System and method for charging electric vehicles
The present teaching relates to method and system for charging a rechargeable battery deployed in an electric apparatus. The system resides in the electric apparatus. The system comprises a motor, an inverter, an output rectifier, a configurator, and a controller. The motor comprises a stator having a plurality of stator teeth and a plurality of stator windings wounded on the plurality of stator teeth. The inverter comprises a plurality of power switch devices. The configurator comprises a plurality of contactors coupled with the plurality of stator windings and the plurality of power switch devices. The controller controls the plurality of power switch devices and the plurality of contactors, so as to configure the system to operate in one of a traction mode and a charging mode.
1. A reconfigurable traction-charging system residing in an electric apparatus having a rechargeable battery, comprising:
a motor comprising a stator having a plurality of stator teeth and a plurality of stator windings wounded on the plurality of stator teeth, wherein a stator winding on at least one stator tooth of the motor is split into two or more coils;
an inverter comprising a plurality of power switch devices;
an output rectifier;
a configurator comprising a plurality of contactors coupled with the plurality of stator windings and the plurality of power switch devices; and
a controller for controlling the plurality of power switch devices and the plurality of contactors, so as to configure the reconfigurable traction-charging system to operate in one of a traction mode and a charging mode,
wherein:
under the traction mode, the rechargeable battery supplies electric energy to the motor via the inverter; and
under the charging mode, connections associated with the plurality of power switch devices and the stator windings are configured by the configurator to form a charger that draws electric energy from an external power supply to charge the rechargeable battery, and wherein
a stator winding on at least one stator tooth of the motor is split into two or more coils;
under the charging mode, the two or more coils and the corresponding at least one stator tooth form a transformer in the charger; and
under the traction mode, the two or more coils are connected in parallel or in series to form a phase winding.
2. The reconfigurable traction-charging system of claim 1 , wherein
the external power supply is a multiple phase power supply;
the system further comprises an input bridge rectifier; and
the input bridge rectifier, the charger, and the output rectifier form a charging power path having two stages, including a first stage being a bridge rectifier front end with a Boost converter and a second stage being an isolated DC/DC rear end.
3. The reconfigurable traction-charging system of claim 2 , wherein at least one stator winding on one or more stator teeth of the motor constitutes at least one Boost inductor of the Boost converter.
4. The reconfigurable traction-charging system of claim 1 , wherein
the external power supply is a single or split single phase power supply;
the system further comprises an input bridge rectifier; and
the input bridge rectifier, the charger, and the output rectifier form a charging path having two stages, including a first stage being a bridge PFC rectifier front end with a Boost converter and a second stage being an isolated DC/DC rear end.
5. The reconfigurable traction-charging system of claim 4 , wherein at least one stator winding on one or more stator teeth of the motor constitutes at least one Boost inductor of the Boost converter.
6. The reconfigurable traction-charging system of claim 1 , wherein
the external power supply is a multiple phase power supply; and
the charger and the output rectifier form a charging path having two stages, including a first stage being a multiple phase Boost PFC front end and a second stage being an isolated DC/DC rear end.
7. The reconfigurable traction-charging system of claim 1 , wherein
the external power supply is a single phase or single split phase power supply; and
the charger and the output rectifier form a charging path having two stages, including a first stage being a single phase Boost PFC front end and a second stage being an isolated DC/DC rear end.
8. The reconfigurable traction-charging system of claim 1 , wherein
the external power supply is a single phase or single split phase power supply; and
the system further comprises two diodes, wherein the two diodes, the charger, and the output rectifier form a charging path having two stages, including a first stage being a single phase Totem-Pole Boost PFC front end stage and a second stage being an isolated DC/DC rear end stage.
9. A method for implementing a reconfigurable traction-charging system residing in an electric apparatus having a rechargeable battery, the method comprising:
configuring, via a configurator, under control of a controller, the reconfigurable traction-charging system to operate in a traction mode;
upon receiving a request to charge the rechargeable battery, configuring, via the configurator, the reconfigurable traction-charging system to operate in a charging mode; and
upon determining that a criterion associated the rechargeable battery is met, configuring, via the configurator, the reconfigurable traction-charging system to operate in the traction mode,
wherein: the reconfigurable traction-charging system comprises the controller, the configurator, a motor, an inverter and an output rectifier;
the motor comprises a stator having a plurality of stator teeth and a plurality of stator windings wound on the plurality of stator teeth, wherein a stator winding on at least one stator tooth of the motor is split into two or more coils, wherein the two or more coils have distinct connections for the traction mode and the charging mode;
the inverter comprises a plurality of power switch devices, the configurator comprises a plurality of contactors coupled with the plurality of stator windings and the plurality of power switch devices
wherein
under the traction mode, the rechargeable battery supplies electric energy to the motor via the inverter; and
under the charging mode, connections associated with the plurality of power switch devices and the stator windings are configured by the configurator to form a charger that draws electric energy from an external power supply to charge the rechargeable battery, and wherein
a stator winding on at least one stator tooth of the motor is split into two or more coils;
under the charging mode, the two or more coils and the corresponding at least one stator tooth form a transformer in the charger; and
under the traction mode, the two or more coils are connected in parallel or in series to form a phase winding.
10. The method for implementing a reconfigurable traction-charging system of claim 9 , wherein
the external power supply is a multiple phase power supply;
the reconfigurable traction-charging system further comprises an input bridge rectifier; and
the input bridge rectifier, the charger, and the output rectifier form a charging power path having two stages, including a first stage being a bridge rectifier front end with a Boost converter and a second stage being an isolated DC/DC rear end.
11. The method for implementing a reconfigurable traction-charging system of claim 10 , wherein at least one stator winding on one or more stator teeth of the motor constitutes at least one Boost inductor of the Boost converter.
12. The method for implementing a reconfigurable traction-charging system of claim 9 , wherein
the external power supply is a single or split single phase power supply;
the reconfigurable traction-charging system further comprises an input bridge rectifier; and
the input bridge rectifier, the charger, and the output rectifier form a charging path having two stages including a first stage being a bridge PFC rectifier front end with a Boost converter and a second stage being an isolated DC/DC rear end.
13. The method for implementing a reconfigurable traction-charging system of claim 12 , wherein at least one stator winding on one or more stator teeth of the motor constitutes at least one Boost inductor of the Boost converter.
14. The method for implementing a reconfigurable traction-charging system of claim 9 , wherein
the external power supply is a multiple phase power supply; and
the charger and the output rectifier form a charging path having two stages, including a first stage being a multiple phase Boost PFC front end and a second stage being an isolated DC/DC rear end.
15. The method for implementing a reconfigurable traction-charging system of claim 9 , wherein
the external power supply is a single phase or single split phase power supply; and
the charger and the output rectifier form a charging path having two stages, including a first stage being a single phase Boost PFC front end and a second stage being an isolated DC/DC rear end.
16. The method for implementing a reconfigurable traction-charging system of claim 9 , wherein
the external power supply is a single phase or single split phase power supply; and
the reconfigurable traction-charging system further comprises two diodes, wherein the two diodes, the charger, and the output rectifier form a charging path having two stages, including a e second stage being an isolated DC/DC rear end stage.