Constant current fast charging of electric vehicles via DC grid using dual inverter drive
AssigneesThe Governing Council of the University of Toronto, Eleappower Ltd.
InventorsPeter Waldemar Lehn, Ruoyun Shi, Theodore Soong
Life of this patent
Estimating the term…
Abstract
A switching circuit for controlling charging input from a DC source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery, the switching circuit is provided with a switching device which when positioned in series with the inverter circuit and the DC source, the switching device configured to control the charging input provided to the at least one respective battery, the switching device controllable in conjunction with switches in the at least one inverter circuit based on at least one voltage of the at least one respective battery.
Claims30
A device adapted to provide both drive and charging functionality from a DC power source, the device comprising:
- an electric motor;
- a first inverter circuit including a first traction inverter and a first battery coupled to the electric motor and to a DC front-end circuit;
- a second inverter circuit including a second traction inverter and a second battery coupled to the electric motor and the DC front-end circuit, the DC front-end circuit coupled to the DC power source and the first inverter circuit and the second inverter circuit;
- a first connection node connecting a negative terminal of the second battery and the DC front-end circuit, the second battery connected in parallel with the second traction inverter;
- a second connection node connecting a positive terminal of the first battery and the DC front-end circuit, the first battery connected in parallel with the first traction inverter;
- the first battery and the second battery exchanging power with the DC power source;
- a diode or an active switch coupled between the first connection node and the second connection node;
- a capacitor connected in parallel with the diode or the active switch;
- the DC front-end circuit including at least one switching device, positioned on a circuit connection between the diode or the active switch and the capacitor, configured to control a charging input from the DC power source provided to at least one of the first and the second batteries, the at least one switching device controllable in conjunction with switches in at least one of the first inverter circuit and the second inverter circuit;
- wherein when a sum of voltages of the first battery and the second battery are less than or equal to an input voltage of the DC power source, the at least one switching device is configured to control the charging input by operating in a first mode that inserts both the first battery and the second battery into a circuit conduction path by either modulating the at least one switching device or modulating the switches of the first traction inverter and the second traction inverter;
- and
- when the sum of the voltages of the first battery and the second battery are greater than the input voltage of the DC power source, the at least one switching device is configured to control the charging input by operating in a second mode switching on the at least one switching device and modulating the switches of the first traction inverter and the second traction inverter.
A front-end switching circuit for controlling charging input from a DC power source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery, the front-end switching circuit comprising:
- at least one switching device which when positioned in series with the at least one inverter circuit and the DC source, the at least one switching device is configured to control the charging input provided to the at least one respective battery, the at least one switching device controllable in conjunction with switches in the at least one inverter circuit based on at least one voltage of the at least one respective battery.
A method for controlling charging input from a DC power source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery, the method comprising:
- controlling at least one switching device, positioned in series with the at least one inverter circuit and the DC power source, in conjunction with switches in the at least one inverter circuit based on at least one voltage of the at least one respective battery;
- wherein the at least one switching device is positioned to control a charging input from the DC source to a first inverter circuit corresponding to a first battery and a second inverter circuit corresponding to a second battery, the method comprising:
- when a sum of the voltages of the first battery and the second battery are less than or equal to an input voltage of the DC power source, controlling the at least one switching device to operate in a first mode that inserts both the first battery and the second battery into a circuit conduction path by either modulating the at least one switching device or modulating the switches of the first inverter circuit and the second inverter circuit;
- and
- when a sum of the voltages of the first battery and the second battery are greater than the input voltage of the DC power source, controlling the switching device to operate in a second mode switching on the at least one switching device and modulating the switches of the first inverter circuit and the second inverter circuit.
A DC front-end circuit for controlling charging input from a DC power source to (i) a first inverter circuit, including a first traction inverter and a first battery, adapted to be coupled to an electric motor configured for drive and charging functionality from the DC power source, and (ii) a second inverter circuit, including a second traction inverter and a second battery, adapted to be coupled to the electric motor and the DC front-end circuit, the DC front-end circuit comprising:
- a first connection node connecting the negative terminal of the second battery and the DC front-end circuit, the second battery connected in parallel with the second traction inverter;
- a second connection node connecting the positive terminal of the first battery and the DC front-end circuit, the first battery connected in parallel with the first traction inverter;
- a diode or an active switch coupled between the first connection node and the second connection node;
- a capacitor connected in parallel with the diode or the active switch;
- at least one switching device, positioned on a circuit connection between the diode or the active switch and the capacitor, configured to control the charging input provided from the DC power source to at least one of the first and the second batteries, the at least one switching device controllable in conjunction with switches in the at least one of the first inverter circuit and the second inverter circuit wherein when a sum of the voltages of the first battery and the second battery are less than or equal to an input voltage of the DC power source, the at least one switching device is configured to control the charging input by operating in a first mode that inserts both the first battery and the second battery into a circuit conduction path by either modulating the at least one switching device or modulating the switches of the first traction inverter and the second traction inverter;
- and
- when the sum of the voltages of the first battery and the second battery are greater than the input voltage of the DC power source, the at least one switching device is configured to control the charging input by operating in a second mode switching on the at least one switching device and modulating the switches of the first traction inverter and the second traction inverter.
Dependencies are inferred from the claim text.