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.
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.
Join us and Charged EVs on Wednesday, November 17 at 10 am EDT for our latest live webinar – Addressing MLCC Performance Issues in High-Voltage EV Applications.
Achieving high capacitance means going big. But how do you do that while still maximizing board space? At Knowles Precision Devices, we’ve developed a new method for building customizable large capacitor assemblies that capitalize on the vertical space above the circuit board. While stacked capacitor assemblies have been around for many years, these parts do not have very good bump and vibration withstand due to the thin leads used in their construction. These new assemblies from Knowles Precision Devices offer a ruggedized construction capable of withstanding high levels of shock and vibration. This offers a unique combination of capability, durability, high capacitance, and very high voltage in a smaller area, making these capacitors ideal for automotive, military, and aerospace applications.
According to the U.S. Bureau of Transportation Statistics, 2020 was the fifth consecutive year of growth in electric vehicle (EV) sales, and the demand is growing. Based on the first quarter numbers, the Bureau anticipates 2021 sales are on a path to surpass last year’s.
Join Knowles Precision Devices and many members of the advanced battery and EV/HEV community from May 18 – 20 at this year’s virtual edition of The Battery Show Europe. Since this year’s show has been designed to virtually recreate the tradeshow experience from the comfort and safety of your own home or office, we will be exhibiting a variety of our advanced battery technology at virtual booth 8-351.
In electric vehicle (EV) applications, filter capacitors are a special type of component commonly used as input and output capacitors. Also known as noise suppression or electromagnetic interference (EMI) filters, these particular capacitors act to remove noise and other unwanted signals on the line. On the high voltage alternating current (AC) side of a system, the capacitors often provide EMI filtering, whereas on the direct current (DC) side of a subsystem, they serve to smooth ripple components of the AC and filter out noise.
With production of high-performance electric vehicles (EVs) such as the Porsche Taycan and several manufacturers slated to release EVs with 800 V battery systems in 2021, using high-voltage battery systems in EVs is no longer just theoretical. Since vehicles operating at higher voltages can address consumer’s main concerns with EVs, this is a welcome advancement, especially as some countries are announcing regulations to eventually allow only EV sales. These changes include accelerating charging time by increasing power and reducing the weight of vehicles which, among other improvements, helps increase driving range and reduce consumer range anxiety.
In our last article about electric vehicles (EV), we talked about using DC link capacitors as an intermediary buffer in power converters. Today’s topic covers another useful power module component – the snubber capacitor. Snubbers are energy-absorbing circuits used to protect electronics from voltage spikes and transients caused by turning a switch from the On to Off state. Opening a switch intrinsically induces a high voltage across the device, and the snubber provides an alternate flow path for the excess energy to be absorbed by the snubber capacitor and dissipated by a resister or other load.
As a fundamental component of circuit design, equivalent series resistance (ESR) is the measurement of all the non-ideal electrical resistances in series with a capacitor. When current flows through a multilayer ceramic capacitor (MLCC) due to application of alternating voltage, heat is generated in the MLCC due to the losses, specifically ESR. As a result, this self-heating can cause various performance and reliability issues in the circuits of today’s more complex and smaller electronic systems.