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Assessment of the electric propulsion motor controller for the Colombian offshore patrol vessel
Published in C. Guedes Soares, T.A. Santos, Progress in Maritime Technology and Engineering, 2018
C. Morales, E. Insignares, B. Verma, D. Fuentes, M. Ruiz
The VFD is an equipment fitted with controlled semiconductor devices, receiving at the input electrical power with fixed voltage and frequency and delivering it with variable voltage and frequency at the output. This allows torque and rotational speed control of induction motors, since motor synchronous speed depends on motor pole number and supply frequency, as defined in Equation 1: ηs=-120×fep $$ \eta _{s} = \left( { - \frac{{{\text{120}} \times f_{e} }}{p}} \right) $$
Variable-frequency drives and harmonics
Published in Raymond F. Gardner, Introduction to Plant Automation and Controls, 2020
The VFD controller is essentially a specialized microprocessor-based programmable-logic controller that contains a user interface for starting, stopping, and setting motor speed and voltage/torque. An alphanumeric display, keypad, and indicator lights provide local status indication, and it is typically possible to scroll through the display to show operating parameters, such as rpm, frequency, voltage, current, power factor, and other useful information. The controller typically has signal connections for analog and digital inputs and outputs, and communication ports that can link to a distributed-control system. Speed-control setpoints can be set manually at the VFD panel, automatically from attached feedback instrumentation, or remotely from a distributed-control system.
A life extrapolation model using accelerated equivalent luminance and its application
Published in Quality Engineering, 2023
Jianping Zhang, Yinjie Zhang, Lei Sun, Jian Fu, Qing Zhou, Jun Hu, Cheng Bao, Siyi Chen
Vacuum fluorescent display (VFD) operates on the principle of cathodoluminescence, roughly similar to a cathode ray tube, but works at much lower voltages (Turney 1985). Each tube in a VFD has a phosphor coated anode that is bombarded by electrons emitted from the cathode filament (Shen and Ruan 2000). VFD emits very bright lights with high contrast and can support display elements of various colors (Zhang and Geng 2005), and has the advantages of clear and beautiful display, high reliability and good resistance to harsh environment (Shionoya, Yen, and Yamamoto 2006), particularly driving in vacuum environment, long service life, wide range of operating temperature, and low price (Li and Niu 2008; Ramasoot and Fotios 2012). Therefore, VFD products are widely used in industry, commerce, particularly in domestic appliance digitalization and so on (Qin et al. 2008). Nowadays, the screens of car dashboards and measuring instruments are developed by using excellent features of VFD, as shown in Figure 1.
Evaporative air cooler coupled with variable frequency drive for dehumidification of indoor air
Published in International Journal of Ambient Energy, 2019
R. Vijayakothandaraman, G. Sabari Girish, A. Prabhu
VFD is a motor-controlled device which drives an electric motor and varies the frequency and voltage supplied to the electric motor. Numbers of designs of regenerator are studied and also for analysing the regeneration process, a variety of theoretical models are employed. A parametric analysis of the system has been performed to calculate the rate of evaporation of water from the solution as a function of the system variables and the climatic conditions.