Bosch is expanding their semiconductor business with silicon carbide (SiC) chips produced at TSI Semiconductors of Roseville, California – an established chip producer producing large volumes on 200mm wafers for mobility, telecom and energy applications.
SiC chips are increasingly being employed in electric vehicles to increase range and enable more effective recharging, according to Bosch. Their use has witnessed dramatic growth.
Power semiconductors for electric vehicles
Power semiconductors for electric vehicles (EVs) provide greater efficiency by optimizing power conversion and distribution, leading to extended driving range and decreased energy usage. Furthermore, these semiconductors can adapt power delivery in order to improve performance and safety under variable driving conditions.
This shift is fuelling an increase in demand for semiconductor solutions that meet automotive-grade reliability and safety standards, while at the same time driving increased focus on developing battery management systems using advanced semiconductor technologies to enhance battery performance and longevity.
Furthermore, the semiconductor industry is adopting materials and devices with higher power density and better thermal management to help EVs meet rising consumer demands for greater performance, convenience, and connectivity features. These advances will assist EVs meet these growing consumer expectations more easily.
Silicon Carbide (SiC) is a promising semiconductor material used to increase power density in electric vehicle (EV) applications. SiC’s resistance to voltage surges caused by regenerative braking and fast charging can reduce premature failures of power electronics and allow faster transition times, further extend battery life, as well as chemical inertness that resist corrosion/oxidation.
Bosch recently invested over 1.5 billion dollars to acquire and upgrade their facility in Roseville, California to manufacture SiC chips – semiconductors found in traction inverters, onboard chargers and DC-DC converters for electric vehicles (EV).
Inverters for electric vehicles
Modern electric vehicles operate at high voltages, requiring sophisticated power systems to manage the energy flow. Power inverters serve as the heart of these power systems and must adhere to stringent safety requirements while keeping pace with motor dynamics.
Bosch silicon carbide (SiC) MOSFETs and IGBTs are integral parts of electric vehicle (EV) inverters that reduce complexity, improve current quality and allow faster charging. Furthermore, their superior thermal management allows them to provide higher efficiency driving range for their end user customers.
Inverters are key components of an electric vehicle (EV), providing consumers with a long-range EV experience and alleviating concerns such as range anxiety. Their design can vary depending on whether the car is full EV, hybrid, or commercial grade such as construction trucks or even motorsport-use EVs.
Commercial vehicle inverters should be designed to withstand short periods of back-EMF without needing backup power supplies, while electric motorsport inverters must be capable of reducing speed to reach a safe level of back-EMF. Furthermore, both types of inverters must also accommodate for high levels of switching rates, which requires complex circuitry to minimize electronic noise and mitigate electromagnetic interference (EMI). They may even include features like integrated fault protection that allows systems to detect and diagnose any failures that arise in operation.
On-board chargers for electric vehicles
An onboard charger (OBC) is an essential component in electric vehicles. It recharges the high-voltage battery pack from AC grids while the vehicle is parked, providing efficient charging with reduced charging times and built-in safety features.
OBCs consist of three primary components: PFC stage, DC-DC converter and BMS. The PFC stage transforms alternating current into direct current for conversion by the DC-DC converter to produce battery voltage; BMS monitors its battery output voltage within safe limits and ensures its output does not fluctuate excessively.
Onboard chargers for electric vehicles (EVs) come in two varieties – single or three phase. Single phase OBCs offer up to 11kW charging capacity and are ideal for residential environments. Three-phase OBCs have the ability to reach 22KW charging and offer faster charging speed – both types feature various communication protocols to ensure safe and efficient charging operations.
Bosch is making substantial investments in silicon carbide (SiC) production to support electric vehicles (EVs). Their move to acquire US chipmaker TSI Semiconductors shows their intent of creating an unreliable supply chain of SiC.
Bosch believes SiC power semiconductors will play a decisive role in electric vehicle onboard charging and DC-DC conversion, offering significant cost-cutting potential over conventional silicon devices. Their silicon carbide chips are smaller, cheaper and more energy efficient. Plus they can fit on 200-millimeter wafers allowing a shorter ramp-up period in Roseville with lower production errors and cost-cutting benefits.
Battery management systems for electric vehicles
Battery Management Systems or BMSs play a pivotal role in electric vehicles’ safety and performance, monitoring temperature to prevent overheating that could reduce battery lifespan or cause thermal runaway. They can also ensure optimal operating temperatures by employing cooling/heating systems as necessary; as well as optimizing charging cycles and cell balancing to increase durability.
BMSs for automotive OEMs come in various forms; each offers different advantages to automotive OEMs. A centralized BMS has one controller managing all battery cells within a battery pack, making implementation easy but vulnerable to component failure. By contrast, distributed BMSs utilize multiple controllers to manage individual batteries and modules individually and reduce wiring complexity while also decreasing error rates and improving reliability and performance.
Bosch stands as an industry-leader in silicon carbide power devices and can offer more advanced technologies for electric vehicles. Kroeger believes SiC chips will play a pivotal role in power electronics for these vehicles, particularly charging and DC-DC conversion, where efficiency gains can exceed 50 percent when compared with pure silicon alternatives; such gains allow drivers to extend one charge up to 6 percent longer per charge of their vehicle, according to Kroeger.
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