Solid oxide fuel cell system

Patent metadata

Field	Value
Publication number	US-9515335-B2
Application number	US-201114347990-A
Country	US
Kind code	B2
Filing date	Sep 29, 2011
Priority date	Sep 29, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The invention is to provide a solid oxide fuel cell system including: a fuel cell module, a fuel flow regulator unit, a first power demand detection device, a control section for controlling a fuel supply amount and setting the current value extractable from the fuel cell module, an inverter for extracting current in a range not exceeding the extractable current value, and a power state detecting sensor for detecting actual extracted current value; whereby if actual extracted current value declines, then under circumstances where power demand begins to rise in a state of extra margin in the fuel supply amount after the controller suddenly decreases the extractable current value and suddenly reduces the electrical collector, the controller increases the extractable current value at a high current rise rate of change.

First claim

The invention claimed is:

1. A solid oxide fuel cell system for generating electrical power variable in response to power demand, comprising:
a fuel cell module configured to generate electricity by reaction of fuel;
a fuel supply device configured to supply the fuel to the fuel cell module;
a power demand detection device configured to detect the power demand;
an inverter operable to extract electrical current from the fuel cell module and output the extracted current in alternating form;
a controller programmed to
(i) from the power demand detected by the power demand detection device, generate a target current signal, indicative of a target amount of fuel to be supplied to the fuel cell module, which directs the fuel supply device to supply the target amount of fuel to the fuel cell module so that the fuel cell module generates electricity sufficient to follow transitions of the power demand, and
(ii) from the power demand detected by the power demand detection device, generate an extractable current signal, indicative of a maximum current value extractable from the fuel cell module, which directs inverter to extract electrical current from the fuel cell module to an extent not to exceed the maximum extractable current value;

an extracted current detection device configured to generate an actual current signal indicative of a value of current extracted from the fuel cell module by the inverter,
wherein the controller is further programmed to vary the extractable current signal to increase the maximum extractable current value at different increase rates in such a manner that the maximum extractable current value is increased at a higher increase rate when a degree to which the target current signal is higher than the actual current signal is greater so as to allow the inverter to extract more current from the fuel cell module when the degree to which the target current signal is higher than the actual current signal is greater.

2. The solid oxide fuel cell system according to claim 1 , wherein the controller is programmed to change the target current signal to decrease the amount of fuel to be supplied to the fuel cell module when either of the following conditions (a)+(b) or (a)+(c) is met:
(a) the degree to which the target current signal is higher than the actual current signal is greater than a predetermined degree;
(b) condition (a) stays for a predetermined period of time; and
(c) while condition (a) is met, the degree to which the target current signal is higher than the actual current signal increases within the predetermined period of time.

3. The solid oxide fuel cell system according to claim 2 , wherein the controller is programmed to change the extractable current signal to decrease the maximum extractable current value so that the inverter is allowed to extract less current from the fuel cell module when the extractable current signal is higher than the actual current signal by a predetermined threshold or more.

4. The solid oxide fuel cell system according to claim 3 , wherein the controller is programmed to decrease the maximum extractable current value to the value of current being extracted from the fuel cell module by the inverter.

5. The solid oxide fuel cell system according to claim 2 , wherein the controller is programmed to change the extractable current signal to increase the maximum extractable current value so that the inverter is allowed to extract more current from the fuel cell module when the following conditions (d)+(e) are met:
(d) the degree to which the target current signal is higher than the actual current signal is greater than the predetermined degree; and
(e) while condition (d) is met, the power demand detected by the power demand detection device starts to increase within the predetermined period of time.

Assignees

• Otsuka Toshiharu
• Tsuchiya Katsuhisa
• Shigezumi Tsukasa
• Ooe Toshiharu
• Nakano Kiyotaka
• Matsuo Takuya
• Toto Ltd

Inventors

• Otsuka Toshiharu
• Tsuchiya Katsuhisa
• Shigezumi Tsukasa
• Ooe Toshiharu
• Nakano Kiyotaka
• Matsuo Takuya

Classifications

• H01M8/243

  Grouping of unit cells of tubular or cylindrical configuration · CPC title

• H01M8/0491 Primary

  of fuel cell stacks · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M8/04992 Primary

  characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence · CPC title

• H01M8/04626

  of auxiliary devices, e.g. batteries, capacitors · CPC title