Abstract: To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein the controller controls ON and OFF of the switches of n phases; wherein the controller operates the switches of the n phases at different phases, and the controller operates the switches of the n phases at the same duty ratio; wherein the controller operates the switches of the n phases at different duty ratios, when the controller determines that a specific condition is met; and wherein the controller measures the AC impedance of the fuel cell from the current waveform and voltage waveform of the fuel cell.

Abstract: A power supply control apparatus includes a switching control device configured to switch each of switching elements of a power converter between an on state and an off state alternately, and a discharge control device configured to, when residual charge of the fuel cell is discharged, control a gas supply unit such that oxidant gas is not supplied to the fuel cell, in a first period, control the switching control device such that an on time during which at least one switching element is maintained in the on state is longer than the on time during an operation of the fuel cell and the at least one switching element is switched between the on state and the off state alternately, and, in a second period subsequent to the first period, control the switching control device such that the at least one switching element continues to maintain the on state.

Abstract: To provide a voltage converter configured to suppress individual variation in voltage conversion ratio and configured to achieve a high voltage conversion ratio. A voltage converter comprising a reactor, a switching element, a diode, a current sensor, and a controller, wherein the controller detects a current value of the reactor several times in a switching period; wherein the controller calculates an estimated execution ON time length from a transition of a current value of the reactor detected in the switching period; wherein the controller calculates a difference between the estimated execution ON time length and a command ON time length instructed by the controller; and wherein, by using the difference, the controller corrects the command ON time length of the time when performing any of subsequent ON commands in a range not exceeding a predetermined command ON time upper limit value.

Abstract: A power supply unit includes a power supply and a converter. The converter performs operation selected from the group consisting of boosting and stepping down of an output voltage of the power supply; and includes a reactor in which n-phase coils are magnetically coupled to each other, n-phase switches, and a control unit. The control unit controls duty cycles of the n-phase switches; monitors a current value flowing through the n-phase coils; and performs phase switching control when the control unit determines that an operation condition described below is satisfied, the phase switching control being control in which the control unit performs phase switching from in phase to out of phase in the case where the n-phase switches are being driven in phase and performs phase switching from out of phase to in phase in the case where the n-phase switches are being driven out of phase.

Abstract: To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein a controller controls ON and OFF of switches of n phases; wherein the controller monitors current values of coils; the controller operates the switches of the n phases at different phases; wherein the controller operates duty ratios of the switches of the n phases with periodically increasing and decreasing them, and the controller measures an AC impedance of a fuel cell from a current waveform of and a voltage waveform of the fuel cell; and wherein, when the controller determines that a predetermined condition 1 is met, the controller makes amplitudes which increase and decrease the duty ratios large compared to other operating conditions.

Abstract: A structure equipped with a fuel cell system, wherein the structure comprises: a skirt configured to form an accumulation space between a bottom of the structure and the ground, an air supplier configured to supply off-gas, which is discharged from the fuel cell system, to at least one space selected from the group consisting of the accumulation space and an internal space of the skirt, and a pressure discharger configured to discharge pressure accumulated in the accumulation space to outside of the skirt from a lower end of the skirt, and wherein lift is imparted to the structure by supplying a predetermined amount of the off-gas from the air supplier to at least one space selected from the group consisting of the accumulation space and the internal space of the skirt.

Abstract: To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein the controller controls ON and OFF of the switches of n phases; wherein the controller operates the switches of the n phases at different phases, and the controller operates the switches of the n phases at the same duty ratio; wherein the controller operates the switches of the n phases at the same phase, when the controller determines that a specific condition is met; and wherein the controller measures the AC impedance of the fuel cell from the current waveform and voltage waveform of the fuel cell.

Abstract: To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein the controller controls ON and OFF of the switches of n phases; wherein the controller operates the switches of the n phases at different phases, and the controller operates the switches of the n phases at the same duty ratio; wherein the controller operates the switches of the n phases at different duty ratios, when the controller determines that a specific condition is met; and wherein the controller measures the AC impedance of the fuel cell from the current waveform and voltage waveform of the fuel cell.

Abstract: To provide a voltage converter configured to suppress individual variation in voltage conversion ratio and configured to achieve a high voltage conversion ratio. A voltage converter comprising a reactor, a switching element, a diode, a current sensor, and a controller, wherein the controller detects a current value of the reactor several times in a switching period; wherein the controller calculates an estimated execution ON time length from a transition of a current value of the reactor detected in the switching period; wherein the controller calculates a difference between the estimated execution ON time length and a command ON time length instructed by the controller; and wherein, by using the difference, the controller corrects the command ON time length of the time when performing any of subsequent ON commands in a range not exceeding a predetermined command ON time upper limit value.

Abstract: To provide a power supply unit configured to determine the boundary between the operation modes (continuous mode and discontinuous mode) of a converter with high accuracy. The power supply unit is a power supply unit wherein the controller controls a value of output current of the power supply by controlling a duty ratio by switching the second switch; wherein the controller detects the current value of the reactor acquired by the current sensor, at a frequency of at least n (n is an integer of 2 or more) times in a cycle of the switching.

Abstract: A voltage control system includes: a converter controlling portion; a current value acquisition portion; and a voltage value acquisition portion. The converter controlling portion sets a duty ratio in a present cycle by adding an addition term to a feedforward term, the addition term being determined by use of a current deviation, which is a difference between a target value of an output current in the present cycle and a current measured value in a previous cycle, and the duty ratio in the previous cycle, the addition term being corresponding to an increase of the output current in the present cycle.

Abstract: A fuel cell vehicle according to the present disclosure includes: a fuel cell; a multiphase converter configured to control an output current of the fuel cell; a current sensor provided in each phase of the multiphase converter; an electric load configured to receive power supplied from the fuel cell; and a control unit. The control unit performs, when it detects an excess or a deficiency of electric energy of the electric load, replacement of phases driven by the multiphase converter while the output current of the fuel cell is kept constant, and determines, when the excess or the deficiency of the electric energy of the electric load is eliminated after the replacement of the phases, that an offset failure has occurred in the current sensor provided in the phase that has been driven before the replacement.

Abstract: A voltage control system includes a converter device, and a controller configured to set a duty ratio according to a current target value so as to cause the converter device to repeatedly perform a boost operation according to the duty ratio. The controller is configured to set the duty ratio by use of a basic term including a feedforward term, and an additional term, the feedforward term being derived by use of a measured value of a magnitude of an input of a reactor provided in the converter device and a measured value of a magnitude of an output of the reactor or by use of respective target values of the magnitude of the input and the magnitude of the output in the reactor, the additional term being derived by use of the variation of the current target value during one cycle.

Abstract: A fuel cell vehicle according to the present disclosure includes: a fuel cell; a multiphase converter configured to control an output current of the fuel cell; a current sensor provided in each phase of the multiphase converter; an electric load configured to receive power supplied from the fuel cell; and a control unit. The control unit performs, when it detects an excess or a deficiency of electric energy of the electric load, replacement of phases driven by the multiphase converter while the output current of the fuel cell is kept constant, and determines, when the excess or the deficiency of the electric energy of the electric load is eliminated after the replacement of the phases, that an offset failure has occurred in the current sensor provided in the phase that has been driven before the replacement.

Abstract: A fuel cell system includes a control section that: transmits a first current command value used to lower an output voltage of a fuel cell stack to a fuel cell converter when the output voltage becomes equal to or higher than a first voltage; transmits a second current command value used to boost the output voltage to the fuel cell converter when the output voltage becomes equal to or lower than a second voltage; stores the first current command value as a first storage value when the output voltage becomes equal to or lower than the second voltage; stores the second current command value as a second storage value when the output voltage becomes equal to or higher than the first voltage; and transmits a current command value that falls between the first storage value and the second storage value to the fuel cell converter.

Abstract: A fuel cell system includes: a fuel cell stack; a voltage sensor configured to detect voltage of the fuel cell stack; a fuel cell relay connected to the fuel cell stack; a switch connected between the fuel cell stack and the fuel cell relay; an overcurrent detector configured to detect an overcurrent flowing to the switch; and a power generation stop device configured to stop power generation of the fuel cell stack when the overcurrent detector detects the overcurrent and the detected voltage becomes a specified value or less.

Abstract: The present disclosure is made in order to reduce inaccuracy of current sensors. A fuel cell system includes a converter configured to convert output voltage of the fuel cell, and a current sensor including a preliminarily magnetized magnetic core and configured to measure current flowing in the converter from the fuel cell. A controller operates in a first driving mode in which a maximum current value in a target circuit of current measurement by the current sensor is lower than a current value for preliminary magnetization of the magnetic core, and a second driving mode in which the maximum current value in the target circuit is higher than the maximum current value in the target circuit in the first driving mode. When an accumulated temperature value of the current sensor in the first driving mode exceeds a threshold, the second driving mode is executed, followed by the first driving mode.

Abstract: The present disclosure is made in order to reduce inaccuracy of current sensors. A fuel cell system 100 comprises a converter 150 configured to convert output voltage of the fuel cell 1, and a current sensor CS1 including a preliminarily magnetized magnetic core MC1 and configured to measure current flowing in the converter 150 from the fuel cell 1. A controller 160 comprises, as driving modes of the fuel cell system 100, a first driving mode DM1 in which a maximum current value IL1max in a target circuit of current measurement by the current sensor CS1 is lower than a current value for preliminary magnetization of the magnetic core and a second driving mode DM2 in which the maximum current value IL2max in the target circuit is higher than the maximum current value IL1max in the target circuit in the first driving mode DM1.

Abstract: A fuel cell system includes a control section that: transmits a first current command value used to lower an output voltage of a fuel cell stack to a fuel cell converter when the output voltage becomes equal to or higher than a first voltage; transmits a second current command value used to boost the output voltage to the fuel cell converter when the output voltage becomes equal to or lower than a second voltage; stores the first current command value as a first storage value when the output voltage becomes equal to or lower than the second voltage; stores the second current command value as a second storage value when the output voltage becomes equal to or higher than the first voltage; and transmits a current command value that falls between the first storage value and the second storage value to the fuel cell converter.

Abstract: A fuel cell system includes: a fuel cell stack; a voltage sensor configured to detect voltage of the fuel cell stack; a fuel cell relay connected to the fuel cell stack; a switch connected between the fuel cell stack and the fuel cell relay; an overcurrent detector configured to detect an overcurrent flowing to the switch; and a power generation stop device configured to stop power generation of the fuel cell stack when the overcurrent detector detects the overcurrent and the detected voltage becomes a specified value or less.