Vehicle Electrification means special requirements for the passive components involved: Besides AEC-Q200, PPAP, IATF certification, the items need to have high reliability and endurance. Finally, any solution must be cost optimized and a second source in the market should be available.
The On-Board charger system converts the AC input from the power grid to a DC input for the battery. It is housed in an aluminum case to meet security standards and for safety from dirt, humidity or salt spray. The minimum requirements are typically temperature ranges from -40°C to + 85°C.
The typical Block Diagram of an OBC has 4 main steps:
• Electro Magnetic Interference (EMI) Filter
• Power Factor Correction (PFC) stage
• Resonant Stage
• Output filter
The Electro Magnetic Interference (EMI) Stage
The EMI Filter, also called EMI suppression filter, catches noise coming over the mains supply and protects against the harmful impacts of electromagnetic interference. These filters extract any unwanted current conducted through wiring or cables, while allowing desirable currents to flow freely. EMI filters that suppress noise from grid power are also called EMI power line filters. EMI filters contain X and Y Capacitors as well as Common Mode Chokes.
YAEGO offers several certified solutions like R52 or R47-V057 series as X Capacitors and R41T or SMP253 series as Y capacitors. Depending on the series, the maximum temperature is 100°C or more.
Common Mode chokes in EMI Filters must carry high currents of 35A or much more, depending on the technology. Typically, MnZn Coil Inductors are used here. Due to the high temperature range of 150°C for YAGEO Common Mode Choke SC series, they can carry high currents by having low losses. Depending on customer’s requirements, either a horizontal or low-profile version or a vertical version that consumes less board space are available.
The Power Factor Correction (PFC) stage
The PFC stage covers Power differences due to the frequency shift. It also includes a DC Link Capacitor for stabilizing the Output PFC DC voltage. This stage can be separated into two main functions: the PFC stage itself followed by a DC Link capacitor.
The PFC stage includes a current sensing function, which can be solved with Current sensing Resistors or Shunts. YAGEO Shunt Series (PE, PA or PU) offer a wide range in case size and resistance with power up to 36W. Due to its construction an operating temperature of 275°C is possible for some series. The High-Power PFC Inductor is the most important part of the PFC stage. YAGEO offers a high variety of Inductors from Pulse Electronics. Also, Capacitors are needed in the PFC stage. To meet the frequency requirements of the Wide Band Gap technology, Ceramic capacitors can be a perfect solution to cover the needs.
The DC Link capacitor is the other important part. Three different capacitor technologies can be chosen: Aluminum Electrolytic, Film or Ceramic.
Aluminum Electrolytic Capacitors offer a wide product range up to 1000µF and usable for high ripple currents. YAGEO ALA series is a Snap-In THT product with high vibration proof up to 20G and a long lifetime of 10.000 hours and more at maximum temperature. As rectangular version, YAGEO offers first-to-market ALR series with ideal volumetric efficiency and up to 40G vibration capability.
DC Link Film Capacitor C4Ax THT series are also available in a wide range up to 210µF and with high temperature products of 125°C or if needed up to 135°C. YAGEO offers products especially designed for harsh environments offering high ripple currents and a high voltage range higher than 1000V.
In SMT technology also Ceramic Capacitors can be chosen as DC Link capacitor. Either a capacitor bank of multiple MLCC or single chips such as the KC-Link series, the first-to-market Class 1 MLCC for currents up to 15A can be chosen. Especially for high temperatures or high frequency applications, this series is the best solution. In case of board space saving requirement, YAGEO offer the unique KONNEKT technology to combine maximum 4 MLCC to a stacked capacitor with a Transient Liquid Phase Sintering Process. Using this technology wills save 75% board space and pick-and-place time.
The Resonant Stage
The Resonant Stage is an LLC resonant filter including galvanic isolation if needed. As Snubber Capacitor typically one or more Ceramic Capacitors in parallel and/or series connection can be used. YAGEO Film Capacitor series R75 or R76 reach high capacitance values up to 33µF, voltages up to 2000V and temperature ranges up to 125°C.
The Output Filter
Finally, the output filter stage to the internal power supply of the car filters the output of the full OBC system. Typically, a Differential Mode Filter Inductor is used. As output capacitors, a DC Link Film Capacitor or any Ceramic Capacitor series can be chosen.
As a conclusion, On-Board Charging Systems require passive components that have high reliability, are designed for harsh environment and that are mission critical IATF components. The YAGEO Group portfolio offers more than 20 different product series suitable in an On-Board Charger that are right up to this job.
