Electric vehicle power supply system to minimize loss during vehicle rest

Patent metadata

Field	Value
Publication number	US-11021073-B1
Application number	US-202016801702-A
Country	US
Kind code	B1
Filing date	Feb 26, 2020
Priority date	Feb 26, 2020
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A power management system for an electric vehicle is provided which maintains power to the various vehicle ‘always-on’ components and subsystems during periods of vehicle non-use without requiring the low voltage battery to undergo frequent charge/discharge cycling. The system uses a secondary DC/DC converter that has a lower output voltage, and operates at a higher efficiency, then the primary DC/DC converter. As a result of this system, the life of the low voltage battery is prolonged and power consumption efficiency is improved, thereby minimizing range loss while the car is parked.

First claim

What is claimed is:

1. An electric vehicle (EV) power management system, comprising:
a high voltage (HV) battery;
a primary DC/DC converter;
a vehicle power switch adjustable between an on position and an off position, wherein said primary DC/DC converter is electrically connected to said HV battery when said vehicle power switch is in said on position, wherein said primary DC/DC converter provides a first power source of a first voltage on a first power line when said vehicle power switch is in said on position, wherein said primary DC/DC converter is electrically disconnected from said HV battery when said vehicle power switch is in said off position, and wherein said primary DC/DC converter ceases to provide said first power source on said first power line when said vehicle power switch is in said off position;
a secondary DC/DC converter, wherein said secondary DC/DC converter is electrically connected to said HV battery and remains electrically connected to said HV battery both when said vehicle power switch is in said on position and when said vehicle power switch is in said off position, wherein said secondary DC/DC converter provides a second power source of a second voltage on a second power line, and wherein said second voltage is lower than said first voltage;
an electronic control unit (ECU), wherein said ECU is electrically connected to at least one EV electrical component; and
a switching circuit electrically connected to said ECU and configured to select between electrically connecting said first power line to said ECU and electrically connecting said second power line to said ECU, wherein said switching circuit electrically connects said first power line to said ECU when said first voltage on said first power line is greater than said second voltage on said second power line, and wherein said switching circuit electrically connects said second power line to said ECU when said second voltage is greater than a voltage on said first power line.

2. The EV power management system of claim 1 , wherein said switching circuit selects between said first power line and said second power line based on voltage levels.

3. The EV power management system of claim 2 , further comprising a secondary battery electrically connected to said first power line, wherein a resting voltage of said secondary battery is less than said first voltage, and wherein said resting voltage of said secondary battery is less than said second voltage.

4. The EV power management system of claim 3 , wherein said switching circuit electrically connects said second power line to said ECU when said second voltage on said second power line is greater than said voltage on said first power line.

5. The EV power management system of claim 3 , wherein said switching circuit electrically connects said first power line to said ECU when said resting voltage of said secondary battery on said first power line is greater than an output of said first power source provided by said primary DC/DC converter and said resting voltage of said secondary battery on said first power line is greater than an output of said second power source provided by said secondary DC/DC converter.

6. The EV power management system of claim 3 , wherein said switching circuit electrically connects said first power line to said ECU when said vehicle power switch is in said off position and a malfunction in said secondary DC/DC converter causes said secondary DC/DC converter to output a voltage less than said resting voltage of said secondary battery.

7. The EV power management system of claim 3 , wherein said switching circuit electrically connects said first power line to said ECU when a malfunction in said primary DC/DC converter causes said primary DC/DC converter to output a voltage less than said resting voltage of said secondary battery and a malfunction in said secondary DC/DC converter causes said secondary DC/DC converter to output a voltage less than said resting voltage of said secondary battery.

8. The EV power management system of claim 3 , wherein said first power source charges said secondary battery when said vehicle power switch is in said on position and said primary DC/DC converter provides said first power source on said first power line.

9. The EV power management system of claim 2 , said at least one EV electrical component selected from the group consisting of a power door lock, a power window, a power seat, an internal light, an external light, a vehicle alarm system, a vehicle entertainment system, a HVAC fan, a GPS system, an airbag system, a seatbelt pre-tensioner, an ABS system, a brake booster vacuum pump, a steering assist system, and a vehicle monitoring system.

10. The EV power management system of claim 2 , wherein said vehicle power switch determines a vehicle operational status.

11. The EV power management system of claim 2 , wherein said second power source provided by said secondary DC/DC converter is capable of closing a set of HV battery contactors.

Assignees

• Atieva Inc

Inventors

• Gauthier Jean-Philippe
• Djock Matthew
• Biskup Richard

Classifications

• H02M3/00

  Conversion of DC power input into DC power output · CPC title

• B60L58/20 Primary

  having different nominal voltages · CPC title

• B60L1/00

  Supplying electric power to auxiliary equipment of vehicles (circuit arrangements for charging batteries H02J7/00) · CPC title

• B60L3/0046

  relating to electric energy storage systems, e.g. batteries or capacitors · CPC title

• B60L2210/10

  DC to DC converters · CPC title