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.

Stretch wrapping machine with variable frequency drive torque control

Abstract: A method, apparatus and program product utilize a torque control algorithm constrained by a speed window to control the dispense rate of a packaging material dispenser when wrapping a non-cylindrical load with packaging material. In particular, a dispenser motor of the packaging material dispenser that is controlled by a VFD may be driven to maintain a substantially constant torque, while also constrained to operate within a speed window that is based at least in part on a rate of relative rotation between the packaging material dispenser and the load.

Modeling of Thermal Transient Processes in Frequency-controlled Induction Motor

Abstract: The paper presents a model of thermal transients in induction motor controlled via a variable frequency drive, which takes into account the operation of the motor at speeds different than the rated one. Experimental recording of motor heating curves at different angular speeds has been done, to verify the model.

Fuzzy PI modification for decision making simulation on a conveyor

Abstract: An important procedure in conceptual and design engineering is the ability to simulate processes using mathematical models to emulate, as far as possible, the reality of the physical model. An important feature of these models is to save time and money in the steps prior to construction, starting and parameter tuning of the project; the ability of each model to deal with different types of situations which it must handle, within and outside its operational limits, may show design failures that can be easily corrected in the early stages of conceptualization and designing. On the other hand, if a decision-making system is integrated, the model may be able to minimize the effects of disturbances, both internal and external, without the need of a human operator, which adds a level of automation to reduce errors and unwanted stops. This paper presents a LabVIEW based simulator for testing conveyors that handles and route unitary loads, it has the ability to simulate different models of three phase squirrel cage electric motors and show their responses to disturbances or unitary loads applied. The type of controller used is a Fuzzy PI through a variable frequency drive, which uses the theory of Variable Voltage Variable Frequency, it can establish the set point for speed operation in a short period of time and control it with variations smaller than 5% when a load is applied, it also maintain the torque in a variation smaller than a 5% to ensure the movement. The approach is to modify a decision making system, using the data for each motor, to adapt the fuzzy inference system to the particular operating conditions and ensure its control. An important issue is that the data used are expressed in the Per Unit System, this offers the advantage of a better visualization of the relationships of the results, working to each tested model of motor.

Variable Speed Wind Turbine with Doubly-Fed Induction Generator for a Regulated Output Frequency

Abstract: wind energy is one of the most important sources of renewable energy in the world. However, its main issue is that it's associated with dependence on the local environmental conditions, it's affected by wind speed, which causes oscillations in the output power of the generator, resulting in an unreliable system. Although using the fixed speed method leads to mechanical problems in case of turbine exposure to wind above the required level. Meanwhile, variable speed wind turbines were used with different types of generators depends on many causes. The doubly-fed induction (DFIG) generator is one of these generators. It's a wound rotor type induction generator it provides a variable speed system with fixed output power. This paper will be presenting the stand-alone performance of DFIG using variable frequency drive (VFD) to improve variable speed constant frequency (VSCF), it will be implementing the system practically and by MATLAB simulation.

Design and implementation of access monitoring and control based on SCADA system

Abstract: The supervisory control and data acquisition (SCADA) system is considered a pioneer system in the field of remote education. Three laboratories are designed for the alternating current (AC) Machine Lab, while the programmable logic controller (PLC) is used to connect the system to the Internet by designing an interface to the system through the DIAView program, where each student has his account and a specific time to implement the experiment and write the result in a report window. In this system, teacher and students can assess the system through a specific window. The teacher can access, control and monitor the performance of the students. The teacher can evaluate each student. Student can access and control the laboratories. The methods to turn on the single-phase induction motor include capacitors, auto transformer and variable frequency drive (VFD). VFD is considered an advanced system at present, to which an intelligent system has been added. Moreover, an overload protection system has been introduced, where it would shut down the Lab and show an error message. The system can work as a local area and public area when connected to the university of KUFA system Moodle server.