Power Electronics Summary and Future Developments
Much of the historical discussion in previous posts have described the special semiconductors used for power conversion circuits. The special energy processing applications addressed by power electronics have also been described. Not long ago, the devices were in many ways the limiting factor in converter design. The fast pace of change in devices has brought about entire new families of power electronic applications, and devices are less and less constraining. The important classes of power electronic components routinely reach power handling levels of at least equal to household appliance loads, to small industrial process, or to elements of automobiles. Today’s designer chooses a circuit and device because it is a good match for the application. Many alternatives are often available. It has been said that power electronics is a ‘device-driven’ field. This is not longer the case. Now, the field has become a true ;applications-driven’ subject. This trend will continue into applications across all aspects of modern life including industrial robots, portable electronics and communications, electric vehicles, and alternative energy sources.
Key opportunities include:
- Electronic AC motor drives. These offer a revolution in energy conservation and industrial processes. It is now possible to use sophisticated controls for refrigerators, fans, conveyors, and robotic arms. Energy usage can be reduced considerably in nearly all applications by the use of smart devices.
- Electric transportation. Power electronics is the cornerstone of modern initiatives for electric, hybrid, and alternative vehicles. Today, power electronics can run commercial electric cars at over 130 mph. Battery energy can be conserved well enough for practical cars to reach over 260 miles of range with conventional batteries. Novel ideas and innovation are needed for the best designs.
- Electrical systems for high-efficiency lighting and appliances. Modern fluorescent lights are many times more efficient that incandescent bulbs. The require high-frequency power electronics for optimum operation. LED lighting is currently pushing the boundaries of efficient lighting and requires similar power conversion for DC operation. Similar new developments extend to appliances such as microwave ovens, washer/dryer sets, and nearly every other major home energy consumer.
- Power supplies for telecommunications. There are billions of people without telephones or means of global communication. Many developing countries do not plan to build expensive hardwired networks. Satellite links, wireless communications, and other new technologies must be integrated with existing equipment. Each different application has unique power supply needs.
- Power supplies in battery-based portable products. Energy conservation is crucial in battery systems. Proper use of power electronics can easily make a 50% difference of more in battery life. Converters for applications below 5 V, levels typical of portable electronics, provide a special challenge.
- Power electronic application in electric utility networks. It is possible to extend conversion advantages to extremely high power levels. Active systems with fast control of all energy flows can be imagined. This gives a tremendous range of opportunities for lower cost and more efficient electricity distribution.
Novel power electronic methods are being applied to audio amplifiers, cell phones, and microprocessors. The list is long, and there is need for skilled engineers who can apply the methods in unconventional ways.