A catalyst deterioration suppression device includes: a first device obtaining a fuel cell voltage V (=catalyst voltage V.sub.cat) as a variable to estimate a response speed (time constant τ) at which a coverage ratio of an oxide film of catalyst particles contained in a fuel cell cathode changes; a second device reading out a time constant τ.sub.t corresponding to the voltage V at a current time t from a pre-made map A representing a relationship between the voltage V and the time constant τ and corresponding to the catalyst particles; a third device generating a continuous-time type dynamic filter F(s, τ) by using the time constant τ.sub.t and converting the continuous-time type dynamic filter F(s, τ) to a discrete-time type dynamic filter F(z, τ); and a fourth device inputting a target voltage Vr to the discrete-time type dynamic filter F(z, τ) and outputting a corrected target voltage V.sub.r-fil.

A method for controlling a fuel cell system having a hydrogen fuel injector/ejector and a control system, includes determining a hydrogen fuel consumption rate associated with a selected power level at steady state, determining a modeled hydrogen fuel flow rate associated with the selected power level and the injector/ejector, determining a modeled effective flow area associated with the injector/ejector, determining a true effective flow area of the injector/ejector, and using the effective flow area to calculate or adjust a command signal, an estimation or an estimation error of at least one of a hydrogen fuel flow rate, an anode leak rate and an anode exhaust valve flow rate.

A fuel cell system includes a plurality of fuel cells and a control device that controls an operation state of each fuel cell. The control device has a command receiver that acquires an output command showing a total output power which should be generated by the fuel cell system, a first determiner that determines the number of fuel cells which should be operated in the normal operation mode, and an operation state manager that determines the operation state of each fuel cell. Based on the output command, the operation state manager changes the operation state of at least one of the fuel cells which are being operated in the normal operation mode to the standby operation mode, or changes the operation state of at least one of the fuel cells which are being operated in the standby operation mode to the normal operation mode.

A fuel cell system includes a plurality of fuel cells and a control device that controls an operation state of each fuel cell. The control device has a command receiver that acquires an output command showing a total output power which should be generated by the fuel cell system, a first determiner that determines the number of fuel cells which should be operated in the normal operation mode, and an operation state manager that determines the operation state of each fuel cell. Based on the output command, the operation state manager changes the operation state of at least one of the fuel cells which are being operated in the normal operation mode to the standby operation mode, or changes the operation state of at least one of the fuel cells which are being operated in the standby operation mode to the normal operation mode.

A fuel cell system includes fuel cell modules connected in parallel and each including fuel cell stacks connected in series. A tester includes: an output power acquirer that acquires an output power value for each fuel cell stack; a deterioration estimator that estimates a degree of future deterioration for each fuel cell stack; and a future output power estimator that estimates, for each fuel cell stack, a future output power value, which is a value of power that is likely to be outputted after a specific period of time has passed, based on the degree of future deterioration estimated by the deterioration estimator. The fuel cell stack combining method includes determining combinations of the fuel cell stacks based on differences in the output power value between the fuel cell stacks and differences in the future output power value between the fuel cell stacks.

A method of controlling a fuel battery system of the present disclosure is a method of controlling a fuel battery system, including a measurement process in which a power generation voltage at a predetermined current density of a fuel battery cell is measured, a first calculation process in which a poisoning rate of an electrode catalyst at the power generation voltage measured in the measurement process is calculated from a predetermined relationship between the power generation voltage at the predetermined current density and the poisoning rate of the electrode catalyst of the fuel battery cell, and a second calculation process in which a generation rate of hydrogen peroxide at the poisoning rate of the electrode catalyst calculated in the first calculation process is calculated from a predetermined relationship between the poisoning rate of the electrode catalyst and the generation rate of hydrogen peroxide of the fuel battery cell.

A method of controlling a fuel battery system of the present disclosure is a method of controlling a fuel battery system, including a measurement process in which a power generation voltage at a predetermined current density of a fuel battery cell is measured, a first calculation process in which a poisoning rate of an electrode catalyst at the power generation voltage measured in the measurement process is calculated from a predetermined relationship between the power generation voltage at the predetermined current density and the poisoning rate of the electrode catalyst of the fuel battery cell, and a second calculation process in which a generation rate of hydrogen peroxide at the poisoning rate of the electrode catalyst calculated in the first calculation process is calculated from a predetermined relationship between the poisoning rate of the electrode catalyst and the generation rate of hydrogen peroxide of the fuel battery cell.

To provide an electrical power system and an electrical power control device that make it possible to improve fuel efficiency compared to that conventionally possible. An electrical power system according to an embodiment includes fuel cells at a count of n, n representing an integer of 2 or greater, and a controller. The fuel cells are each configured to generate electrical power through electrochemical reactions. The controller is configured to set, based on a required output required in accordance with electrical power to be consumed by a load, an operation mode for each of the fuel cells to one mode determined from a plurality of modes including a first electrical power generation mode under which starting and stopping of generation of electrical power are repeated, a second electrical power generation mode under which generation of electrical power continues, and a stop mode under which generation of electrical power is stopped.

A control method for a fuel cell stop mode is provided. The method includes measuring an air flow rate supplied to a fuel cell stack and when a fuel cell stop mode is entered, determining an oxygen distribution state between cells included in the fuel cell stack based on the measured air flow rate. Air supply is then supplied to the fuel cell stack or the air supply to the fuel cell stack is interrupted based on the determined oxygen distribution state.

A control method for a fuel cell stop mode is provided. The method includes measuring an air flow rate supplied to a fuel cell stack and when a fuel cell stop mode is entered, determining an oxygen distribution state between cells included in the fuel cell stack based on the measured air flow rate. Air supply is then supplied to the fuel cell stack or the air supply to the fuel cell stack is interrupted based on the determined oxygen distribution state.