Vehicle-side charging circuit for a vehicle with electric drive, and method for operating a vehicle-side current converter, and use of at least one winding of a vehicle-side electric machine for intermediate storagectrical machine for buffer

A vehicle-side charging circuit for a vehicle with electric drive, the charging circuit comprising:

• an alternating current (AC) connector;
• a controlled rectifier connected to the AC connector;
• an electric machine including at least one winding, the electric machine includes a locking actuator, the locking actuator includes a locking bar which selectively arrests or releases a rotor of the electric machine in a controlled manner;
• a current converter connected to the electric machine, the at least one winding of the electric machine is coupled in series between the controlled rectifier and the current converter;
• an energy-storage-device connector;
• a control device connected in triggering manner to the current converter, the control device operates the current converter in a first state in an inverter mode, and in a second state in a charging mode, wherein:
• in the inverter mode, the control device triggers the current converter to transform a voltage applied to the energy-storage-device connector into a triggering signal with which the electric machine can be operated, and
• in the charging mode, the control device triggers the current converter to transform a voltage outputted by the controlled rectifier to the current converter via the at least one winding into a charging signal which can be output to the energy-storage-device connector for charging an energy-storage device coupled thereto;
• an electromagnetic compatibility (EMC) filter coupled between the controlled rectifier and the AC connector;
• a smoothing capacitor connected in parallel between the controlled rectifier and the electric machine;
• and
• a disconnecting switch connected in series between the controlled rectifier and the electric machine.

A method for operating a vehicle-side current converter coupled to an electric machine and an electrical energy-storage device, the method comprising:

• in an inverter mode:
• feeding the current converter from the energy-storage device,
• generating, at the current converter, a triggering signal causing the electric machine to operate;
• and
• in a charging mode:
• feeding the current converter via at least one series-connected winding of the electric machine from an external energy source via an AC circuit and via a controlled rectifier, and
• generating, at the current converter, a charging signal supplied to the electrical energy-storage device;
• forming a power transformer with the at least one winding of the electric machine and the current converter, in which the at least one winding operates as a storage inductor;
• wherein:
• in the charging mode, mechanically locking the electric machine by way of a locking bar, and
• in the inverter mode, failing to lock the electric machine by way of the locking bar.

A method for operating a vehicle-side current converter to which an electric machine and an electrical energy-storage device are coupled, wherein

• in an inverter mode:
• the current converter is fed from the energy-storage device and generates a triggering signal with which the electric machine is operated;
• and
• in a charging mode:
• the current converter is fed via at least one series-connected winding of the electric machine from an external energy source via an alternating current (AC) circuit and via a controlled rectifier and generates a charging signal which is supplied to the electrical energy-storage device, and
• the at least one winding of the electric machine together with the current converter form a power transformer in which the at least one winding operates as a storage inductor, the controlled rectifier is controlled in order to adjust an effective current or a voltage, the controlled rectifier is controlled to adjust an effective current or a voltage;
• wherein in the charging mode a locking bar of a locking actuator mechanically locks the electric machine, and in the inverter mode the locking bar does not lock the electric machine.