An electrical power generating system for providing auxiliary or backup power to a load bus. The system may be used indoors, and generally includes a fuel cell unit comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the fuel cell, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter comprising a first AC output. The system includes a contactor connected between the first AC output and an AC load bus. The AC load bus comprises an AC voltage, and a controller comprising inputs is adapted to sense a phase, a frequency, and a magnitude of the first AC output and the AC voltage and close the contactor when they substantially match.

A cathode oxygen depletion (COD) control method is provided. The method includes determining whether a COD heater operates and calculating power generation and power consumption when the COD heater operates. Additionally, the power consumption is adjusted by comparing the calculated power generation and power consumption.

An operation control system and method of a fuel cell vehicle are provided. The system includes a fuel cell, an air supply device operated by a motor, to supply air to the fuel cell and a sensing unit that senses an abnormal operation of the air supply device. A calculation unit calculates a lower-limit voltage of the air supply device required for normal operation of the air supply device when the sensing unit senses abnormal operation of the air supply device. A controller then adjusts a voltage supplied to the air supply device based on the calculated lower-limit voltage.

A power generating system comprised of a hydrogen fuel cell and rechargeable battery connected together in series to be used as a load following system without the use of a DC-DC converter. The hydrogen fuel cell's cathode air compressor is driven off of the output of this power generation system. This is made possible by the following innovations: A novel way to wire the systems in series with the use of switches and bypass diodes, a method to limit the system output voltage so that we do not exceed the maximum voltage of downstream components, and an isolated DC-DC converter to charge the rechargeable battery with the hydrogen fuel cell.

A hydrogen generation system for generating hydrogen and electrical power includes a power supply, a reformer-electrolyzer-purifier (REP) assembly including at least one fuel cell including an anode and a cathode separated by an electrolyte matrix, at least one low temperature fuel cell, and a hydrogen storage. The at least one fuel cell is configured to receive a reverse voltage supplied by the power supply and generate hydrogen-containing gas in the anode of the at least one fuel cell. The at least one low temperature fuel cell is configured to receive the hydrogen-containing gas output from the REP assembly. The at least one low temperature fuel cell is configured to selectably operate in a power generation mode in which the hydrogen-containing gas is used to generate electrical power and a power storage mode in which the hydrogen-containing gas is pressurized and stored in the hydrogen storage.

Provided is a vehicle power source system including: a main battery configured to supply power to a drive motor of a vehicle; a fuel cell configured to supply power at least to the main battery; a main line connecting the main battery and the fuel cell; a first voltage translator placed on the main line and including a charging portion and a voltage transforming portion, the first voltage translator being configured to adjust an output voltage of the fuel cell; a relay provided between the charging portion and the fuel cell in the main line; and a sub-battery connected to an auxiliary machine power supply line via which power is supplied to an auxiliary machine of the vehicle or the fuel cell. The vehicle power source system includes a second voltage translator connected between the relay and the charging portion in the main line and configured to adjust power to be supplied from the sub-battery to the charging portion.

A motor drive control method is provided for controlling a speed of a motor such that a measured speed value of the motor follows a speed command value. The motor drive control method includes an on/off driving operation of driving a torque of the motor based on the speed command value in such a way that the torque of the motor is repeatedly turned on/off on preset cycle and duty. The motor drive control method and system can markedly enhance efficiency of a motor by reducing switching loss and current ripple loss of an inverter in a low-speed driving period of a high-speed motor.

A vehicle system includes a motor, a first device connected to the motor and configured to supply the motor with power, a fuel cell connected to the first device and configured to charge the first device, a second device connected to the fuel cell, a first converter interposed between the fuel cell and the first device and configured to adjust a voltage from one of the fuel cell or the first device and to supply power to the other, a second converter interposed between the fuel cell and the second device and configured to adjust a voltage from the second device and to apply the adjusted voltage to the fuel cell, and a third converter interposed between the first device and the second device and configured to adjust a voltage from one of the first device or the second device and to supply power to the other.

Provided is a vehicle power source system including: a main battery configured to supply power to a drive motor of a vehicle; a fuel cell configured to supply power at least to the main battery; a main line connecting the main battery and the fuel cell; a first voltage translator placed on the main line and including a charging portion and a voltage transforming portion, the first voltage translator being configured to adjust an output voltage of the fuel cell; a relay provided between the charging portion and the fuel cell in the main line; and a sub-battery connected to an auxiliary machine power supply line via which power is supplied to an auxiliary machine of the vehicle or the fuel cell. The vehicle power source system includes a second voltage translator connected between the relay and the charging portion in the main line and configured to adjust power to be supplied from the sub-battery to the charging portion.

An electrical system includes a stack (3) of electrochemical cells (5), a power converter (9) electrically connected to the stack (3), a voltage comparator (7) for comparing the voltage at the terminals of at least one group of at least one electrochemical cell (5) of the stack (3) to a threshold voltage, and a control module (11) for controlling the converter (9). The control module (11) includes a generator (74) for generating a control instruction for controlling the converter (9) and a transmission member (76) for transmitting the control instruction to the converter (9). The voltage comparator (7) is suitable for transmitting a signal to the transmission member (76). The signal consists of a first instruction from an instruction for transmitting and an instruction for blocking the control instruction when the compared voltage is higher than the threshold voltage, and a second instruction from the instructions for transmitting and blocking the control instruction when the compared voltage is lower than or equal to the threshold voltage.