Modern Power Electronics and Drivers

Figure 1: Structure of drive system Load is the most important component. All other units are arranged to serve the requirement of the load. Any design begins with a list of specifications for the load. This depends on the type of the load and its environment. We need to answer several questions before preparing specifications. Eg: Whether one, two or four quadrant operation is necessary Whether servo or adjustable speed action is necessary Whether breaking energy is to be dissipated or returned back to the utility Whether a soft or hard start is suitable What are the range of speed and the resolution of the speed control? What are maximum torque? Is there a space restriction? Is there a noise level restriction? Is there some starting current restriction? Is there any EMI (Electro Magnetic Interference) restriction? Is there supply end restrictions? (Eg: Total Harmonic Distrotion)? Whether the energy efficiency is a prime consideration and many more. The components in ...