Apparatus for balancing battery power

Patent metadata

Field	Value
Publication number	US-10027135-B2
Application number	US-201615262781-A
Country	US
Kind code	B2
Filing date	Sep 12, 2016
Priority date	Sep 30, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

An apparatus for balancing battery power can include: a battery selection circuit coupled to N batteries, where the battery selection circuit is configured to couple one of the N batteries to a charge and discharge port, where N is an integer greater than 1; a bi-directional power converter having a first terminal coupled to the charge and discharge port, and a second terminal coupled to a storage capacitor; N detection circuits corresponding to the N batteries, where each of the N detection circuits is configured to detect a state of a corresponding of the N batteries; and a control circuit configured to control the battery selection circuit to couple a selected battery to the charge and discharge port, and to charge or discharge the selected battery through the bi-directional power converter to maintain a voltage of the storage capacitor to be within a predetermined range.

First claim

What is claimed is:

1. An apparatus for balancing battery power, the apparatus comprising:
a) a battery selection circuit coupled to N batteries, wherein said battery selection circuit is configured to couple one of said N batteries to a charge and discharge port, wherein N is an integer greater than 1;
b) a bi-directional power converter having a first terminal coupled to said charge and discharge port, and a second terminal coupled to a storage capacitor;
c) N detection circuits corresponding to said N batteries, wherein each of said N detection circuits is configured to detect a state of a corresponding of said N batteries; and
d) a control circuit configured to control said battery selection circuit to couple a selected battery to said charge and discharge port, and to charge or discharge said selected battery through said bi-directional power converter to maintain a voltage of said storage capacitor to be within a predetermined range.

2. The apparatus of claim 1 , wherein said battery selection circuit comprises:
a) N first switches controlled by said control circuit, wherein each of said first switches comprises a first terminal coupled to an anode of a corresponding battery, and a second terminal coupled to a first terminal of said charge and discharge port; and
b) N second switches controlled by said control circuit, wherein each of said second switches comprises a first terminal coupled to a cathode of a corresponding battery, and a second terminal coupled to a second terminal of said charge and discharge port.

3. The apparatus of claim 2 , wherein:
a) each of the 2 nd to the N th first switches comprises two MOS transistors that are reversely coupled in series; and
b) each of the 1 st to the (N-1) th second switches comprises two MOS transistors that are reversely coupled in series.

4. The apparatus of claim 1 , wherein said control circuit comprises:
a) a current detection circuit configured to obtain a current detection signal by detecting a current flowing through one terminal of said charge and discharge port;
b) a voltage hysteresis comparator configured to generate a voltage status signal by detecting said voltage of said storage capacitor, wherein said voltage status signal is switched to a first state when said voltage of said storage capacitor is decreased to be less than a lower threshold, and is switched to a second state when said voltage of said storage capacitor is increased to be greater than a upper threshold;
c) a first controller configured to control said battery selection circuit to couple said selected battery to said charge and discharge port according to said state of said battery, and to generate first and second current reference signals, wherein said first current reference signal represents a discharge current reference of said selected battery, and said second current reference signal represents a charge current reference of said selected battery; and
d) a second controller configured to control said bi-directional power converter according to said current detection signal, said first and second current reference signals, and said voltage status signal.

5. The apparatus of claim 4 , wherein said second controller is configured to control said bi-directional power converter by enabling said current detection signal to be within a predetermined range of said first current reference signal when said voltage status signal is in said first state, and by enabling said current detection signal to be within a predetermined range of said second current reference signal when said voltage status signal is in said second state.

6. The apparatus of claim 1 , wherein said control circuit comprises:
a) a current detection circuit configured to obtain a current detection signal by detecting a current flowing through one terminal of said charge and discharge port;
b) a voltage hysteresis comparator configured to generate a voltage status signal by detecting said voltage of said storage capacitor, wherein said voltage status signal is switched to a first state when said voltage of said storage capacitor is decreased to be less than a lower threshold, and is switched to a second state when said voltage of said storage capacitor is increased to be greater than an upper threshold;
c) a first controller configured to control said battery selection circuit to couple said selected battery to said charge and discharge port according to said state of said battery, and to output a current reference signal according to said voltage status signal; and
d) a second controller configured to control said bi-directional power converter by enabling said current detection signal to be within a predetermined range of said current reference signal.

7. The apparatus of claim 6 , wherein said first controller is configured to output a current reference signal of a first value when said voltage detection signal is in said first state, and to output a current reference signal of a second value when said voltage detection signal is in said second state, wherein said first value is a discharge current reference of said selected battery, and said second value is a charge current reference of said selected battery.

8. The apparatus of claim 4 , wherein said first controller is configured to alternatively couple batteries to be charged and discharged to said charge and discharge port.

9. The apparatus of claim 4 , wherein said first controller is configured to control said battery selection circuit to switch batteries being coupled to said charge and discharge port when said current detection signal crosses zero.

10. The apparatus of claim 1 , further comprising:
a) a shunting circuit coupled in parallel to said storage capacitor, wherein said shunting circuit is configured to controllably discharge said storage capacitor; and
b) said control circuit being configured to control said shunting circuit to discharge said storage capacitor when the state of charge or the state of a charging current of said selected battery satisfies a shunting condition.

11. The apparatus of claim 10 , wherein said shunting circuit comprises a resistor and a switch that are coupled in series.

12. The apparatus of claim 1 , further comprising a clamping circuit coupled to said charge and discharge port.

Assignees

• Silergy Semiconductor Technology Hangzhou Ltd

Inventors

• Shen Zhiyuan

Classifications

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J7/56

  Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters · CPC title

• H02J7/80 Primary

  including monitoring or indicating arrangements · CPC title

• H02J7/0016 Primary

  Electricity · mapped topic