As countries around the world tighten emissions standards, the demand for fully electric vehicles (EVs) is increasing. However, for EVs to see mainstream adoption, manufacturers must address the primary consumer concerns: longer driving ranges and faster charging. To address these concerns, EV manufacturers are beginning to redesign their vehicles to switch from the 400V battery systems widely used today to 800V battery systems, which can offer twice the voltage and 2.7 times the power density compared to a 400V system.
At Knowles Precision Devices, our expertise in capacitor technology helps developers working on some of the world’s most demanding applications across the medical device, military and aerospace, telecommunications, and automotive industries.
As the year comes to a close, it's the season to take some time to relax and reflect on the year. You’ve likely read many of our blog posts this year and you may have missed a few – it's been a busy year! Never fear, we've rounded up our most popular blog posts from 2019. We hope that they'll bring you some holiday cheer, or at least provide some ideas and insights to use for a successful 2020.
Today’s advancements in power electronics are reaching all-new highs in performance. In the quest for increasing efficiency and power density of converters and inverters, manufacturers are looking to use WBG semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), for making metal-oxide semiconductor field-effect transistors (MOSFETs), metal-semiconductor field-effect transistors (MESFETs) and other devices.
These materials are capable of operating at faster switching frequencies – and therefore greater current and power – compared to traditional silicon-based materials. Their higher temperature rating also allows the semiconductors to be used in harsher environments found in electric vehicles, aerospace, energy production, and test equipment.
Innovating essential high technology systems with demanding specifications is always challenging; making any sort of difference requires extensive resources and deep subject matter knowledge.
But that’s what keeps it interesting.
One of the primary goals in electric vehicles (EVs) is to increase the efficiency of its power conversion devices. The more efficiently power is converted, the further distance the EV can travel on one charge. For example, by reducing losses in a DC-to-DC (or DC/DC) converter, the converter (and overall vehicle) benefits from improved energy efficiency, a more streamlined design, and diminished heating from components.
In power electronics, rectification is the conversion of alternating current (AC) to direct current (DC). After the AC signal enters a rectifier circuit consisting of power diodes, the resulting raw rectified waveform yields a series of half sine waves with significant ripple. In order to minimize the pulsating DC voltage, a smoothing capacitor is placed in parallel with the load across the rectifier output. As the rectifier voltage rises, the capacitor charges and stores energy like a reservoir. Then when the rectifier voltage falls, the capacitor discharges, greatly reducing the ripple voltage.
Today, with the continued drive for more technical features in conventional cars and the increasing electrification of the drive train, the challenges facing electronics designers are ever increasing. Alongside a drive to lower costs and smaller form factors, MLCC’s are being used in ever harsher applications and in ever increasing numbers. This is driving board population density upwards and with it concerns for reliability and particularly the likelihood of mechanical cracking. Thus electronic designers are now demanding flexibility that exceeds the current Automotive Electronic Council bend test specification (AEC-Q200 Rev D June 1, 2010).
The advantages of multilayer ceramic (MLC) capacitors over plastic film types include their smaller physical size, lower inductance, and ability to operate at higher temperatures. These advantages make MLC capacitors very well suited to high power applications, such as power converter systems in electric (EV) and hybrid electric (HEV) vehicles.
The worldwide electric vehicle (EV) market is exploding in demand and mainstream adoption as governments push for fuel economy improvements and automotive companies look for new market opportunities. According to Forbes, “by 2020, EVs are likely to cost the same as conventional fuel powered equivalents.” Major manufacturers – like General Motors, Toyota, and BMW – plan to release “a mouthwatering potential of 400 models and estimated global sales of 25 million by 2025.” For EV design engineers and purchasing agents, this drive towards increased electrification results in the challenge of finding cutting-edge components that can handle increasing temperatures, voltage, and power without sacrificing reliability, availability, and footprint.