BACKGROUND

As battery technology has become more advanced, so have the use of batteries within electric vehicles (EV). In some instances, such as commuter vehicles, EVs aim to replace traditional gas-combustion vehicles as EVs offer a more environmental friendly solution. However, for EVs to eventually replace gas-combustion vehicles, EVs must be able to operate comparably and safely. One possible drawback of EVs is battery safety. Battery operations, such as charging and discharging processes, may be limited for battery safety. However, limiting batteries to avoid overcurrent or undercurrent may impact the available current for an EV, which in turn may affect operability of the EV. Hence, limiting batteries during charging and discharging events may be important for EVs. Therefore, there is a need for improved limiting and controlling of battery charge and discharge currents for batteries within EVs.

SUMMARY

Various embodiments are described related to a system for controlling a maximum current threshold of a battery system within a vehicle. The system for controlling a maximum current threshold for a battery system may include one or more vehicle systems, a battery module having one or more batteries, and a battery management system having a battery monitoring unit that monitors a current parameter of the battery module. The system for controlling a maximum current threshold may also include a battery control system, having one or more processors, that may receive the current parameter from the battery monitoring unit. The battery control system may be configured to identify a current event for the battery module, determine a duration of the current event, and compare the duration of the current event to a plurality of time thresholds. The battery control system may also be configured to determine the current parameter based on the duration of the current event, determine a maximum current parameter based on the duration of the current event and the current parameter, and control the one or more vehicle systems such that a current of the one or more batteries does not exceed the maximum current parameter. In embodiments, the battery control system may be further configured to compare the maximum current parameter to a previous maximum current, determine a current transition based on the maximum current parameter and the previous maximum current parameter, and control the one or more vehicle systems based on the current transition. For example, the battery control system may control the one or more vehicle systems such to vary the current of the one or more batteries based on the current transition.

Optionally, comparing the duration of the current event to the plurality of time thresholds may include comparing the duration of the current event to a short-pulse threshold and a long-pulse threshold to determine a first result. In some embodiments, the first result may indicate that the duration of the current event is less than the long-pulse threshold. Based on the first result the battery control system may be configured to calculate a current Root-Mean-Square (RMS)-value based on the current parameter, compare the current RMS-value to a long-pulse RMS-value to determine a second result, and determine based on the second result the maximum current parameter based on either a short-pulse parameter or a current transition between the short-pulse parameter and a long-pulse parameter. In other embodiments, the first result may indicate that the duration of the current event is greater than the long-pulse threshold. Based on the first result the battery control system may be configured to calculate a current RMS-value based on the current parameter, compare the current RMS-value to a long-pulse RMS-value and a continuous RMS-value to determine a third result, and determine based on the third result the maximum current parameter based on at least one of a short-pulse parameter, long-pulse parameter, or a continuous parameter.

A method for controlling current of a battery management system is also described herein. The method for controlling current of a battery management system may include identifying a current event for a battery module having one or more batteries, determining a duration of the current event, comparing the duration of the current event to a plurality of time thresholds, measuring a current parameter based on the duration of the current event, determining a maximum current parameter based on the duration of the current event and the current parameter, and controlling vehicle systems such that a current of the one or more batteries does not exceed the maximum current parameter. The method may also include comparing the maximum current parameter to a previous maximum current parameter and determining a current transition based on the maximum current parameter and the previous maximum current parameter. In embodiments, comparing the duration of the current event to the plurality of time thresholds may include comparing the duration of the current event to a short-pulse threshold and a long-pulse threshold to determine a first result. The first result may indicate that the duration of the current event is less than the short-pulse threshold. Based on the first result, the method for controlling current of the battery management system may determine the maximum current parameter based on a short-pulse parameter. Optionally, determining the maximum current parameter may be further based on one or more condition factors including a temperature and a state-of-charge for each of the one or more batteries.

In some embodiments, the first result may indicate that the duration of the current event is less than the long-pulse threshold. In such embodiments, based on the first result the method may include calculating a current Root-Mean-Square (RMS)-value based on the current parameter, comparing the current RMS-value to a long-pulse RMS-value to determine a second result, and determining based on the second result the maximum current parameter based on either a short-pulse parameter or a current transition between the short-pulse parameter and a long-pulse parameter. In other embodiments, the first result may indicate that the duration of the current event is greater than the long-pulse threshold. In such embodiments, based on the first result the method may include calculating a current RMS-value based on the current parameter, comparing the current RMS-value to a long-pulse RMS-value and a continuous RMS-value, and determining a third result. The third result may indicate that the current RMS-value is greater than the continuous RMS-value. In some embodiments, based on the third result the method may include determining the maximum current parameter based on a continuous parameter. In other embodiments, the third result may indicate that the current RMS-value is greater than the long-pulse RMS-value. In such embodiments, based on the third result the method may include determining the maximum current parameter based on a long-pulse parameter. While in still other embodiments, the third result may indicate that the current RMS-value is less than the long-pulse RMS-value. In such embodiments, based on the third result, the method may include determining the maximum current parameter based on a short-pulse parameter.

A non-transitory processor-readable medium for determining a maximum current parameter for a battery module including processor-readable instructions is also described herein. The processor-readable instructions may be configured to cause one or more processors to identify a current event for a battery module including one or more batteries, determine a duration of the current event, compare the duration of the current event to a plurality of time thresholds, determine the current parameter based on the duration of the current event, determine a maximum current parameter based on the duration of the current event and the current parameter, and control one or more vehicle systems such that a current of the one or more batteries does not exceed the maximum current parameter. In some embodiments, the maximum current parameter may be determined based on at least one of a short-pulse parameter, a long-pulse parameter, or a continuous parameter. In other embodiments, the processor-readable instructions may be further configured to cause the one or more processors to compare the maximum current parameter to a previous maximum current parameter, determine a current transition based on the maximum current parameter and the previous maximum current parameter, and control the one or more vehicle systems such to vary the current of the one or more batteries based on the current transition.

