UAV HYBRID POWER SYSTEMS AND METHODS

• US 20170203850A1
• Filed: 03/31/2017
• Published: 07/20/2017
• Est. Priority Date: 12/31/2015
• Status: Active Grant

• Current Assignee: SZ DJI Technology Co., Ltd. (d/b/a DJI) (iFlight Technology Company Limited)
• Original Assignee: SZ DJI Technology Co., Ltd. (d/b/a DJI) (iFlight Technology Company Limited)
• Inventors: Wang, Wentao, Zheng, Dayang, Zhan, Juncheng, Liu, Yuancai, Wang, Lei
• Granted Patent: US 10,501,195 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 2041/005 Fuel cells
• CPC Class Codes: B64D 2221/00 Electric power distribution systems onboard aircraft
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: B64D 27/353 using solar cells
• CPC Class Codes: B64D 41/00 Power installations for auxiliary purposes
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 30/20 Rotors; Rotor supports
• CPC Class Codes: B64U 50/19 using electrically powered motors
• 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 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

Systems, methods, and devices are provided herein for improving the power performance of vehicle. A hybrid power system may comprise a power controller adapted to be in communication with a first power source, a second power source, and a load. The power controller may be configured to detect whether a current drawn by the load exceeds a predetermined threshold, control discharging of the first power source without permitting discharging of the second power source to power the load when the current drawn by the load is less than the predetermined threshold current, and control discharging of the first power source and the second power source to power the load when the current drawn by the load is greater than the predetermined threshold current.

Claims

1. A hybrid power system comprising:

a power controller adapted to be in communication with a first power source, a second power source, and a load, wherein the power controller is configured to;

detect whether a current drawn by the load exceeds a predetermined threshold current;

control discharging of the first power source without permitting discharging of the second power source to power the load when the current drawn by the load is less than the predetermined threshold current; and

control discharging of the first power source and the second power source to power the load when the current drawn by the load is greater than the predetermined threshold current.

2. The hybrid power system of claim 1, wherein the hybrid power system is located on an unmanned aerial vehicle (UAV).

3. The hybrid power system of claim 2, wherein the load comprises a motor system of the UAV, the motor system being configured to provide a propulsion for the UAV.

4. The hybrid power system of claim 1, wherein the first power source is configured to discharge at a voltage V1 and a current I1 to power the load, wherein the predetermined threshold current corresponds to the current I1 of the first power source, wherein the current drawn by the load is I0 when the current drawn by the load is less than the predetermined threshold current, and wherein the current drawn by the load is I(h) when the current drawn by the load is greater than the predetermined threshold current, wherein the power controller is configured to control the discharging of the first power source and the second power source to power the load when the current drawn by the load is greater than the predetermined threshold current, such that the first power source discharges the current I1 to the load, and the second power source discharges a boost current I(b) to the load, and wherein the boost current I(b) corresponds to a difference between the current I(h) and the current I1.

5. The hybrid power system of claim 4, wherein the second power source has a power density such that the second power source is capable of discharging the boost current I(b) to supplement the current I1 discharged by the first power source when the current drawn by the load is greater than the predetermined threshold current.

6. The hybrid power system of claim 5, wherein the power density of the second power source is higher than the power density of the first power source.

7. The hybrid power system of claim 4, wherein an energy capacity density of the first power source is higher than an energy capacity density of the second power source.

8. The hybrid power system of claim 1, further comprising:

one or more current sensors to detect whether the current drawn by the load exceeds the predetermined threshold current.

9. The hybrid power system of claim 1, further comprising:

a third power source, and wherein the power controller is adapted to be in communication with the first power source, the second power source, the third power source, and the load, wherein the power controller is further configured to;

control discharging of the first power source and the second power source without permitting discharging of the third power source to power the load when the current drawn by the load is greater than the predetermined threshold current and less than a first predetermined threshold current; and

control discharging of the first power source, the second power source, and the third power source to power the load when the current drawn by the load is greater than the first predetermined threshold current.

10. The hybrid power system of claim 9, wherein the first power source is a fuel cell, the second power source is a lithium-ion battery, and the third power source is a super capacitor.

11. The hybrid power system of claim 10, wherein the power controller is further adapted to be in communication with a fourth power source, and wherein the fourth power source is a solar cell.

12. The hybrid power system of claim 9, wherein the first power source is configured to discharge at a voltage V1 and a current I1 to power the load, wherein the predetermined threshold current corresponds to the current I1 of the first power source, wherein the first predetermined threshold current corresponds to a current I2, wherein the current drawn by the load is I0 when the current drawn by the load is less than the predetermined threshold current, and wherein the current drawn by the load is I(h) when the current drawn by the load is greater than the predetermined threshold current.

13. The hybrid power system of claim 12, wherein the power controller is configured to control the discharging of the first power source and the second power source to power the load when I(h)≦

I2, such that the first power source discharges the current I1 to the load, and the second power source discharges a first boost current I(b1) to the load, wherein the first boost current I(b1) corresponds to a difference between the current I(h) and the current I1.

14. The hybrid power system of claim 13, wherein the second power source has a power density such that the second power source is capable of discharging the first boost current I(b1) to supplement the current I1 discharged by the first power source when I(h)≦

I2.

15. The hybrid power system of claim 13, wherein the first predetermined threshold current I2 is set to less than or equal to about twice the value of the predetermined threshold current I1, in order to maintain performance and battery life of the second power source.

16. The hybrid power system of claim 13, wherein the power controller is further configured to control the discharging of the first power source, the second power source, and the third power source to power the load when I(h)>

I2, such that the first power source discharges the current I1 to the load, the second power source discharges the first boost current I(b1) to the load, and the third power source discharges a second boost current I(b2) to the load, wherein the second boost current I(b2) is calculated using the following equation;

I(b2)=I(h)−

I(b1)−

I1.

17. The hybrid power system of claim 16, wherein the third power source has a power density such that the third power source is capable of discharging the second boost current I(b2) to the load to supplement the current I1 discharged by the first power source and the first boost current I(b1) discharged by the second power source when I(h)>

I2.

18. The hybrid power system of claim 9, further comprising:

one or more current sensors to detect whether the current drawn by the load exceeds the predetermined threshold current and/or the first predetermined threshold current.

19. An unmanned aerial vehicle (UAV) comprising:

a load comprising at least one propulsion unit; and

a power controller adapted to be in communication with a first power source, a second power source, and the load, wherein the power controller is configured to;

detect whether a current drawn by the load exceeds a predetermined threshold;

control discharging of the first power source without permitting discharging of the second power source to power the load when the current drawn by the load is less than the predetermined threshold current; and

control discharging of the first power source and the second power source to power the load when the current drawn by the load is greater than the predetermined threshold current.

20. A method for controlling power delivery, the method comprising:

detecting whether a current drawn by the load exceeds a predetermined threshold;

controlling, with aid of one or more processors, discharging of a first power source without permitting discharging of a second power source to power the load when the current drawn by the load is less than the predetermined threshold current; and

controlling, with the aid of the one or more processors, discharging of the first power source and the second power source to power the load when the current drawn by the load is greater than the predetermined threshold current.