Software defined battery charger system and method

Patent metadata

Field	Value
Publication number	US-10663501-B2
Application number	US-201715696641-A
Country	US
Kind code	B2
Filing date	Sep 6, 2017
Priority date	Sep 6, 2017
Publication date	May 26, 2020
Grant date	May 26, 2020

Abstract

A backup battery charging system for a building management system is disclosed. Components of the charging system include an analog power converter, a voltage feedback loop and a current feedback loop. The feedback loops each include at least one digital resistor. The system panel, in turn, includes at least one microcontroller that controls the building management system and also controls the charging system. The charging system is “software defined,” in that the microcontroller controls the charging system by updating the digital resistors in the feedback loops to control the analog power converter. In one example, the building management system is a fire alarm system controlled by a fire control panel as the system panel.

First claim

What is claimed is:

1. A building management system, comprising:
a system panel for controlling the building management system including at least one microcontroller;
a backup battery system for powering the system panel; and
a charging system for charging the backup battery system, including an analog power converter that provides an output current at an output voltage to the backup battery system under control of the microcontroller;
wherein the microcontroller controls the output voltage by updating a register within an output voltage digital resistor of a voltage feedback loop of the charging system.

2. The system of claim 1 , wherein the system panel is a fire control panel, and wherein the fire control panel is included within a fire alarm system that operates as the building management system.

3. The system of claim 1 , wherein the microcontroller additionally controls a detection circuit including fire sensor devices, controls a notification circuit including notification devices, monitors a power bus that provides a primary source of input power to the system panel, and sends notifications to a central station in response to receiving indications of fire from the fire sensor devices.

4. The system of claim 1 , wherein the microcontroller stores one or more charging profiles for the charging system to apply to the backup battery system for charging the backup battery system, and wherein the charging profiles include:
a target voltage, and a target current for defining a maximum output current; and
a temperature compensation table that provides a temperature compensation voltage based upon a temperature of batteries in the backup battery system.

5. The system of claim 4 , wherein the target voltage within each charging profile is based on chemistry of the batteries within the backup battery system.

6. The system of claim 4 , wherein the target current within each charging profile is based on a size of the batteries within the backup battery system.

7. The system of claim 1 , wherein the microcontroller receives a temperature measurement of the backup battery system, obtains a temperature compensation voltage based upon the measured temperature, and updates the register based upon the temperature compensation voltage.

8. The system of claim 7 , wherein the microcontroller receives the temperature measurement from a temperature sensor located within the backup battery system.

9. A building management system, comprising:
a system panel for controlling the building management system including at least one microcontroller;
a backup battery system for powering the system panel; and
a charging system for charging the backup battery system, including an analog power converter that provides an output current at an output voltage to the backup battery system under control of the microcontroller;
wherein the microcontroller controls the output current by updating a register within an output current digital resistor of a current feedback loop of the charging system.

10. A method for a building management system, the method comprising:
a system panel controlling the building management system, the system panel including at least one microcontroller;
a backup battery system powering the system panel; and
a charging system charging the backup battery system, the at least one microcontroller controlling an analog power converter of the charging system to provide an output current at an output voltage to the backup battery system by the microcontroller updating a register within an output voltage digital resistor of a voltage feedback loop of the charging system.

11. The method of claim 10 , further comprising the system panel being a fire control panel of a fire alarm system, the fire alarm system operating as the building management system.

12. The method of claim 10 , further comprising the charging system measuring errors in the output voltage and/or output current, and correcting the errors.

13. The method of claim 10 , further comprising storing one or more charging profiles for the backup battery system, the one or more charging profiles including a target current based on a size of batteries within the backup battery system, the target current defining a maximum value for the output current.

14. The method of claim 10 , further comprising the at least one microcontroller:
controlling a detection circuit including fire sensor devices and a notification circuit including notification devices;
monitoring a power bus that provides a primary source of input power to the life safety system; and
sending notifications to a central station in response to receiving indications of fire from the fire sensor devices.

15. The method of claim 10 , wherein the at least one microcontroller controlling the analog power converter of the charging system to provide the output current at the output voltage to the backup battery system further comprises:
receiving a temperature measurement of the backup battery system;
obtaining a temperature compensation voltage based upon the measured temperature and a target voltage maintained by the microcontroller, and
updating the register within the output voltage digital resistor, the resistor setting being based upon the target voltage offset by the temperature compensation voltage.

16. The method of claim 15 , further comprising the microcontroller obtaining the temperature compensation voltage in response to the microcontroller executing a lookup of the measured temperature from a temperature compensation table maintained by the microcontroller.

17. A method for a building management system, the method comprising:
a system panel controlling the building management system, the system panel including at least one microcontroller;
a backup battery system powering the system panel; and
a charging system charging the backup battery system, the at least one microcontroller controlling an analog power converter of the charging system to provide an output current at an output voltage to the backup battery system by the microcontroller updating a register within an output current digital resistor of a current feedback loop of the charging system.

18. The method of claim 17 , further comprising the microcontroller calculating a resistor setting based on a target current maintained by the microcontroller, the target current defining a maximum value for the output current; and updating the output current digital resistor with the resistor setting.

Assignees

• Tyco Fire & Security Gmbh
• Johnson Controls Fire Prot Lp

Inventors

• Cianfrocco Daniel P
• Gouin Alexandre

Classifications

• H02J7/00

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title

• H02J9/061

  for DC powered loads · CPC title

• H02J9/04

  in which the distribution system is disconnected from the normal source and connected to a standby source · CPC title

• G01R22/00 Primary

  Arrangements for measuring time integral of electric power or current, e.g. electricity meters · CPC title

• H02J7/022

  Electricity · mapped topic