Predictive current control in bidirectional power converter

• US 9,698,700 B2
• Filed: 03/11/2015
• Issued: 07/04/2017
• Est. Priority Date: 03/11/2015
• Status: Active Grant

• Current Assignee: DRS Naval Power Systems, Inc. (Leonardo S.p.A.), University of Connecticut (State of Connecticut)
• Original Assignee: DRS Consolidated Controls, Inc., University of Connecticut (State of Connecticut)
• Inventors: Tarca, Matthew, Thompson, John, Gellis, David, Ramsay, Scott, Kelley, Michael, Parsons, Thomas, Park, Sung Yeul, Park, Sungmin
• Primary Examiner(s): Nguyen, Matthew
• Assistant Examiner(s): JAMALI, ISHRAT F
• Application Number:
  US14/645,355
• Publication Number:
  US 20160268917A1
• Time in Patent Office: 846 Days
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2260/50 by future state prediction
• CPC Class Codes: B60L 2260/54 Energy consumption estimation
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 55/00 Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H02M 5/293 using semiconductor devices only
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02M 7/4807 having a high frequency intermediate AC stage
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/53873 with digital control
• CPC Class Codes: H02M 7/79 using devices of a triode or transistor type requiring continuous application of a control signal
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]

Abstract

A power converter can be controlled to generate a target output power. The control process may include obtaining a target current reference for the power converter, sensing an output current of the power converter, and determining a difference between the target current reference and the sensed output current. The next switching duty cycle for the next switching period of the switching circuits in the power converter can be derived based on at least the present switching duty cycle of the present switching period, and the difference between the target current reference and the sensed output current. The switching circuits of the power converter can then be switched according to the derived next switching duty cycle in the next switching period.

Claims

1. A method for controlling a power converter that includes a plurality of switching circuits switching according to a switching period to generate a target output power, the method comprising:

obtaining a target current reference for the power converter;

sensing an output current of the power converter;

determining a difference between the target current reference and the sensed output current;

deriving a next switching duty cycle for a next switching period based on at least a present switching duty cycle of the present switching period, and the difference between the target current reference and the sensed output current, wherein the next switching duty cycle is derived further based on a sum of a present output voltage of the power converter in the present switching period and a previous output voltage of the power converter in a previous switching period; and

switching the plurality of switching circuits of the power converter according to the derived next switching duty cycle in the next switching period.

2. The method of claim 1, further comprising:

inserting a dead time in the switching period in which switching circuits on a same leg of the power converter are kept off.

3. The method of claim 2, wherein the next switching duty cycle is derived further based on the dead time.

4. The method of claim 1, wherein the next switching duty cycle is derived further based on a leakage inductance of a transformer of the power converter.

5. The method of claim 1, wherein the target current reference includes a current ripple compensation component.

6. The method of claim 1, wherein the power converter is operable to inject power into a power grid.

7. The method of claim 1, wherein the power converter is part of an electric vehicle.

8. A power converter comprising:

a plurality of switching circuits operating according to a switching period; and

a switch controller including;

a current reference generator configured to generate a target current reference; and

a predictive current controller configured to receive the target current reference from the current reference generator, and derive a next switching duty cycle for a next switching period based on at least a present switching duty cycle of the present switching period and a difference between the target current reference and an output current of the power converter, wherein the next switching duty cycle is derived further based on a sum of a present output voltage of the power converter in the present switching period and a previous output voltage of the power converter in a previous switching period, and wherein the derived next switching duty cycle is applied to the plurality of switching circuits in the next switching period.

9. The power converter of claim 8, wherein a dead time is inserted into the switching period.

10. The power converter of claim 9, wherein the next switching duty cycle is derived further based on the dead time.

11. The power converter of claim 8, wherein the next switching duty cycle is derived further based on a leakage inductance of a transformer of the power converter.

12. The power converter of claim 8, wherein the target current reference includes a current ripple compensation component.

13. The power converter of claim 8, wherein the power converter includes an AC-AC converter coupled to a DC-AC converter.

14. The power converter of claim 13, wherein the AC-AC converter includes a cyclo-inverter.

15. The power converter of claim 13, wherein the DC-DC converter includes a H-bridge inverter.

16. The power converter of claim 8, further comprising a DC-DC converter coupled to the DC-AC converter.

17. The power converter of claim 16, wherein the DC-DC converter includes a buck-boost circuit.

18. The power converter of claim 8, wherein the power converter is coupled to an electric vehicle battery.