# US 11,309,586 B2 · Power storage device discharge circuit, power storage system, and vehicle equipped with same

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- Number: US 11,309,586 B2
- Document ID: US11309586B2
- Status: Granted
- Kind: B2
- Application number: 17/011,046
- Filed: 2020-09-03
- Published: 2020-12-24
- Granted: 2022-04-19
- Earliest claimed: 2018-03-28
- Assignees: Panasonic Intellectual Property Management Co., Ltd.
- Applicants: Panasonic Intellectual Property Management Co., Ltd.
- Inventors: Hiroaki Tsukamoto; Yohsuke Mitani; Takahiro Kudo; Yoshimitsu Odajima
- Web page: https://patentgrep.com/patent/US11309586B2

## CPC

- H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)}
- B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors}
- B60L 50/40: using propulsion power supplied by capacitors
- B60L 50/60: using power supplied by batteries (in combination with fuel cells B60L50/75)
- B60L 58/22: Balancing the charge of battery modules
- H01M 10/4207: {for several batteries or cells simultaneously or sequentially}
- H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)}
- H01M 10/441: {for several batteries or cells simultaneously or sequentially}
- H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
- H02J 7/02: for charging batteries from AC mains by converters
- H02J 7/34: Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence)
- B60L 58/10: for monitoring or controlling batteries
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- Y02E 60/10: Energy storage using batteries
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
- Y02T 90/14: Plug-in electric vehicles
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A discharge circuit includes a plurality of burden circuits that are electrically connected in parallel to a plurality of power storage units, respectively. Each of the plurality of burden circuits includes (i) a resistor and a switch that are electrically connected in series between both ends of a corresponding one of the plurality of power storage units, and (ii) a control terminal that controls the switch according to a potential of the control terminal. The plurality of burden circuits are electrically connected in series between a positive electrode and a negative electrode. The control terminal of a n+1-th burden circuit from a reference point is electrically connected, via the switch of the n-th burden circuit from the reference point, to a reference point side terminal of a n-th power storage unit from the reference point. The reference point is the positive electrode or the negative electrode.

## Claims

### Claim 1

A discharge circuit for a power storage device including a plurality of power storage units that are electrically connected in series between a positive electrode and a negative electrode, the discharge circuit comprising
a plurality of burden circuits that are electrically connected in parallel to the plurality of power storage units, respectively, wherein:
each of the plurality of burden circuits includes (i) a resistor and a switch that are electrically connected in series between both ends of a corresponding one of the plurality of power storage units, and (ii) a control terminal that controls the switch according to a potential of the control terminal,
the plurality of burden circuits are electrically connected in series between the positive electrode and the negative electrode, and
the control terminal of a n+1-th burden circuit from a reference point among the plurality of burden circuits is electrically connected, via the switch of a n-th burden circuit from the reference point among the plurality of burden circuits, to a reference point side terminal of a n-th power storage unit from the reference point among the plurality of power storage units, the reference point being the positive electrode or the negative electrode.

### Claim 2 (depends on 1)

The discharge circuit for a power storage device according to claim 1, wherein:
in a state that the switch is turned on in all of the plurality of burden circuits,
the resistor of each of the plurality of burden circuits is served as one of a plurality of voltage dividing resistors that are electrically connected in series between the positive electrode and the negative electrode, and
a divided voltage is applied to each of the plurality of power storage units, the divided voltage being obtained from dividing a voltage between the positive electrode and the negative electrode according to the plurality of voltage dividing resistors.

### Claim 3 (depends on 1)

The discharge circuit for a power storage device according to claim 1, wherein the reference point is the positive electrode.

### Claim 4 (depends on 1)

The discharge circuit for a power storage device according to claim 1, wherein the reference point is the negative electrode.

### Claim 5 (depends on 1)

The discharge circuit for a power storage device according to claim 1, the discharge circuit further comprising an abnormality determination section that determines abnormality of the plurality of burden circuits by comparing a state of the switch of a burden circuit closest to the positive electrode among the plurality of burden circuits with a state of the switch of a burden circuit closest to the negative electrode among the plurality of burden circuits.

### Claim 6 (depends on 1)

The discharge circuit for a power storage device according to claim 1, wherein at least one of the plurality of burden circuits further includes a backflow limiting element that limits a current flowing to the control terminal via the resistor.

### Claim 7 (depends on 1)

The discharge circuit for a power storage device according to claim 1, wherein:
the plurality of power storage units include a first power storage unit and a second power storage unit, the first power storage unit including a pair of first cells electrically connected in series, the second power storage unit including a pair of second cells electrically connected in series, and
the first power storage unit and the second power storage unit are directly connected in series between the positive electrode and the negative electrode, the first power storage unit being located close to the reference point.

### Claim 8 (depends on 7)

The discharge circuit for a power storage device according to claim 7, the discharge circuit further comprising an auxiliary resistor and an auxiliary switch that are electrically connected in series between a middle point of the pair of the first cells and a middle point of the pair of the second cells.

### Claim 9 (depends on 1)

A power storage system comprising:
the discharge circuit for a power storage device according to claim 1; and
the power storage device.

### Claim 10 (depends on 9)

A vehicle comprising:
the power storage system according to claim 9; and
a vehicle body provided with the power storage system.