Energy efficient drive systems

Energy conservation is extremely important for the future of mankind. Energy derived from fossil fuel has serious environmental consequences and this needs attention of researchers as well as end users. Renewable energy is attractive but at the same time, fossil fuel based energy cannot be abruptly abandoned. In addition to encouraging use of renewable energy sources, the author of this paper believes that improving efficiency of electrical systems is equally important. The topic of improving system efficiency has not received its fair share of attention. Variable Frequency Drives (VFDs) are ubiquitous in industrial applications. Since they form a majority of motor controllers, they present a rich target for implementing novel ideas to achieve energy savings. Typical VFDs are voltage source type and they often suffer from poor power factor and lower overall system efficiency, especially when the motor is operating at light load conditions. This paper discusses interesting ideas on applying VFDs in an electrical environment to improve overall system efficiency with the intent of reducing the carbon footprint. Emphasis is also given to reducing standby power loss. This standby power loss can become an important part of the overall grid power wastage when numerous active front end converters in the form of wind power generating units or solar power inverters or other overhauling loads like oil beam pumps, form a major part of the power system.