Abstract: In response to connection of a vehicle with an external power supply, a plug ECU (PLG-ECU) performs a first charging operation of controlling a charger using a target value which is set to a state of charge lower than a predetermined full state of charge, until the state of charge of a power storage device reaches the target value. After the state of charge reaches the target value, the PLG-ECU stops charging of the power storage device, and restarts charging of the power storage device so that the state of charge reaches the predetermined full state of charge at a scheduled time to end charging which is specified through the use of an input unit.

Abstract: A fuel cell system is provided in which the concentration increase of discharged fuel gas is inhibited even when abnormality is detected in a discharge unit. A fuel cell system in which a fuel gas discharged from a discharge unit (SV5) is diluted with an oxidizing gas (14) and discharged comprises an abnormality detection unit (205) for detecting an operation abnormality of the discharge unit (SV5), and a change unit (206, 207) for changing the supplied quantity of the oxidizing gas when an abnormality of the discharge unit (SV5) is detected, and the concentration of the diluted (14) and discharged fuel gas is changed and inhibited by changing the supplied quantity of the oxidizing gas.

Abstract: Weld of a relay provided on an electric power supply path can be suppressed. When a fuel cell system starts, a controller sets an output voltage of a Bat converter at an open circuit voltage of a battery and sets an output voltage of a FC converter at an open circuit voltage of a fuel cell. When the output voltage of the FC converter is lower than the output voltage of the Bat converter, the controller controls to boost the output voltage of the FC converter to the output voltage of the Bat converter. On the other hand, when the output voltage of the FC converter is the output voltage of the Bat converter or more, the controller controls to boost the output voltage of the Bat converter to the output voltage of the FC converter. When the output voltage difference between the FC converter and the Bat converter is a predetermined value or less capable of turning the FC relays ON without causing welding of the FC relays, the controller turns the FC relays ON.

Abstract: A failure diagnostic device for accurately determining a failure of a discharge valve. A failure diagnostic device (50) serves to perform failure diagnostic of a discharge valve (62) installed in a discharge flow channel (32) of an anode discharge gas that is discharged from a fuel cell stack (20). The device comprises a detection unit (70) for detecting a status quantity of the anode discharge gas between a discharge port (27) for the anode discharge gas of the fuel cells tack (2) and the discharge valve (62) and a determination unit (51) for determining a failure of the discharge valve (62) based on the status quantity of the anode discharge gas detected by the detection unit (70) and a failure determination quantity corresponding to the operating state of the fuel cell stack (20).

Abstract: The object of this invention is to provide a fuel supply system capable of reducing the quantity of a fuel to be discharged from a plurality of fuel tanks connected in parallel is provided. The fuel supply system includes a plurality of the fuel tanks for storing a fuel, on-off valves provided individually for the fuel tanks, and a control unit which controls the opening and closing of the on-off valves. The control unit changes the number of the on-off valves to be simultaneously opened according to a situation. The control unit may reduce the number of the on-off valves to be simultaneously opened after a failure is detected or at the time of maintenance of the fuel supply system.

Abstract: In response to connection of a vehicle with an external power supply, a PLG-ECU performs a first charging operation of controlling a charger using a target value which is set to a state of charge lower than a predetermined full state of charge, until the state of charge of a power storage device reaches the target value. After the state of charge reaches the target value, the PLG-ECU stops charging of the power storage device, and restarts charging of the power storage device so that the state of charge reaches the predetermined full state of charge at a scheduled time to end charging which is specified through the use of an input unit.

Abstract: Even if a failure occurs in a bypass valve during low-efficiency power generation, the occurrence of an excessive stoichiometry ratio in a fuel cell can be prevented. An output from a pressure sensor or a current sensor is monitored by a control device, and when a failure associated with a closed-valve malfunction of the bypass valve occurs, the degree of opening of the pressure regulating valve is increased to increase an amount of cathode-off gas exhaust, and a revolution speed of an air compressor is reduced to an amount of air discharged by the air compressor, thereby preventing an excessive stoichiometry ratio in the fuel cell.

Abstract: A gas level display controller sequentially calculates a mass of a compressed gas stored in a tank and makes a comparison between a first calculated value obtained at a first timing and a second calculated value obtained at a second timing later than the first timing. When the second calculated value is smaller than the first calculated value, the gas level display controller makes the remaining amount of the compressed gas in the tank displayed on a predetermined display device, based on the second calculated value. When the second calculated value is not smaller than the first calculated value, the gas level display controller makes the remaining amount of the compressed gas in the tank displayed on the predetermined display device, based on the first calculated value.

Abstract: In a hydrogen tank, discharge of a hydrogen gas may cause lowering of the temperature to a value at which it is assumed that disconnection has occurred in a thermistor. A temperature detection system for the hydrogen tank estimates the possibility that the temperature of the hydrogen tank is below this temperature value, according to the ambient temperature and the internal pressure. Only when there is no possibility that the temperature is below the value, disconnection is judged to have occurred.

Abstract: A fuel cell system of the invention includes, a fuel cell, a water reservoir configured to accumulate water discharged from the fuel cells, and a status estimator configured to estimate a status of the water reservoir based on a stated of the fuel cell.

Abstract: Weld of a relay provided on an electric power supply path can be suppressed. When a fuel cell system starts, a controller sets an output voltage of a Bat converter at an open circuit voltage of a battery and sets an output voltage of a FC converter at an open circuit voltage of a fuel cell. When the output voltage of the FC converter is lower than the output voltage of the Bat converter, the controller controls to boost the output voltage of the FC converter to the output voltage of the Bat converter. On the other hand, when the output voltage of the FC converter is the output voltage of the Bat converter or more, the controller controls to boost the output voltage of the Bat converter to the output voltage of the FC converter. When the output voltage difference between the FC converter and the Bat converter is a predetermined value or less capable of turning the FC relays ON without causing welding of the FC relays, the controller turns the FC relays ON.

Abstract: A fuel battery system comprises a fuel battery stack, a hydrogen supply system for supplying hydrogen from a hydrogen tank, an oxidant gas supply system for supplying air serving as an oxidant by an air compressor, an electrical system including an impedance measuring unit for measuring the impedance of a fuel battery, a DC/DC converter for converting generated electric power, a secondary battery for storing electric power, and so on, and a drive system for driving a vehicle. When the power generation is stopped by turning off an ignition switch in the state in which the power generation is suspended in an intermittent operation, the impedance measuring unit measures the impedance after the supply of air is stabilized to avoid the transient state of the fuel battery cell caused by a delay in air supply.

Abstract: A fuel battery system comprises a fuel battery stack, a hydrogen supply system for supplying hydrogen from a hydrogen tank, an oxidant gas supply system for supplying air serving as an oxidant by an air compressor, an electrical system including an impedance measuring unit for measuring the impedance of a fuel battery, a DC/DC converter for converting generated electric power, a secondary battery for storing electric power, and so on, and a drive system for driving a vehicle. When the power generation is stopped by turning off an ignition switch in the state in which the power generation is suspended in an intermittent operation, the impedance measuring unit measures the impedance after the supply of air is stabilized to avoid the transient state of the fuel battery cell caused by a delay in air supply.

Abstract: Even if a failure occurs in a bypass valve during low-efficiency power generation, the occurrence of an excessive stoichiometry ratio in a fuel cell can be prevented. An output from a pressure sensor or a current sensor is monitored by a control device, and when a failure associated with a closed-valve malfunction of the bypass valve occurs, the degree of opening of the pressure regulating valve is increased to increase an amount of cathode-off gas exhaust, and a revolution speed of an air compressor is reduced to an amount of air discharged by the air compressor, thereby preventing an excessive stoichiometry ratio in the fuel cell.

Abstract: At startup of the fuel cell system, following successful completion of feeding of reactant gases (a fuel gas and an oxidant gas) to the fuel cell, the open circuit voltage OCV of the fuel cell is measured, and based on whether the open circuit voltage of the fuel cell is equal to or greater than a prescribed voltage OCVth, it is decided whether the fuel cell is experiencing a generation malfunction. The decision as to whether feeding of the reactant gases to the fuel cell has successfully completed will be made, for example, on the basis of whether feed pressure of the reactant gases to the fuel cell is at or above prescribed pressure. Thus, generation malfunction in the fuel cell can be correctly diagnosed at startup of the fuel cell system.

Abstract: A gas level display controller sequentially calculates a mass of a compressed gas stored in a tank and makes a comparison between a first calculated value obtained at a first timing and a second calculated value obtained at a second timing later than the first timing. When the second calculated value is smaller than the first calculated value, the gas level display controller makes the remaining amount of the compressed gas in the tank displayed on a predetermined display device, based on the second calculated value. When the second calculated value is not smaller than the first calculated value, the gas level display controller makes the remaining amount of the compressed gas in the tank displayed on the predetermined display device, based on the first calculated value.

Abstract: In a hydrogen tank, discharge of a hydrogen gas may cause lowering of the temperature to a value at which it is assumed that disconnection has occurred in a thermistor. A temperature detection system for the hydrogen tank estimates the possibility that the temperature of the hydrogen tank is below this temperature value, according to the ambient temperature and the internal pressure. Only when there is no possibility that the temperature is below the value, disconnection is judged to have occurred.

Abstract: A purging apparatus for a fuel cell system according to the present invention comprises a steam supply pass 18 and an air supply pass 19. A purging method for the fuel cell system according to the present invention comprises, at a time of causing a fuel reformer 12, a fuel cell body 1 and a fuel supply line 13 to carry out the purging operation, first carrying out the purging operation by steam, and then carrying out the purging operation by air. According to such a structure, there can be provided the purging apparatus for the fuel cell system and the method therefor, which have an easy structure and an easy operation, and enables combustible gas and condensed water remaining in the system to be removed in a reliable manner.

Abstract: A fuel cell system of the invention includes, a fuel cell, a water reservoir configured to accumulate water discharged from the fuel cells, and a status estimator configured to estimate a status of the water reservoir based on a stated of the fuel cell.

Abstract: The object of this invention is to provide a fuel supply system capable of reducing the quantity of a fuel to be discharged from a plurality of fuel tanks connected in parallel is provided. The fuel supply system includes a plurality of the fuel tanks for storing a fuel, on-off valves provided individually for the fuel tanks, and a control unit which controls the opening and closing of the on-off valves. The control unit changes the number of the on-off valves to be simultaneously opened according to a situation. The control unit may reduce the number of the on-off valves to be simultaneously opened after a failure is detected or at the time of maintenance of the fuel supply system.