To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor. For this purpose, a controller 50 sets a target relief pressure of a relief valve 3 to a normal relief pressure Pn (first relief pressure) when an operation lever device 44 is not being operated and a storage amount SOC(t) of a battery 62 (the state quantity of an electric power source) is equal to or larger than a threshold S1, and sets the target relief pressure to a reduced relief pressure Pr(t) (second relief pressure) lower than the normal relief pressure Pn (first relief pressure) when the operation lever device 44 is not being operated, and the storage amount SOC(t) of the battery 62 (the state quantity of the electric power source) is smaller than the threshold S1.

To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor. For this purpose, a controller 50 sets a target relief pressure of a relief valve 3 to a normal relief pressure Pn (first relief pressure) when an operation lever device 44 is not being operated and a storage amount SOC(t) of a battery 62 (the state quantity of an electric power source) is equal to or larger than a threshold S1, and sets the target relief pressure to a reduced relief pressure Pr(t) (second relief pressure) lower than the normal relief pressure Pn (first relief pressure) when the operation lever device 44 is not being operated, and the storage amount SOC(t) of the battery 62 (the state quantity of the electric power source) is smaller than the threshold S1.

Embodiments of the present invention provide An electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means to receive a speed signal indicative of a speed of the vehicle, processing means arranged to determine a coupling state of the electric machine to the at least one wheel of the axle in dependence on the speed signal, and output means arranged to output a coupling signal indicative of the coupling state to control coupling of the electric machine to the at least one wheel of the axle.

A battery device in one aspect of the present disclosure comprises a battery, a cell voltage monitoring part, a power supply line, a plurality of monitor lines, and an interrupter. The interrupter interrupts the power supply line and all of the plurality of monitor lines when the battery enters an overdischarge state.

The figures illustrate an apparatus (10-1, 10-2, 10-3) for a vehicle (100) comprising: first energy storage means (12) for storing electrical energy; second energy storage means (14) for storing electrical energy; and control means (16) arranged to transfer electrical energy from the second energy storage means (14) to the first energy storage means (12) when the level of electrical energy stored in the first energy storage means (12) is below a first electrical energy threshold level and the level of electrical energy stored in the second energy storage means (14) is above a second electrical energy threshold level.

The figures illustrate an apparatus (10-1, 10-2, 10-3) for a vehicle (100) comprising: first energy storage means (12) for storing electrical energy; second energy storage means (14) for storing electrical energy; and control means (16) arranged to transfer electrical energy from the second energy storage means (14) to the first energy storage means (12) when the level of electrical energy stored in the first energy storage means (12) is below a first electrical energy threshold level and the level of electrical energy stored in the second energy storage means (14) is above a second electrical energy threshold level.

An overall loss L during non-execution of intermittent boosting (in ordinary boosting) is calculated from losses L1 and L2 of motors and a loss LC of a boost converter during non-execution of intermittent boosting. The overall loss L during execution of intermittent boosting is calculated from the losses L1 and L2 of the motors and the loss LC of the boost converter during execution of intermittent boosting. A minimum loss-time boosting voltage Vtmp at which the overall loss L provides a minimum loss Ltmp is set to a target voltage VH*. The boost converter is then controlled in a control state corresponding to the minimum loss-time boosting voltage Vtmp.

This control device for an electric vehicle is provided with: a discharge control unit which, when the electric vehicle has been turned off, if the SOC of the battery is within a prescribed range in which the battery is prone to deteriorate, performs control for discharging the battery until the SOC has left the prescribed range; a travelable distance calculation unit which calculates the travelable distance of the electric vehicle using the SOC and a travel coefficient; and a travel coefficient correction unit which, before and after performing control for discharging the battery is performed by the discharge control unit, corrects the travel coefficient such that the travelable distance calculated by the travelable distance calculation unit is reduced.

This control device for an electric vehicle is provided with: a discharge control unit which, when the electric vehicle has been turned off, if the SOC of the battery is within a prescribed range in which the battery is prone to deteriorate, performs control for discharging the battery until the SOC has left the prescribed range; a travelable distance calculation unit which calculates the travelable distance of the electric vehicle using the SOC and a travel coefficient; and a travel coefficient correction unit which, before and after performing control for discharging the battery is performed by the discharge control unit, corrects the travel coefficient such that the travelable distance calculated by the travelable distance calculation unit is reduced.

An over-discharge diagnosing method includes, among other things, evaluating concurrently, a voltage behavior of a battery pack, a current behavior of the battery pack, and a temperature behavior of the battery pack. The method further includes detecting an over-discharge based on the evaluating, and communicating an over-discharge notification in response to the detecting.