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.

Measurement of a variable frequency drive loss and efficiency using both calorimeter and powermeter

Abstract: Variable frequency drive efficiency plays an important role in green energy applications. However, how to accurately measure drive loss and efficiency is still a question to the industry. This paper reviews the powermeter method, calorimeter method, and factors that affect accuracy. After a calorimeter is constructed and calibrated, a variable frequency drive is tested using both methods. Test results are compared and uncertainty analysis is given.

Extra long distance belt conveyor variable frequency drive control system

Abstract: The utility model relates to an extra long distance belt conveyor variable frequency drive control system which comprises a handpiece frequency converter, a machine tail frequency converter and an industrial computer control system. A programmable logic controller (PLC) in connection with the machine tail frequency converter in control mode is further provided. The PLC is communicated with an industrial computer through a wireless control network, and is communicated with the machine tail frequency converter at the same time, and therefore power balance adjustments of the handpiece frequency converter and the machine tail frequency converter can be achieved. The handpiece frequency converter is communicated with the industrial computer through an RS485 network. By means of the balance adjustment of the extra long distance belt conveyor variable frequency drive control system, a real automatic real-time adjustment can be achieved, and effect of the adjustment is good.

Power factor control for high efficiency operation of an open-ended winding motor using a dual inverter drive with a floating bridge

Abstract: A novel control scheme is presented for an open-ended winding motor dual inverter drive, where a primary inverter is supplied from a dc power source and a secondary inverter is supplied from a floating dc capacitor with no power source Examination of the basic single phase equivalent circuit model of an induction machine reveals that near optimal motor efficiency is achieved at a relatively constant motor fundamental power factor over a wide range of motor loads and drive operating frequencies, eg 071 for the motor used in this work The drive control described uses the phase difference between the fundamental output voltages of the primary and secondary converters in order to control the motor's terminal voltage and to maintain a motor power factor of 071 This control is maintained over the full range of the motor's load and drive frequency settings The floating capacitor bridge voltage is regulated using PI feedback control, with the capacitor voltage error signal as the input and the amplitude modulation index of the primary inverter as the output The capacitor voltage reference signal is related to the per-unit drive frequency and measured current: as the motor's current or frequency changes, the capacitor's voltage reference is updated in a proportional manner to both parameters This control approach keeps the fundamental phase difference between the two inverters within a stable operating range, maintains the power factor of the main bridge close to unity, and improves the floating bridge's dc capacitor voltage stability during transient load changes The drive control performance is presented using detailed simulations and experimental testing; verifying the regulation of the floating capacitor's voltage as well as the predicted efficiency gains for the induction motor under constant power factor operation as compared with conventional drive control

Thermal Characterization of SiC Modules for Variable Frequency Drives

Abstract: In this paper, the advantages of SiC power modules to reduce peak junction temperature and power cycling effects are presented. A detailed power loss calculation and thermal model is developed and tested on a 480 V, 190A, 150 HP variable frequency drive (VFD) with SiC modules. A comparison between the SiC module and an equivalent rated Si module is presented to demonstrate the reduction in power cycling effects, particularly at low speed operation. Infrared (IR) imaging results and an analytical explanations of the phenomenon is provided. These results show that SiC inverters can be used for high torque and low speed applications. Also, the reduction in junction temperature swing improves reliability.

Analysis of elevator drives energy consumptions with permanent magnet machines

Abstract: Vertical transportations in a facility is one of the sources, which consume electrical energy. In this script, it examines the energy consumption with permanent magnet machines considering the actual system performance integrated with variable speed drive. Most common solution in the current trend of elevator technology is permanent magnet synchronous motor with variable frequency drive with direct current voltage bus intermediate. Energy consumption has been proposed to be understood with actual measurements and dynamic behaviour on various loads on the system is studied. Further, the proposal is to understand the regimes that would be higher efficient, which is analysed and presented.