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Electric Motors and Drives
Published in Barney L. Capehart, William J. Kennedy, Wayne C. Turner, Guide to Energy Management, 2020
Barney L. Capehart, William J. Kennedy, Wayne C. Turner
Another common method of controlling speed is to use induction motors combined with VFDs. Induction motors are widely used in industrial applications because of their inherent advantages in terms of cost, reliability, availability, and low maintenance requirements. Mechanics and operators are usually familiar with these motors, which facilitate repair and maintenance tasks. Combining an in-service motor with a VFD provides facilities with an effective speed control technology that does not require the use of a different type of motor. However, not all in-service induction motors can be combined with a VFD; engineers should evaluate motors case-by-case to see if such combinations are feasible. Misapplying VFDs to in-service motors can quickly cause motor failures.
Background on Condition Monitoring Techniques
Published in Nordin Saad, Muhammad Irfan, Rosdiazli Ibrahim, Condition Monitoring and Faults Diagnosis of Induction Motors, 2019
Nordin Saad, Muhammad Irfan, Rosdiazli Ibrahim
Induction motors are often exposed to operating environments that may not be ideal and in some cases are even harsh, such as in insufficient cooling areas, inadequate lubrication, structure vibration, overload, frequent motor starts and stops, etc. In such situations, induction motors are subjected under detrimental stresses, which lead to failure [7,8]. Because of the significant role that motors play in many applications, improvement in the reliability of the motors is required. Induction motors are suitable for almost all commercial and industrial applications due to their simple construction with fewer parts, which reduces the cost of maintenance. Applications in both variable speed drive and constant speed drive are the main uses of induction motors. The reasons why electric motors can fail have been commonly reported as follows [9,65,66]:
Electric Motors and Drives
Published in Barney L. Capehart, Wayne C. Turner, William J. Kennedy, Guide to Energy Management, 2020
Barney L. Capehart, Wayne C. Turner, William J. Kennedy
Another common method of controlling speed is to use induction motors combined with VFDs. Induction motors are widely used in industrial applications because of their inherent advantages in terms of cost, reliability, availability, and low maintenance requirements. Mechanics and operators are usually familiar with these motors, which facilitate repair and maintenance tasks. Combining an in-service motor with a VFD provides facilities with an effective speed control technology that does not require the use of a different type of motor. However, not all in-service induction motors can be combined with a VFD; engineers should evaluate motors case-by-case to see if such combinations are feasible. Misapplying VFDs to in-service motors can quickly cause motor failures.
Adaptive Controller for Bridgeless New SEPIC Integrated Landsman Converter for PFC in Induction Motor
Published in Electric Power Components and Systems, 2023
R. Suguna, S. Tamil Selvi, K. Mohana Sundaram
The supplied input AC voltage is rectified using bridgeless SEPIC-Landsman converter and it is provided to the VSI. In case of a VSI, its output voltage is altered by varying its input DC supply, whereas its output frequency is altered by varying the inverter time period using the Cascaded T2-FLC. The application of Cascaded T2-FLC, improves the output signal of the VSI by reducing the harmonics and ripple output torque. The Induction motor power input is expressed by the following equation, where the terms and refers to the fundamental component of motor phase voltage and current, respectively. A phase angle between and is represented by ϕ. An extensive range of speed variation is achieved by adjusting the electrical frequency input of the induction motor. The proposed system maintains a constant volts/hertz ratio by allowing the simultaneous control of both voltage and frequency, thus ensuring that the current flow is maintained according to the full speed conditions.
Accelerating Time–Current Curve Computation of Induction Motor from Manufacturer Data
Published in IETE Journal of Research, 2021
Induction motors have been mostly used due to their simplicities, high reliabilities, and almost free maintenances. Under a strong grid connection, the cheapest way to start up high-voltage induction motors is a direct-on-line method [1]. Due to a high sustained starting current, the motors must accelerate to a full speed within the locked-rotor withstand time or safe stall time, irrespective of the types of loads [2–5]. Hence, the ATC curves representing the starting and running ampere characteristics of induction motors for given inertia and mechanical load curve are important for setting their overcurrent protective devices against overheating [6–8]. For example, to selectively coordinate the protective devices with motor starting characteristics, their tripping curves must be superimposed on the motor’s ATC curve. The chosen tripping characteristics of any overcurrent protective devices should be situated below the thermal limit curve but above the ATC curve [9–11]. Moreover, various comparisons of overcurrent protective devices against the motor’s ATC curve are often done to ensure a proper coordination. So, the ATC curve is very much required for the correct setting and coordinating of overcurrent protections.
Design and analysis of a novel wound rotor for a bearingless induction motor
Published in International Journal of Electronics, 2019
Zebin Yang, Qifeng Ding, Xiaodong Sun, Jialei Ji, Qian Zhao
Induction motors are widely used in the field of electrical drives area for its advantages of simple structure, reliable operation, low price as well as durability (Chen, Yu, Xu, & Xu et al., 2012; Chiba & Asama, 2012; Sugimoto, Shimura, & Chiba, 2017). The traditional induction motor is supported by mechanical bearings and the friction not only causes loss to the bearing itself but also raises the temperature, shortening the motor’s working life (Rodriguez & Santisteban, 2011). Utilizing the structure similarity between the magnetic bearing and the stator, a bearingless induction motor (BIM) stator is embedded with an extra suspension force winding on the basis of the common induction motor that only has one torque winding. By controlling the current in torque winding and suspension winding separately, it is possible for the BIM to achieve frictionless rotation and stable suspension (Sinervo & Arkkio, 2014; Sun, Chen, Yang, & Zhu, 2013; Yang, Zhang, Sun, & Ye, 2018). Compared with traditional induction motors, the BIMs’ advantages of no mechanical friction, wear, no lubrication, long service life (Ding, Ni, Wang, & Deng, 2018; Sun, Shi, Chen, & Yang, 2016) make it has more broad application prospects in the aerospace, high-speed hard disk, the flywheel energy storage, biological medicine, sterile and pollution-free operation of special electric fields (Han, Wang, & Li et al., 2015; Sinervo & Arkkio, 2014; Yang, Wang, Sun, & Ye, 2018).