# US 11,028,492 B2 · Electrolytic system, electrolytic control circuit, and control method for electrolytic system

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- Number: US 11,028,492 B2
- Document ID: US11028492B2
- Status: Granted
- Kind: B2
- Application number: 16/152,447
- Filed: 2018-10-05
- Published: 2019-05-02
- Granted: 2021-06-08
- Earliest claimed: 2017-11-02
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Yu Yonezawa; Hiroshi Nakao; Yoshiyasu Nakashima; Daiji Yamashita
- Web page: https://patentgrep.com/patent/US11028492B2

## CPC

- C25B 15/02: Process control or regulation
- C25B 1/04: by electrolysis of water
- H02J 3/38: Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel
- H02J 3/466: Scheduling or selectively controlling the operation of the generators or sources, e.g. connecting or disconnecting generators to meet a demand
- H02M 3/33507: {with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence)}
- Y02E 10/56: Power conversion systems, e.g. maximum power point trackers
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An electrolytic system includes, a power generator that outputs a first DC power, a plurality of converters each of which converts the first DC power into a second DC power according to a target duty ratio, and outputs voltage information and current information of the second DC power, a plurality of electrolyzers each of which receives the second DC power output from each of the plurality of converters and generates a gas, a control circuit that outputs control information by which the first DC power approaches a maximum power, based on a voltage value and a current value of the first DC power, and a selection circuit that outputs the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information and the voltage information and the current information.

## Claims

### Claim 1

An electrolytic system comprising:
a power generator configured to output a generated first DC power;
a plurality of converters each of the plurality of converters is configured to:
convert the first DC power output by the power generator into a second DC power according to a received target duty ratio, and
output voltage information of the second DC power and current information of the second DC power;
a plurality of electrolyzers each of the plurality of electrolyzers is configure to:
receive the second DC power output from each of the plurality of converters, and generate a gas;
a control circuit configured to execute control processing every time a start signal is inputted, the control processing including:
obtain a measurement value of the first DC power;
output control information by which the first DC power output by the power generator approaches a maximum power, based on the obtained measurement value of the first DC power;
in response to detecting that the measurement value at a present time is larger than the measurement value at a previous time, output the control information configured to cause a selection circuit to change the target duty ratio in a same direction as a changing direction at the previous time; and
in response to detecting that the measurement value at a present time is equal to or smaller than the measurement value at the previous time, output the control information configured to cause the selection circuit to change the target duty ratio in an opposite direction as the changing direction at the previous time; and the selection circuit configured to output the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information output by the control circuit and the voltage information and the current information output by each of the plurality of converters.

### Claim 2 (depends on 1)

The electrolytic system according to claim 1, wherein the selection circuit selects a converter for which a duty ratio is to be changed by a specified change amount, among the plurality of converters.

### Claim 3 (depends on 1)

The electrolytic system according to claim 1, wherein the selection circuit selects a converter for which a duty ratio is to be changed, among the plurality of converters, according to a parameter calculated based on the voltage information and the current information output by each of the plurality of converters.

### Claim 4 (depends on 1)

The electrolytic system according to claim 1, wherein the control information is a control target value corresponding to a value of a change amount Δx of a duty ratio x.

### Claim 5 (depends on 1)

The electrolytic system according to claim 1, wherein the selection circuit selects an electrolyzer having a highest use priority among stopped electrolyzers when increasing a number of electrolyzers to be operated, and selects an electrolyzer having a lowest use priority among operating electrolyzers when decreasing a number of electrolyzers to be operated.

### Claim 6 (depends on 1)

The electrolytic system according to claim 1, wherein the selection circuit outputs the selection signal according to an attribute of each of the plurality of electrolyzers.

### Claim 7 (depends on 6)

The electrolytic system according to claim 6, wherein the attribute is a resistance value, and the selection circuit outputs the selection signal such that an electrolyzer in which the resistance value is smaller, among the plurality of electrolyzers, is preferentially operated.

### Claim 8 (depends on 6)

The electrolytic system according to claim 6, wherein the attribute is an operating time, and the selection circuit outputs the selection signal such that an electrolyzer in which the operating time is shorter, among the plurality of electrolyzers, is preferentially operated.

### Claim 9 (depends on 7)

The electrolytic system according to claim 7, wherein the selection circuit corrects the target duty ratio according to the resistance value of each of the plurality of electrolyzers.

### Claim 10 (depends on 7)

The electrolytic system according to claim 7, wherein the selection circuit generates an alarm corresponding to the electrolyzer having the resistance value exceeding a threshold value, among the plurality of electrolyzers.

### Claim 11 (depends on 7)

The electrolytic system according to claim 7, wherein the selection circuit stops the electrolyzer having the resistance value exceeding a threshold value, among the plurality of electrolyzers.

### Claim 12

An electrolytic control circuit that controls, a plurality of converters each of the plurality of converters is configured to convert a first DC power received from a power generator into a second DC power according to a received target duty ratio, and output voltage information of the second DC power and current information of the second DC power, and a plurality of electrolyzers each of the plurality of electrolyzers is configured to receive the second DC power output from each of the plurality of converters and generate a gas, the electrolytic control circuit comprising:
a control circuit configured to execute control processing every time a start signal is inputted, the control processing including:
obtain a measurement value of the first DC power;
output control information by which the first DC power output by the power generator approaches a maximum power, based on the obtained measurement value of the first DC power;
in response to detecting that the measurement value at a present time is larger than the measurement value at a previous time, output the control information configured to cause a selection circuit to change the target duty ratio in a same direction as a changing direction at the previous time; and
in response to detecting that the measurement value at a present time is equal to or smaller than the measurement value at the previous time, output the control information configured to cause the selection circuit to change the target duty ratio in an opposite direction as the changing direction at the previous time; and
the selection circuit configured to output the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information output by the control circuit and the voltage information and the current information output by each of the plurality of converters.

### Claim 13 (depends on 12)

The electrolytic control circuit according to claim 12, wherein the selection circuit selects a converter for which a duty ratio is to be changed by a specified change amount, among the plurality of converters.

### Claim 14 (depends on 12)

The electrolytic control circuit according to claim 12, wherein the selection circuit selects a converter for which a duty ratio is to be changed, among the plurality of converters, according to a parameter calculated based on the voltage information and the current information output by each of the plurality of converters.

### Claim 15

A control method for electrolytic system including a power generator, a plurality of converters, a plurality of electrolyzers, a control circuit, and a selection circuit, the method comprising:
converting, by each of the plurality of converters, a first DC power output by the power generator into a second DC power according to a received target duty ratio;
outputting, by each of the plurality of converters, voltage information of the second DC power and current information of the second DC power;
receiving, by each of the plurality of electrolyzers, the second DC power output from each of the plurality of converters;
generating a gas, by each of the plurality of electrolyzers;
executing, by the control circuit, control processing every time a start signal is inputted, the control processing including:
obtaining a measurement value of the first DC power;
outputting, by the control circuit, control information by which the first DC power output by the power generator approaches a maximum power, based on the obtained measurement value of the first DC power;
in response to detecting that the measurement value at a present time is larger than the measurement value at a previous time, outputting the control information configured to cause the selection circuit to change the target duty ratio in a same direction as a changing direction at the previous time; and
in response to detecting that the measurement value at a present time is equal to or smaller than the measurement value at the previous time, outputting the control information configured to cause the selection circuit to change the target duty ratio in an opposite direction as the changing direction at the previous time; and
outputting, by the selection circuit, the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information output by the control circuit, the voltage information and the current information output by each of the plurality of converters.

### Claim 16 (depends on 15)

The control method according to claim 15, wherein the selection circuit selects a converter for which a duty ratio is to be changed by a specified change amount, among the plurality of converters.

### Claim 17 (depends on 15)

The control method according to claim 15, wherein the selection circuit selects a converter for which a duty ratio is to be changed, among the plurality of converters, according to a parameter calculated based on the voltage information and the current information output by each of the plurality of converters.