Solar panel power point tracker integrated with vehicle electrical system

Patent metadata

Field	Value
Publication number	US-10220709-B2
Application number	US-201715486640-A
Country	US
Kind code	B2
Filing date	Apr 13, 2017
Priority date	Apr 13, 2017
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

A voltage quality module (VQM) function and a solar power generation function are integrated by sharing a single voltage converter (VC) within the electrical system of an automotive vehicle with an electric-start internal combustion engine. The cost of adding solar power generating capabilities to vehicles, the packaging complexities of the systems, and the number of added components are all decreased. The VC can be a DC-DC converter in a boost mode or a buck mode. A switching circuit selectably couples the VC between a main battery and an accessory bus or to between a solar panel and an auxiliary battery. A VC controller regulating a VC output using the main battery to stabilize an accessory bus voltage when in an engine crank mode and otherwise regulating the VC output to match an auxiliary battery voltage using the solar panel output.

First claim

What is claimed is:

1. Apparatus for a vehicle with an electric-start internal combustion engine, comprising:
a DC accessory bus configured to connect to a plurality of electrical accessories;
a primary DC bus adapted to connect to a main DC battery and to an electric starter for the engine;
a voltage quality unit including a voltage converter configured to convert a voltage on the primary DC bus to a stabilized voltage on the DC accessory bus during a starting operation of the electric starter, wherein the voltage quality unit includes bypass switches for connecting the primary DC bus to the DC accessory bus when the electric starter is not in the starting operation; and
a solar panel generating an output voltage at a panel output;
wherein the bypass switches further connect the voltage converter between the panel output and an auxiliary load when the electric starter is not in the starting operation, and wherein the voltage converter converts the solar panel output voltage to an optimized voltage that optimizes power transfer to the auxiliary load.

2. The apparatus of claim 1 wherein the stabilized voltage is a predetermined nominal voltage of the main DC battery.

3. The apparatus of claim 1 wherein the voltage converter is a boost converter.

4. The apparatus of claim 1 wherein the auxiliary load is comprised of an auxiliary battery that is charged by the solar panel, and wherein the optimized voltage is a predetermined nominal voltage of the auxiliary battery.

5. The apparatus of claim 1 wherein the auxiliary load is comprised of at least one DC load.

6. The apparatus of claim 5 wherein the DC load includes a DC-AC inverter providing AC power to an AC load.

7. The apparatus of claim 1 further comprising a controller configured to a) detect the starting operation, b) set the bypass switches via at least one magnetic relay, and c) control a duty cycle of the voltage converter to regulate the stabilized voltage and the optimized voltage, respectively.

8. The apparatus of claim 1 further comprising a flow reversal switch interconnecting the solar panel, voltage converter, and auxiliary load to select either a boost mode or a buck mode of the voltage converter as necessary to produce the optimized voltage.

9. An automotive electrical system, comprising:
a DC-DC converter;
a switching circuit selectably coupling the converter between a main battery and an accessory bus during an engine crank mode or otherwise between a solar panel and an auxiliary battery; and
a controller regulating a converter output using the main battery to stabilize an accessory bus voltage during crank mode and otherwise using the solar panel to match a voltage of the auxiliary battery.

10. The system of claim 9 wherein the accessory bus voltage is stabilized at a predetermined nominal voltage of the main battery.

11. The system of claim 9 wherein the converter is a boost converter.

12. The system of claim 9 the controller is configured to a) detect the engine crank mode, b) set the switching circuit via at least one magnetic relay, and c) control a duty cycle of the converter to regulate the accessory bus voltage and the matching voltage, respectively.

13. The system of claim 9 further comprising a flow reversal switch interconnecting the solar panel, converter, and auxiliary battery to select either a boost mode or a buck mode of the converter as necessary to produce the matching voltage.

14. A control method for a voltage converter (VC) in a combustion vehicle, comprising:
converting solar power from a solar panel to an optimized voltage for charging an auxiliary battery;
detecting cranking of a starter in the vehicle;
during cranking, disconnecting the VC from the solar panel and converting a main battery power to a predetermined bus voltage for powering electrical accessories; and
after cranking, reconnecting the VC to the solar panel and auxiliary battery.

15. The method of claim 14 wherein during cranking the VC is connected to provide a power flow in a first direction through the VC, and wherein the VC is connected to provide a power flow in an opposite direction through the VC during conversion of solar power.

16. The method of claim 14 wherein an input of the VC is switched to the main battery during cranking and switched to the solar panel otherwise.

Assignees

• Ford Global Tech Llc

Inventors

• Malek Hadi
• Boston Daniel
• Mathews Jacob
• Lathrop James A

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• G05F1/67

  to the maximum power available from a generator, e.g. from solar cell · CPC title

• B60L8/003 Primary

  Converting light into electric energy, e.g. by using photo-voltaic systems · CPC title

• B60L2210/12

  Buck converters · CPC title