Methods and systems for operating a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, various vehicle operating modes may be entered from a baseline vehicle operating mode and the vehicle operating modes may revert back to the baseline vehicle operating mode in a plurality of stages so that returning to the baseline operating mode may be less noticeable to vehicle occupants.

A hybrid electric vehicle having a controllable switch that enables a DC link to be operated independent from an energy storage system (ESS) is provided. The ESS is selectively couplable to the DC link via the controllable switch. A processor is configured to control the switch to open and close under certain conditions. When the switch is opened, the processor is configured to instruct an engine controller to cause an engine which is coupled to a generator to boost engine output. The generator is coupled to a generator inverter which is also coupled to the DC link. A motor inverter is also coupled to the DC link and is configured to provide AC power to the motor.

A hybrid electric vehicle having a controllable switch that enables a DC link to be operated independent from an energy storage system (ESS) is provided. The ESS is selectively couplable to the DC link via the controllable switch. A processor is configured to control the switch to open and close under certain conditions. When the switch is opened, the processor is configured to instruct an engine controller to cause an engine which is coupled to a generator to boost engine output. The generator is coupled to a generator inverter which is also coupled to the DC link. A motor inverter is also coupled to the DC link and is configured to provide AC power to the motor.

A DCDC output voltage control method and control system for a hybrid electric vehicle are provided. The method includes: when a DCDC converter is in a buck operation mode, determining whether the vehicle is in a high power output demand state or an abnormal engine flame-out state; if so, setting the output voltage of the DCDC converter to a normal target voltage; otherwise, determining whether a low-voltage load has a charging voltage boost demand, and when the low-voltage load has the charging voltage boost demand and the power of a high-voltage battery is greater than a power threshold, setting the output voltage of the DCDC converter according to the voltage level corresponding to the charging voltage boost demand, to meet the charging demand of the low-voltage load. The fuel economy of a hybrid power assembly system can be optimized.

Methods and systems for operating a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, various vehicle operating modes may be entered from a baseline vehicle operating mode and the vehicle operating modes may revert back to the baseline vehicle operating mode in a plurality of stages so that returning to the baseline operating mode may be less noticeable to vehicle occupants.

A system control unit for controlling a charging system that is intended for charging an electrical energy storage device, comprising an electric generator; an internal combustion engine that is mechanically connected with the electric generator; a generator controller for controlling the electric generator; an engine controller for controlling the internal combustion engine; and a transmitting device for transmission of messages, whereby the engine controller is connected with the generator controller by way of the transmitting device, and whereby the engine controller is operable in that a message containing information about an operating state of the internal combustion engine can be produced and said message can be sent to the generator controller via the transmitting device.

A direct injection injector injects all of fuel having an idle required fuel amount required for an idle operation and makes a port injection injector inject no fuel from a second time to a third time so that an internal combustion engine executes idle operation from second time to third time. A fuel cut operation in which the fuel is not injected from both the direct injection injector and the port injection injector is executed from third time so that operation of the internal combustion engine is stopped at or after third time. At least one of the direct injection injector and the port injection injector inject the fuel so that operation of the internal combustion engine is restarted when a predetermined engine restart condition is satisfied under a state where operation of the internal combustion engine is stopped at or after third time.

The invention relates to an arrangement for supplying a rail vehicle with electrical energy. One electrical machine is allocated to each of at least two internal combustion engines for generating electrical energy. A common controller is designed to start the internal combustion engines individually as required. At least one pre-heating device is designed to pre-heat the internal combustion engines before a start. A temperature detection device is thermally coupled to the internal combustion engines. The controller is designed, during an operation of one of the internal combustion engines, to start another of the internal combustion engines if, due to cooling of the other internal combustion engine, a temperature of the other internal combustion engine detected by a temperature identifying device reaches or exceeds a temperature threshold.

A DCDC output voltage control method and control system for a hybrid electric vehicle are provided. The method includes: when a DCDC converter is in a buck operation mode, determining whether the vehicle is in a high power output demand state or an abnormal engine flame-out state; if so, setting the output voltage of the DCDC converter to a normal target voltage; otherwise, determining whether a low-voltage load has a charging voltage boost demand, and when the low-voltage load has the charging voltage boost demand and the power of a high-voltage battery is greater than a power threshold, setting the output voltage of the DCDC converter according to the voltage level corresponding to the charging voltage boost demand, to meet the charging demand of the low-voltage load. The fuel economy of a hybrid power assembly system can be optimized.