Motors solid-state technology

In the following text we have discussed bow. with the application of varying supply parameters (V and/), one can alter the characteristics of a fixed parameter induction motor in any desired way. We then deal with the application of solid-state technology to obtain the variations in the fixed supply parameters to achieve the required controls in an a.e. machine. 

Induction motors, both, squirrel cage and slip-ring, can be easily controlled to achieve the required characteristics by applying solid-state technology. 

A very important feature of solid-state technology is energy conservation in the process of speed control. The slip losses that appear in the rotor circuit are now totally eliminated. With the application of this technology, we can change the characteristics of the motor so that the voltage and frequency are set at values just sufficient to meet the speed and power requirements of the load. The power drawn from the mains is completely utilized in doing useful work rather than appearing as stator losses, rotor slip losses or external resistance losses of the rotor circuit. 

Tbe use of special motors was more relevant until the 1980s. when solid-state technology was still in its infancy and wa.s not so widely applied. With the advent of static drives, as discus.sed in Sections 6.2-6.4, the use of standard motors is gradually becoming more common for all these applications. The drive it.self can alter the supply parameters to the required level to make a standard motor operate and perform within desired parameters, besides conserving energy. The purpose of describing a few of these applications is only to indicate their non-standard features, where a standard motor with normal controls may not be able to perform the required duties. 

---