Abstract: A method is provided for monitoring a state of health of a vehicle system and includes measuring a plurality of parameter values for the system at different running conditions as an end of line test, storing the parameter values in a fingerprint file, measuring the same plurality of parameter values that is comprised in the fingerprint file after a predefined time interval, adding a predefined ageing offset to the fingerprint file, where the ageing offset corresponds to a predicted wear of the system during the predefined time interval, thereby obtaining a time modified fingerprint file for the system, comparing the measured values with the time modified fingerprint file, and issuing a message if the measured values deviates from the time modified fingerprint file. The state of health can be compared with initial measurements such that the state of health of a vehicle system or component can be monitored over a longer time period.

Abstract: A traction voltage system in a vehicle includes a junction box with multiple connectors for electrical components, which components include electrical supplies and electrical loads, and an electronic control unit arranged to monitor current flowing flow to or from the components. A controller or a circuit breaker is arranged to control the supply of power to each respective component, and at least all but one of the connectors are provided with a current sensor arranged to transmit a signal representing detected current values to the electronic control unit. The electronic control unit is arranged to determine an instantaneous current value flowing to or from each component, to compare the instantaneous current value with a predetermined limit value for each connector, and to take action in response to the comparison. A method for controlling the traction voltage system is also provided.

Abstract: A method is provided for balancing an energy storage system that includes a plurality of connected battery cells in a vehicle including an electric machine arranged for propulsion of the vehicle. The method includes monitoring a need for balancing of the cells, initiating a request for the balancing based on the operational condition related to the battery cells, discharging or charging the energy storage system until the state of charge of the energy storage system has reached a predetermined level, and balancing the voltage of the battery cells. The method further includes allowing input instructions representing a time schedule for the balancing upon initiating the request for balancing, and initiating the discharging so that the energy storage system reaches the predetermined level of the state of charge in accordance with the input instructions. An arrangement for balancing an energy storage system is also provided.

Abstract: A method for estimation of state-of-health (SOH) characteristics of a battery in hybrid vehicles includes charging and discharging the battery at least one time within an upper region of a state-of-charge (SOC) window, wherein the battery; charging and discharging the battery at least one time within a lower region of the SOC window, calibrating a battery management unit included in the hybrid vehicle by using the reached levels outside the SOC window and estimating the SOH characteristics of the battery during the charge and discharge periods by using the battery management unit.

Abstract: A method is provided for monitoring a state of health of a vehicle system and includes measuring a plurality of parameter values for the system at different running conditions as an end of line test, storing the parameter values in a fingerprint file, measuring the same plurality of parameter values that is comprised in the fingerprint file after a predefined time interval, adding a predefined, ageing offset to the fingerprint file, where the ageing offset corresponds to a predicted wear of the system during the predefined time interval, thereby obtaining a time modified fingerprint file for the system, comparing the measured values with the time modified fingerprint file, and issuing a message if the measured values deviates from the time modified fingerprint file. The state of health can be compared with initial measurements such that the state of health of a vehicle system or component can be monitored over a longer time period.

Abstract: A method is provided for operating a hybrid electric vehicle including an internal combustion engine and an electrical system, which electrical system includes at least one electronic control unit, an engine-driven electric machine (operable as a motor for driving the vehicle or as a generator for supplying power to one or more electrical loads via a high voltage traction bus, and a high voltage battery pack coupled to the high voltage traction bus by at least one contactor arranged to connect the battery pack to the high voltage traction bus. If it is determined that the at least one parameter indicates a condition preventing the battery pack from being connected to the high voltage bus, the electric machine is operated in voltage control mode during operation of the vehicle until the condition is eliminated, whereafter the high voltage bus is pre-charged and the high voltage battery pack reconnected.

Abstract: A method is provided for balancing the voltage of multiple series-connected electrochemical cells of an electrical storage system of a hybrid electric vehicle. The method includes discharging the electrical storage system by operating at least one large electrical machine of the vehicle at vehicle standstill until the state of charge of the electrical storage system or the cell having the lowest state of charge has reached a predetermined level, and subsequently balancing the voltage of the cells.