High Voltage Battery Management System (BMS)
High voltage batteries are batteries with many sets of parallel cells in series stacked to produce a battery pack with voltages reaching up to 1000V. The most typical applications where high voltage batteries are used are:
- Battery electric vehicles (BEVs)
- Plug in hybrid electric vehicles (PHEVs)
- Full hybrid electric vehicles (FHEVs)
- Commercial electric vehicles (CAVs)
- Energy Storage Systems
To ensure the optimal use of the energy, to manage the charging and discharging processes, and to assess each cell‘s State-of-Charge(SoC), State-of-Health (SoH), and other status parameters, the battery management system (BMS) monitor and controls all processes relevant to the battery’s overall performance and lifetime.
Infineon offers a set of cell balancing and monitoring solutions tailored to high voltage batteries with high functional safety requirements. Additionally, the cell balancing and monitoring devices are accompanied by isolated communication transceivers to protect the pack from losing its isolation and facilitate robust communication between the CMB devices and the master controller. Learn more about our CMB and isolated communication devices.
Current sensing in BMS is used to accurately predict the State of Charge (SoC). That is because of the highly flat nature and sensitivity of the SoC curve to the cell state (e.g. voltage, temperature, age, etc.) As such deducing the SoC accurately from the cell voltage alone would not be possible. Therefore, a current sensor is used for predicting the SoC using Coulomb counting, by measuring the charges that enter or leave a battery cell. Learn more about Infineon's current sensing solutions.
The higher the series cell count of a battery pack the more the CMB devices are required to be stacked. This means that CMB devices might need to be isolated, especially in High Voltage BMSs where the battery pack needs to be isolated at all time and the master controller is connected to the 12V domain. To resolve the isolation issue, Infineon offers wired and wireless isolated communication solutions:
- Wired isolation: Infineon offers a robust automotive-grade isolated UART transceiver TLE9015DQU with exceptional robustness for inductive and capacitive isolations. Learn more about Infineon's wired BMS solutions.
- Wireless isolation: Infineon offers robust automotive-grade Bluetooth devices that support connected mesh topologies CYW89820. The CYW89820 is a monolithic, single-chip, Bluetooth 5.0 compliant, standalone baseband processor SoC with an integrated 2.4 GHz transceiver for wireless connectivity across battery modules. Learn more about wireless connectivity solutions for Industry, IoT, and Automotive. Learn more about Infineon's wireless BMS solutions.
Lithium-ion batteries are sensitive to being operated outside their safe operating area (SOA) such as over/under-charging, over/under-heating, etc. As such disconnecting the battery once operated outside its SOA would be necessary. Infineon offers a set of products and solutions for disconnecting the battery such as:
- Automotive smart switches for driving the mechanical relays
- Automotive high voltage MOSFETs and drivers for solid-state disconnects
Learn more about our disconnection solutions.
Besides current, voltage and temperature measurements advanced analytics are performed on pack-level with respect to thermal, electrical and mechanical strain:
- Highly accurate pressure sensors allows an early detection of thermal runaway events or unauthorized pack manipulations e.g. for modification or replacement of cells by measuring variations in pressure.
- Gas sensors can be used to sense evaporated CO2 from the cell’s electrolyte as a result of cell aging or overstress could be a vital indicator for battery health.
FRAM: ExcelonTM F-RAM™, like any other nonvolatile memory technology, is subject to physical degradation that can eventually lead to device failure if not addressed appropriately. F-RAM write/read endurance and data retention are the two end-of-life (EoL) parameters to specify its reliability and performance in a system. Learn more about the F-RAM data retention performance at various operating temperatures and find a method and guidance to accurately calculate the system’s EoL based on its operating temperature profile. Check the application note.
Infineon offers instantly non-volatile Excelon F-RAM with the lowest power operating at 20, 50, or 106MHz, capacity from 2Mb to 8 Mb. Read/write performance 4kb/s to 4 Mb/s using serial SPI / I2C or 64 kb/s to 4Mb/s for 8-/16-bit parallel access. Excelon F-RAM provides an endurance of 1e14 cycles and 100 years of data retention. It is radiation tolerant and has a low SER. The combination of high endurance, long data retention, and fast access makes it a perfect fit for non-volatile data logging.
Semper Flash: The Semper NOR Flash Memory Family is Infineon's newest high-performance, safe, and reliable NOR Flash memory solution that integrates critical safety features for automotive and industrial systems. With Semper NOR Flash Memory, Infineon introduces the industry's first ASIL-B compliant and ASIL-D-ready NOR Flash memory.
Semper Secure Flash: Semper Secure NOR Flash delivers security, safety, and reliability to automotive and industrial systems at a low total-cost-of-ownership. This advanced, secured, and easy-to-use NOR Flash device protects code and data from hackers with unparalleled system integrity. It is built on the proven Semper NOR Flash family, combines advanced security with industry-leading functional safety and reliability, and is engineered to last a lifetime.
Learn more about our memory and event logging solutions.