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.
Papers published on a yearly basis
Papers
More filters
Patent•
21 Dec 2018
TL;DR: In this article, a variable-frequency drive speed control precision detection device was proposed, in which a moving plate can move leftwards and rightwards to fix a variable frequency drive and prevent it from moving during detecting; a water pump is connected with a water-cooling block and a heat exchanger through a circulating fluid pipeline, and the circulating fluid circulates in a sealed environment.
Abstract: The invention relates to a variable-frequency drive speed control precision detection device According to the variable-frequency drive speed control precision detection device, by rotating a rotatinghandle, a moving plate can move leftwards and rightwards to fix a variable-frequency drive, and the variable-frequency drive is prevented from moving during detecting; a water pump is connected witha water-cooling block and a heat exchanger through a circulating fluid pipeline, and thus circulating fluid circulates in a sealed environment; the water-cooling block makes contact with all equipmentto absorb heat, the heat is brought into the heat exchanger through flowing of the circulating fluid, the heat exchanger conducts heat dissipating and cooling on the circulating fluid, thus heat dissipating of all the equipment is achieved, and the service life of all the equipment is prolonged; through an arranged transformer, the detected voltage can be changed to adapt to the voltage of the transformer, thus the applicability of the detection device is improved, and the transformer is protected; through an arranged heat dissipating fan, hot air generated in an equipment box can be pumped out, and thus the temperature in the equipment box is decreased; and through an arranged indicator light, the working condition of the detection device can be displayed, and when work is abnormal, a user can be reminded to pay attention
Patent•
06 May 2021
TL;DR: The bottom tier of a conveyor belt arranged in a spiral stack is supported by and driven by inner and outer drive chains (28) and (30) as mentioned in this paper, and each of the motors is controlled by a separate variable frequency drive unit.
Abstract: The bottom tier (24) of a conveyor belt (22) arranged in a spiral stack (26) is supported by and driven by inner and outer drive chains (28) and (30). The inner and outer drive chains are supported on and ride along support rails (32) and (34). The inner and outer drive chains are driven by a drive system (35) composed of inner and outer drive systems (36) and (38), each including a drive motor with a drive gear engaged with the inner and outer drive chains. Each of the motors is controlled by a separate variable frequency drive unit (114) and (116) which in turn are controlled by a control system (44). The control system (44) also controls the operation of a lubrication system (40) that supplies lubricant to the drive chains.
Patent•
29 Oct 2020
TL;DR: In this paper, a system for hydraulic fracturing is described, which involves a mobile hydraulic fracturing subsystem including a variable frequency drive (VFD) (12) electrically coupled to a generator (50).
Abstract: System for hydraulic fracturing is provided. The system may involve a mobile hydraulic fracturing subsystem including a variable frequency drive (VFD) (12) electrically coupled to a generator (50). An electric motor (14) is driven by VFD (12). Harmonic mitigation circuitry (16) is configured to mitigate harmonic distortion by VFD (12). A hydraulic pump (20) is driven by motor (14) to deliver a pressurized fracturing fluid. VFD (12), harmonic mitigation circuitry (16), motor (14) and hydraulic pump (20) may be arranged on a mobile platform (24) so that a subsystem so arranged can be transportable from one physical location to another. In some disclosed embodiments, the hydraulic fracturing subsystem may be fitted on mobile platform (24) having size and weight not subject to laws or regulations requiring a permit and/or accompaniment by an escort vehicle to travel on a public highway, such as public highways in the United States and/or Canada.
Patent•
10 Mar 2014
TL;DR: In this article, a system of compressor crankcase heating comprises a compressor with a housing, where a compression mechanism is placed, driven by an electric motor, when the compressor is switched on, and not driven with a motor when the compressors are switched off.
Abstract: FIELD: power engineering.SUBSTANCE: system of compressor crankcase heating comprises a compressor with a housing, where a compression mechanism is placed, driven by an electric motor, when the compressor is switched on, and not driven with an electric motor, when the compressor is switched off. The system also comprises a converter of a variable frequency drive, which provides for operation of the electric motor, when the compressor is switched on, by control of frequency of voltage supplied to the electric motor, and supplies electric current to the stator of the electric motor to heat the compressor, when the compressor is switched off. Also the method is provided to heat the compressor crankcase.EFFECT: invention makes it possible to ensure more efficient controlled heating of a compressor crankcase.20 cl, 8 dwg
Patent•
06 Sep 2019
TL;DR: In this article, a system for assessment of multiple faults in induction motors was proposed, consisting of a high magnitude fundamental component, fault frequency components, and noise and amplitude estimation block for estimation of fundamental signal further conditioned with input signal to motor.
Abstract: A system for assessment of multiple faults in induction motors, said motor motor being supplied from a 3-phase supply (100) using a variable frequency drive (VFD), said system comprising: a current sensor (102) for sensing a single phase stator current; an anti-aliasing filter (105) for subsequent conversion of sensed current into digital format using an analog to digital converter (106), said acquired signal consisting of a high magnitude fundamental component, fault frequency components, and noise and amplitude estimation block (107) for estimation of fundamental signal further conditioned with input signal to motor in order to obtain a conditioned input signal for estimation of slip and speed of motor to determine a fault search band correlative to fault frequency components, said fault frequency components estimated by means of a spectral estimator to determine if said motor comprises rotor faults, eccentric specific faults, bearing faults, and / or stator faults.