab simulink and then the same are verified using designed hardware setup. The LABView (8.5) software and DAQ board has been used to record the generated waveforms during various power quality disturbances.