International Rectifier’s Evaira Advanced Energy Management System (EMS) is designed to dramatically extend battery life in electric vehicles and Hybrid Electric Vehicles. Evaira EMS is International Rectifier’s advanced-algorithm Energy Management System for heavy duty battery applications. This solution easily scales to both high cell-count battery packs and high current applications, enhancing battery pack performance and extending battery pack service life for electric and hybrid electric platforms in both automotive and heavy industrial market sectors.

EMS for Extending Battery Life in Electric VehiclesThe performance of a multi-cell battery pack is limited by the differences between the weakest and strongest cells in the pack. IR’s Evaira advanced energy management system (EMS) utilizes rapid bypass equalization ensuring all cells age uniformly by balancing the state of charge (SOC) of all of the cells within a battery system, resulting in a dramatic extension of battery life and significantly improving battery performance. The complete battery management system also features advanced algorithms, balancing, charge and discharge management and shutoff for electric vehicle applications for the automotive, commercial and military segments.

Designed to maximize convenience for the system integrator, Evaira EMS’s telematic features support remote statistics, including real-time pack voltage, current, ambient temperature, state-of-charge (SOC), state-of-health (SOH), amps expended, and operating time through its integrated external interfaces. The unit has isolated digital I/O expansion lines available for custom applications. These can be used to drive indicators, turn on or off chargers, remote fans, etc. Communications interfaces are also robust, being tolerant to EMI generated in high-current and high-voltage applications.

Evaira EMS monitors the characteristics of each individual cell while the battery is in operation (discharge mode) and dynamically adjusts its relative loading to match its capacity using a process called Rapid-Bypass. Advanced algorithms are employed, performing SOC calculations based on voltage levels, discharge rates, coulomb counting, and pack SOH, which are compensated for temperature passed through Kalman filters. This capability gives the battery pack designer control to make trade-offs between pack capacity, service life, discharge time, and cost parameters.

Uniform aging of the cells within a battery pack, achieved through Evaira EMS’s wear-leveling algorithms, significantly extends the service life of high cell-count battery packs.

Features and Benefits of Evaira Energy Management System (EMS)

  • Discharge and charge monitoring and cutoff
  • Supports systems up to 700V with unlimited number of modules
  • Real-time state-of-charge calculation
  • Statistical logging using non-volatile memory
  • SAE J1772 control pilot, proximity detection, HV isolation detection circuitry
  • CANbus 2.0b, Ethernet and RS232 communication interfaces
  • Real-time continuous analysis of cell SOH
  • Rapid-bypass leveling techniques are used to actively balance cells
  • Pack wear-levelling extends pack operating life
  • Robust, EMI resistant system communication