Topic
Variable-frequency drive
About: Variable-frequency drive is a research topic. Over the lifetime, 837 publications have been published within this topic receiving 5691 citations. The topic is also known as: VFD.
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27 Dec 2017
TL;DR: An integrated drive arrangement for a wastewater pumping system was designed and modeled to evaluate the energy saving gained from matching motors with Variable Frequency Drive and Programmable Logic Controller and a conclusion to replace on-off controllers currently used for most wastewater pumping systems is necessary.
Abstract: An integrated drive arrangement for a wastewater pumping system was designed and modeled to evaluate the energy saving gained from matching motors with Variable Frequency Drive (VFD) and Programmable Logic Controller (PLC). The proposed arrangement utilizes the affinity laws of centrifugal pumps to predict the performance of a pump under different rotational speed conditions. The specific energy (Es) is used as a measure of the cost effectiveness of the proposed pumping system.
Results have shown that a reduction of 10% in pump speed can save 30% in energy of maximum speed. The energy saving potential is carried out for a real-life case study, and a conclusion to replace on-off controllers currently used for most wastewater pumping systems is necessary. The total energy saving account for more than 50% when integrated drive system was applied for a combined sewer pump station.
Patent•
16 Sep 2011TL;DR: In this paper, a high voltage AC motor is configured to operate at an operating voltage in a high-voltage range of about 1.100 V to about 36.000 V.
Abstract: A drive system for driving a high voltage AC motor is provided. The high voltage AC motor is configured to operate at an operating voltage in a high voltage range of about 1.100 V to about 36.000 V. The drive system includes a low voltage variable frequency drive supplying AC voltage in a low voltage range and a step-up transformer coupled between the low voltage variable frequency drive and the high voltage AC motor.
Patent•
30 Jul 2020TL;DR: In this article, a temperature control system for a variable frequency drive (10, 100) is described, which includes a sealed enclosure (300), a power electronic component (330) and/or a power magnetic component (320) positioned inside the sealed enclosure, and a controller (400) configured to control a temperature of the power electronic components relative to an internal air temperature (Tair).
Abstract: A temperature control system (300) for a variable frequency drive (10, 100) includes a sealed enclosure (310), a power electronic component (330) and/or a power magnetic component (320) positioned inside the sealed enclosure (310), and a controller (400) configured to control a temperature of the power electronic component (330) and/or the power magnetic component (320) relative to an internal air temperature (Tair) inside the sealed enclosure (310) prior to an electrical energy application and operation of the power electronic component (320) and/or power magnetic component (320) to prevent condensation induced electrical failure of the power electronic component (330) and/or power magnetic component (320) utilizing a cooling system (340) and/or a heating system (350).
01 Dec 2014
TL;DR: In this article, an active series compensator is proposed to reduce harmonic currents at the PCC and regulate the DC link voltage at the input of the VSI, thus offering dual functionality.
Abstract: A voltage source inverter (VSI) is employed to implement a variable frequency drive (VFD) for obtaining desired speed-torque characteristics of an AC motor which is normally fed by a diode rectifier at the front end. These uncontrolled converters inject excessive harmonic currents in to AC mains resulting in detoriated power quality in terms of AC voltage waveform distortionat the point of common coupling (PCC) and increase losses in the distribution system. Because of voltage sag and swells, the DC link voltage is reduced and the drive needs to be derated. An active series compensator is proposed here which is capable of reducing harmonic currents at the PCC and regulating the DC link voltage at the input of the VSI, thus offering dual functionality.
26 Sep 2021
TL;DR: In this article, the efficiency of a phase-shifted transformer-based harmonic filter based on two transformers with 30 electrical degrees phase difference in reducing total harmonic distortion and maintaining these parameters within the acceptable range defined by the IEEE519 standard was investigated.
Abstract: Harmonics are among the serious problems that affect the power quality of an electrical system. However, harmonics nowadays are inevitable due to the ever-increasing number of Variable Frequency Drives (VFDs), Uninterruptible Power Supply (UPS) and other non-linear loads. In this regard, IEEE519 Standard specifies the allowable Total Harmonic Distortion (THD) and Total Demand Distortion (TDD) at a given point of common coupling (PCC). In this practical research, we have performed an extensive mathematical analysis to investigate the efficiency of a harmonic filter based on two transformers with 30 electrical degrees phase difference in reducing THD and TDD and maintain these parameters within the acceptable range defined by the standard. Analysis was carried out using actual data collected from the King Fahad Medical City Faculty of Medicine (KFMCFOM) Building Riyadh, Saudi Arabia. The results demonstrated that the phase-shifted transformer-based method removes some of the harmonic components caused by six-pulse VFDs and acts as a twelve-pulse VFD when connected with phase-shifted transformers in parallel. Accordingly, implementing the proposed method resulted in an over 50% reduction of THD and TDD values of the test system.