This paper deals with a few major application of AC motors and drives with special controls in steel plants. Application of AC drives for electrically operated overhead crane have been discussed in details. Application of AC drives has reduced the maintenance expenses and a large amount of power is saved. AC power is also used for high frequency welding and other special applications. Large numbers of high power AC motors are used in steel industries which require control of speed to suit the process requirement. In a steel plant, power electronics plays an important role in process improvement and dimensional control of rolled products. Proper selection of drives not only saves electrical energy but also produce quality products. Advancements in the field of drives and control techniques are responsible for improvements in the quality and yield of steel products.

/pdf/application-of-ac-motors-and-drives-in-steel-industries-1gycld8y5d.pdf

Application of AC motors and drives in Steel Industries

The mechanical arm (manipulator) of a robot can be controlled using image processing techniques. The system detects user motion and colour in real time. The main goal is to gather user motions and colour from a video stream captured by a webcam facing the user. To track the motion of the user's hand; it needs to select the Image feature that is both robust and the one which is ideal for real time tracking of moving points across consecutive image frames. The intuition is that if it randomly picks a point on a uniform surface to track, and then it not likely to find the same point in the next frame. On the other hand, if it chooses a unique point that is more invariant under motion or luminance changes, it has more chance of finding the point again and the tracking will be more robust. The feature Extraction and the tracking algorithm are more efficient in this system. The colour detection is done by converting the image into grayscale and the intensity is been calculated and the respected colour is been tracked, by doing so the colour of the object is been detected, the user wears a hand glove and makes gestures before the camera hence the system detects the colour and the motion of the user and puts into action.

An integrated virtual control of robot manipulator for automated industrial environment

Elaboration of the Load-Equalization System of the Electric Drive of the Main Hoist of a Bridge Crane

Napędy przemiennikowe suwnicy chwytakowej

Conventional AC operated electric overhead travelling (EOT) cranes uses slip ring induction motors whose rotor windings are connected to a power resistance. Speed control is performed by changing the rotor resistance in 3 to 4 steps by power contactors. Reversing is performed by changing the phase sequence of the stator supply through line contactors. Braking is achieved by a plugging operation. A crane control system has been developed using a variable voltage variable frequency drive and a programmable controller which has the advantage of continuous speed control; reversing is achieved by changing the phase sequence through an inverter. The main advantages of thi system are precise positioning, energy saving and increased motor life. This paper focuses on the application of variable voltage variable frequency induction motor drives in crane applications.

A.K. Paul

Papers

AC operated EOT crane control with variable voltage variable frequency drive