With the rapid increase in the world population over the last decade, which has now crossed 8 billion, the demand for energy is also witnessing a similar growth. By 2040, the global energy demand is expected to increase by approximately 19 percent. Out of this, 40 percent of the current energy requirement is in the form of electrical energy and will reach 60 percent by 2040, thus taking up more than half of the total energy demand.
Currently, more than half of the global electricity demand is met using fossil fuels, leading to adverse effects on the natural environment. The burning of fossil fuels increases the emission of greenhouse gasses, causing an increase in global warming that poses a massive risk to the lives of humans and other species on Earth.
The effects of global warming have increased the interest in adopting greener and more renewable energy sources like solar, wind, and hydro. All these sources are available in ample quantity in nature, and they produce byproducts like water, which are also harmless and can be reused for other applications. Even with the advantages of these renewable sources, their market share growth still seems to be very slow compared to fossil fuels. This is mainly due to the mismatch in energy demands and using gas or coal power plants as a buffer to meet these variations.
Ultimately, the goal is to use energy sustainably and minimize energy wastage as much as possible. Developing technologies and strategies for energy savings becomes crucial to tackle this issue, as we cannot rely only on renewable sources. According to the Canadian Association of Petroleum Producers (CAPP), the world would have required twice as much energy to fulfill the current demands if it weren’t for continuous improvements in energy efficiency. With energy-efficient converters based on power electronics, the power conversion efficiency can reach up to 99 percent in some cases, more about which is discussed further.
Energy losses from generation to utilization. (Image credit: reasearchgate.net)
Power Electronics in Adjustable Speed Drives (ASD)
Most applications involving physical movement will have an electric motor powering the whole mechanical system. More than 40 percent of the total electrical energy is consumed by electric motors alone. The energy share of motors is even higher in industries at around 65 percent due to applications like converter belts, lifts, motion control systems, etc. Some applications require varying speed and torque, which is where ASDs are most efficient, while other applications with constant load profiles have different types of drives. Therefore, there is a huge opportunity for lowering global energy consumption by creating energy-efficient motor driving systems.
Compared to traditional motor drives, power electronic-based drives consume considerably less energy as the energy lost in heat is minimized. Even the traditional motor starters, like those based on resistor banks, are highly inefficient and offer poor performance as per the current standards. With the introduction of solid-state power electronics components like thyristors, SCRs, IGBTs, and MOSFETs, efficient motor starters are developed that are retrofit friendly. The SMCV6080 induction motor reduced voltage starter from Celduc Relais is one such product that offers soft-start and soft-stop features. It uses six thyristors to provide smooth control over the motor. With integrated microcontrollers, this starter can also provide diagnostic and self-test functions.
Energy-Efficient Lighting with Power Electronics
Electric lighting systems are the next major consumer of electrical energy due to their continuous usage during nighttime and even during the day, especially in places with less sunlight. Electric lighting accounts for around 22 percent of global electrical energy usage and thus has a huge potential for energy savings. A minimum of 20 percent of the energy can be saved by using power electronics-based lighting drivers, and energy savings can be further increased using intelligent control solutions based on IoT. After the introduction of the first incandescent light bulb in 1879, the technologies for creating light sources have advanced a lot, with LED light being the most efficient and latest.
Power-electronic devices like TRIACS are used to develop dimmable drivers that have the ability to control both incandescent bulbs and LED lights to save costs. LED drivers based on PWM (pulse-width modulation) are used to achieve the ability to dim the light by precisely controlling the current output. The advancements in power electronics have now enabled LED driver ICs to be smaller than your fingertips. The ILD6150XUMA1 from Infineon Technologies is one such compact LED driver for high-power LEDs. It provides analog, PWM dimming control, and features adjustable over-temperature protection, as high-power LED generates a lot of heat.
Wide Band Gap-Based Power Electronics
Power electronics can be applied almost everywhere electric power is involved. Thus, selecting the right materials for semiconductor devices also plays a vital role. Over the last few decades, silicon (Si) has been the most preferred choice for developing these devices due to its low cost and wide range of voltage and current handling capacity. Meanwhile, with technology pushing more toward smaller sizes and higher efficiency, Si devices have reached their limits.
Comparison of Si, GaN, and SiC performance. (Image credit: reasearchgate.net)
SiC (silicon carbide) and GaN (gallium nitride) are emerging as promising technologies that offer a lot of advantages and can replace Si. GaN offers high-frequency switching capability and a bandgap of 3.2eV, while the bandgap in Si is only 1.1eV. SiC on the other hand features high-temperature and high-voltage capability along with higher bandgap when compared to Si. All these factors make SiC and GaN the future of semiconductors and are used for developing devices like MOSFETs. The GS065011 GaN transistor from GaN Systems is an example of one such device that benefits from the patented Island Technology cell layouts. It offers a very low thermal resistance of 150mΩ, thus enabling high-efficiency power switching for applications like LED drivers, battery charging, motor drives, etc.
Future Perspectives of Power-Electronics Equipment
There’s no doubt that humanity is now completely dependent on electricity to keep the world running. This creates an almost never-ending potential for research into power-electronic devices with higher performance and efficiency and getting electronic equipment to operate as close as possible to the ideal conditions. On the other hand, sustainability becomes one important aspect to keep in mind as materials like silicon and gallium are limited in the environment. As the performance increases, the demand for such converters will also increase, leading to the exploitation of raw materials. Thus, balancing both sides of increased energy savings by efficient energy will be a matter to look into in the future.
