JP-7855931-B2 - Fuel cell system

Inventors

• 楠田 一平
• 安藤 泰明
• 安田 まちよ

Assignees

• 株式会社アイシン

Dates

Publication Date

20260511

Application Date

20220607

Claims (4)

1. A fuel cell system equipped with a fuel cell, A power converter that converts the power output of the fuel cell into electricity that can be supplied to a load and outputs it, A control device that sets a target output power for the power converter and controls the power converter based on an input variable set by feedback control so that the output power of the power converter becomes the target output power, Equipped with, The aforementioned feedback control is a speed-type control that calculates a deviation by subtracting the target output power from the output power, calculates a change amount that includes a proportional term obtained by multiplying the difference between the current value and the previous value of the deviation by a proportional gain, and adds this change amount to the previous value of the manipulated variable to set the manipulated variable. The control device sets the target output power in such a way as to suppress the rate of change of the target output power. Fuel cell system.
2. The control device sets the target output power to the smaller of the power consumed by the load and the power obtained by adding a predetermined value to the output power. The fuel cell system according to claim 1.
3. A fuel cell system equipped with a fuel cell, A power converter that converts the power output of the fuel cell into electricity that can be supplied to a load and outputs it, A control device that sets a target output power of the power converter based on the power consumption of the load, and controls the power converter based on an input variable set by feedback control so that the output power of the power converter becomes the target output power, Equipped with, The aforementioned feedback control is a speed-type control that calculates a deviation by subtracting the target output power from the output power, calculates a change amount that includes a proportional term obtained by multiplying the difference between the current value and the previous value of the deviation by a proportional gain, and adds this change amount to the previous value of the manipulated variable to set the manipulated variable. When the target output power decreases, the control device subtracts a value with a smaller absolute value than the actual value from the current value of the deviation, as the previous value of the deviation. Fuel cell system.
4. The control device sets a value of 0 to a value that is smaller in absolute value than the actual value. The fuel cell system according to claim 3.

Description

This disclosure relates to fuel cell systems. Conventionally, fuel cell systems of this type are known to include a fuel cell that generates electricity using fuel gas and air, and a power converter that converts the fuel cell's output into power that can be supplied to a load. For example, Patent Document 1 describes a system in which feedback control is performed by setting a target output power so that the output power of the power converter corresponds to the power consumed by the load, and in order to protect the fuel cell, the rate of increase in output power is limited. Japanese Patent Application Publication No. 7-57753 This is a schematic diagram showing the general configuration of the fuel cell system 10.This is a block diagram showing an example of the functions of the control device 90.This is an explanatory diagram showing the difference in the rate of increase of output power P depending on whether or not there is an output limit.This is a flowchart showing an example of the target power setting process.This is an explanatory diagram showing an example of the changes in power consumption Pcon, target power Ptag, and output power P in this embodiment.This is an explanatory diagram showing an example of the changes in power consumption Pcon, target power Ptag, and output power P in a comparative example.This is a flowchart showing an example of proportional term calculation processing. Next, embodiments of this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of the fuel cell system 10. As shown in the figure, the fuel cell system 10 of this embodiment includes a power generation module 20 containing a fuel cell stack 21 that generates electricity through an electrochemical reaction between hydrogen in the anode gas and oxygen in the cathode gas; a raw fuel gas supply device 30 that supplies raw fuel gas (e.g., natural gas or LPG) to the power generation module 20 as a raw material for the anode gas; a reformed water supply device 40 that supplies reformed water necessary for reforming the raw fuel gas to the anode gas (steam reforming) to the power generation module 20; an air supply device 50 that supplies air as cathode gas to the power generation module 20 (fuel cell stack 21); a waste heat recovery device 60 that recovers waste heat generated in the power generation module 20; and a control device 90 that controls the entire system. The power generation module 20 includes a fuel cell stack 21, a vaporizer 22, a reformer 23, a combustor 24, and multiple (two) heat exchangers 26 and 27, all housed in an insulated module case 29. The fuel cell stack 21 comprises multiple solid oxide single cells, each having an electrolyte such as zirconium oxide and an anode and cathode that sandwich the electrolyte. An anode gas passage is connected to the anode of each single cell through which anode gas flows. Similarly, a cathode gas passage is connected to the cathode of each single cell through which cathode gas flows. A temperature sensor 112 is installed near the fuel cell stack 21. The temperature sensor 112 detects a temperature correlated with the temperature of the fuel cell stack 21 (stack correlation temperature). The vaporizer 22 and reformer 23 of the power generation module 20 are positioned above the fuel cell stack 21 within the module case 29, with a gap between them. A combustor 24 is also positioned between the fuel cell stack 21 and the vaporizer 22 and reformer 23 to generate the heat necessary for the operation of the fuel cell stack 21 and the reactions in the vaporizer 22 and reformer 23. The vaporizer 22 heats the raw fuel gas from the raw fuel gas supply device 30 and the reformed water from the reformed water supply device 40 using heat from the combustor 24, preheating the raw fuel gas and evaporating the reformed water to generate steam. The raw fuel gas preheated by the vaporizer 22 is mixed with the steam, and this mixed gas flows from the vaporizer 22 into the reformer 23. A temperature sensor 111 is installed near the inlet of the reformer 23 to detect the temperature of the mixed gas flowing into the reformer 23. The reformer 23 contains a reforming catalyst, such as a Ru-based or Ni-based one, and in the presence of heat from the combustor 24, it produces hydrogen gas and carbon monoxide through a reaction (steam reforming reaction) between the reforming catalyst and the mixed gas from the vaporizer 22. Furthermore, the reformer 23 produces hydrogen gas and carbon dioxide through a reaction (carbon monoxide shift reaction) between the carbon monoxide produced in the steam reforming reaction and water vapor. As a result, the reformer 23 produces an anode gas containing hydrogen, carbon monoxide, carbon dioxide, water vapor, and unreformed raw fuel gas. The anode gas produced by the reformer 23 flows through the anode gas piping 71 into the anode gas passage of each single cell and is supplied to the ano