Power share converter for connecting multiple energy storage systems

• US 10,457,159 B1
• Filed: 08/29/2016
• Issued: 10/29/2019
• Est. Priority Date: 10/20/2010
• Status: Active Grant

• Current Assignee: Motiv Power Systems, Inc.
• Original Assignee: Motiv Power Systems, Inc.
• Inventors: Castelaz, Jim Michael, Stein, Elias, Treichler, William
• Primary Examiner(s): Barnie, Rexford N
• Assistant Examiner(s): Vu, Toan T
• Application Number:
  US15/250,906
• Time in Patent Office: 1,156 Days
• Field of Search: 307 25
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• 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 1/346 Passive non-dissipative snubbers
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 29/66 Controlling or determining the temperature of the rotor
• 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 10/92 : Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

A system comprises a plurality of power converters, a plurality of energy storage systems, a first common node, a second common node, and zero-reference voltage node. Each power converter is coupled between one energy storage system and the first and second common nodes. The system operates to regulate power between the power converters and the first and second common nodes. Each power converter is a bi-directional power converter and each energy storage system is a battery pack. In one example, the first common node is regulated to a voltage VSPAN, and the second common node is regulated to a voltage VSCN which is the mean of all voltages output by the battery packs. In another example, the first common node is regulated to a voltage −VSPAN, and the second common node is regulated to a voltage +VSPAN. No power converter processes more than voltage VSPAN yielding high-efficiency power conversion.

Claims

1. A system comprising:

a first energy storage system having a first terminal and a second terminal, wherein the second terminal of the first energy storage system is coupled to a zero-voltage reference node;

a second energy storage system having a first terminal and a second terminal, wherein the second terminal of the second energy storage system is coupled to the zero-voltage reference node;

a first power converter having an ESS-side node and two share nodes, wherein the ESS-side node of the first power converter is coupled to the first terminal of the first energy storage system;

a second power converter having an ESS-side node and two share nodes, wherein the ESS-side node of the second power converter is coupled to the first terminal of the second energy storage system, wherein the first share node of the second power converter is coupled to the first share node of the first power converter, and wherein the second share node of the second power converter is coupled to the second share node of the first power converter; and

a power supply or load connected between at least one share node and the zero-voltage reference node, wherein each of the first power converter and the second power converter is configured to withstand less than a maximum ESS voltage.

2. The system of claim 1, wherein the first energy storage system is a first battery pack, wherein the second energy storage system is a second battery pack, wherein the first power converter has an amount of circuitry configurable to operate as a bi-directional DC-to-DC power converter, wherein the second power converter has an amount of circuitry configurable to operate as a bi-directional DC-to-DC power converter.

3. The system of claim 1 further comprising:

a power control unit configured to control the first and second power converters via a communication bus, wherein the power control unit is operable to control the first power converter to regulate power between the first energy storage system and the power supply or load during a period of time, wherein the first energy storage system outputs a first voltage during the period of time, wherein the power control unit is operable to control the second power converter to regulate power between the second energy storage system and the power supply or load during the period of time, wherein the second energy storage system outputs a second voltage during the period of time, and wherein the second voltage is different from the first voltage.

4. The system of claim 3, wherein the power control unit controls the power converters to regulate the voltage on one or more of the power converter share nodes to be substantially constant during the period of time, and wherein the voltage on one of the power converter share nodes is substantially equivalent to the mean voltage output by all energy storage systems of the system.

5. The system of claim 3, wherein the power control unit controls the power converters to regulate the voltage on both of the power converter share nodes to be substantially constant during the period of time, and wherein the mean voltage of the power converter share nodes is substantially equivalent to the mean voltage output by all energy storage systems of the system.

6. The system of claim 1, wherein the first power converter has one and only one ESS-side node and two and only two share nodes, wherein the second power converter has one and only one ESS-side node and two and only two share nodes, wherein the first power converter is of a same power converter type as the second power converter, and wherein the first power converter has a substantially identical structure to the second power converter.

12. The system of claim 1, wherein the system is a power system of an electric vehicle, and wherein the power supply or load comprises at least one power component taken from the group consisting of:

an electric motor, an inverter, an HVAC system, DC-to-DC converter, and a vehicle charger.

7. A system comprising:

a first energy storage system having a first terminal and a second terminal, wherein the second terminal of the first energy storage system is coupled to a zero-voltage reference node;

a second energy storage system having a first terminal and a second terminal, wherein the second terminal of the second energy storage system is coupled to the zero-voltage reference node;

a first power converter having an ESS-side node and two share nodes, wherein the ESS-side node of the first power converter is coupled to the first terminal of the first energy storage system;

a second power converter having an ESS-side node and two share nodes, wherein the ESS-side node of the second power converter is coupled to the first terminal of the second energy storage system, wherein the first share node of the second power converter is coupled to the first share node of the first power converter, and wherein the second share node of the second power converter is coupled to the second share node of the first power converter; and

a power supply or load connected between at least one share node and the zero-voltage reference node, wherein the first power converter has an amount of power circuitry, and wherein the power circuitry comprises;

a first switch SW1 having a first terminal T1, a second terminal T2, and a third terminal T3;

a second switch SW2 having a first terminal T1, a second terminal T2, and a third terminal T3;

a third switch SW3 having a first terminal T1, a second terminal T2, and a third terminal T3;

a fourth switch SW4 having a first terminal T1, a second terminal T2, and a third terminal T3;

a first inductor L1 having a first lead and a second lead, wherein the first lead of the first inductor L1 is coupled to the first terminal of the first energy storage system, wherein the second lead of the first inductor L1 is coupled to the second terminal T2 of the first switch SW1, and wherein the second lead of the first inductor L1 is also coupled to the first terminal T1 of the second switch SW2; and

a second inductor L2 having a first lead and a second lead, wherein the first lead of the second inductor L2 is coupled to the second terminal T2 of the third switch SW3, wherein the first lead of the second inductor L2 is also coupled to the first terminal T1 of the fourth switch SW4, and wherein the second lead of the second inductor L2 is coupled to a share node.

8. The system of claim 7, further comprising:

a capacitor having a first lead and a second lead, wherein the first lead of the capacitor is coupled to the first terminal of the first switch SW1, wherein the first lead of the capacitor is also coupled to the first terminal of the third switch SW3, wherein the second lead of the capacitor is coupled to the second terminal of the second switch SW2, and wherein the second lead of the capacitor is also coupled to the second terminal of the fourth switch SW4.

9. The system of claim 7, wherein the first terminal of the first switch SW1 is capacitively coupled to the first lead of the first inductor L1, wherein the second terminal of the second switch SW2 is capacitively coupled to the first lead of the first inductor L1, wherein the first terminal of the third switch SW3 is capacitively coupled to the second lead of the second inductor L2, and wherein the second terminal of the fourth switch SW4 is capacitively coupled to the second lead of the second inductor L2.

10. The system of claim 7, further comprising:

a switching circuit that is coupled between the second lead of the first inductor L1 and one of the power converter nodes, wherein the switching circuit comprises;

a third inductor L3 having a first lead and a second lead, wherein the first lead of the third inductor L3 is coupled to the second lead of the first inductor L1; and

a fifth switch SW5 having a first terminal T1, a second terminal T2, and a third terminal T3, wherein the second lead of the third inductor L3 is coupled to the first terminal T1 of the fifth switch SW5, wherein the second terminal T2 of the fifth switch SW5 is coupled to a power converter node.

11. The system of claim 7, further comprising:

a switching circuit that is coupled between the first lead of the second inductor L2 and one of the power converter nodes, wherein the switching circuit comprises;

an inductor L4 having a first lead and a second lead, wherein the first lead of the inductor L4 is coupled to the first lead of the second inductor L2;

a switch SW7 having a first terminal T1, a second terminal T2, and a third terminal T3, wherein the second lead of the inductor L4 is coupled to the first terminal T1 of the switch SW7, wherein the second terminal T2 of the switch SW7 is coupled to a power converter node.

13. A method comprising:

(a) coupling a first share node of a first power converter to a first share node of a second power converter, wherein the first power converter is of a power converter type, wherein the second power converter is of the power converter type, wherein first power converter is adapted to be coupled to a first energy storage system, and wherein second power converter is adapted to be coupled to a second energy storage system; and

(b) coupling a second share node of the first power converter to a power supply or load and coupling a second share node of the second power converter to the power supply or load, wherein neither the first power converter nor second power converter is configured to handle more than two times a maximum deviation between output voltages of the first energy storage system and the second energy storage system.

14. The method of claim 13, further comprising:

(c) causing energy stored in the first energy storage system and second energy storage system to be transferred to the power load for a duration of time, wherein during the duration of time, the first energy storage system has a first voltage and the second energy storage system has a second voltage different from the first voltage.

15. The method of claim 13, further comprising:

(c) causing energy from the power supply to be transferred to the first energy storage system and second energy storage system for a duration of time, wherein during the duration of time, the first energy storage system has a first voltage and the second energy storage system has a second voltage different from the first voltage.

16. The method of claim 13, further comprising:

(c) causing energy stored in the first energy storage system to be transferred to the second energy storage system.

17. The method of claim 13, wherein the supply or load of (b) includes a second-stage power converter.

18. The method of claim 13, wherein the first power converter has a single node for connection to an energy storage system, wherein the first power converter has only two share nodes, wherein the second power converter has a single node for connection to an energy storage system, and wherein the second power converter has only two share nodes.

19. The method of claim 13, A method comprising:

(a) coupling a first share node of a first power converter to a first share node of a second power converter, wherein the first power converter is of a power converter type, wherein the second power converter is of the Power converter type, wherein first power converter is adapted to be coupled to a first energy storage system, and wherein second power converter is adapted to be coupled to a second energy storage system; and

(b) coupling a second share node of the first power converter to a Power supply or load and coupling a second share node of the second Power converter to the power supply or load, wherein the first power converter has an amount of power circuitry, and wherein the power circuitry comprises;

a first switch SW1 having a first terminal T1, a second terminal T2, and a third terminal T3;

a second switch SW2 having a first terminal T1, a second terminal T2, and a third terminal T3;

a third switch SW3 having a first terminal T1, a second terminal T2, and a third terminal T3;

a fourth switch SW4 having a first terminal T1, a second terminal T2, and a third terminal T3;

a first inductor L1 having a first lead and a second lead, wherein the first lead of the first inductor L1 is coupled to the first terminal of the first energy storage system, wherein the second lead of the first inductor L1 is coupled to the second terminal T2 of the first switch SW1, and wherein the second lead of the first inductor L1 is also coupled to the first terminal T1 of the second switch SW2; and

a second inductor L2 having a first lead and a second lead, wherein the first lead of the second inductor L2 is coupled to the second terminal T2 of the third switch SW3, wherein the first lead of the second inductor L2 is also coupled to the first terminal T1 of the fourth switch SW4, and wherein the second lead of the second inductor L2 is coupled to a share node.

20. The method of claim 19, further comprising:

a capacitor having a first lead and a second lead, wherein the first lead of the capacitor is coupled to the first terminal of the first switch SW1, wherein the first lead of the capacitor is also coupled to the first terminal of the third switch SW3, wherein the second lead of the capacitor is coupled to the second terminal of the second switch SW2, and wherein the second lead of the capacitor is also coupled to the second terminal of the fourth switch SW4.

21. A system comprising:

a power supply or load connected between at least one power converter share node and a zero-voltage reference node; and

means for regulating the power supply or load connected to one of the power converter share nodes, wherein the means is also for receiving a current from another of the power converter share nodes, and wherein no voltage between two power converter share nodes exceeds half of a maximum ESS voltage of the system.

22. The system of claim 21, wherein the means is a power converter having a ESS-side node coupled to an energy storage system, and wherein the power converter is coupled to each of the power converter share nodes.

23. The system of claim 21, wherein a voltage VSPAN+ is present on one of the power converter share nodes, and wherein the voltage VSPAN+ is equal to or greater than a maximum energy storage system voltage.

24. The system of claim 21, wherein a voltage VSPAN−

is present on one of the power converter share nodes, and wherein the voltage VSPAN−

is equal to or less than a minimum energy storage system voltage.

25. The system of claim 21, wherein a mean of voltages present on the power converter share nodes is equal to a mean energy storage system voltage.

26. The system of claim 21, wherein a voltage present on one of the power converter share nodes is equal to a mean energy storage system voltage.