Abstract: A device and method for improving stack performance of a fuel cell system are provided. The device includes a fuel cell controller that operates a stack of a normal-pressure fuel cell system. When the fuel cell controller determines that an operating state of the stack is normal and a current intake air pressure is decreased as a result of monitoring the current intake air pressure, a current output, and an exterior air temperature of the stack, the fuel cell controller increases the amount of air to be supplied into the stack by adjusting a range of a theoretical air ratio which is a theoretical ratio of an air amount to a coolant temperature in the stack.

Abstract: A system and method of controlling a start of a fuel cell are provdied. The method includes comparing a derived internal temperature of a stack and a predetermined reference temperature value and determining whether the internal temperature of the stack is less than the reference temperature value when an ON signal of the start of the fuel cell is received. A required heat value is then derived using the internal temperature of the stack when the derived internal temperature of the stack is less than the reference temperature value. A temperature of the stack of the fuel cell is increased until a cumulative heat value caused by a temperature increase of the stack of the fuel cell is equal to the required heat value.

Abstract: Provided is a piezoelectric stack transducer. In a transducer portion, a plurality of piezoelectric transducers which output maximum amplitude at different frequencies are continuously stacked. A stacked electrode portion is provided on both surfaces of each of the plurality of continuously stacked piezoelectric transducers and supplies an electric signal so that vibration is generated. In this case, the plurality of piezoelectric transducers have different diameters. According to the present invention, it is possible to implement a piezoelectric stack transducer which exhibits constant amplitude (output) at different frequencies by piezoelectric transducers exhibiting different amplitudes at respective frequencies according to natural frequencies supplementing amplitude of a different piezoelectric transducer.

Abstract: There is provided a flow meter using at least one ultrasonic transducer. The flow meter includes an ultrasonic transducer, a wedge that has a sloped surface formed on a top portion of the wedge and oblique with respect to a downward direction, and a dented portion formed in a half-cylinder shape along a longitudinal direction of the sloped surface; and a rotation portion that has a plane section where the ultrasonic transducer is positioned, and a curved section extended from two opposite edges of the plane section and curved in a semicircular shape to be contacted with the dented portion.

Abstract: The present invention provides a relative humidity and condensed water estimator for a fuel cell and a method for controlling condensed water drain using the same. Here, the relative humidity and condensed water estimator is utilized in control of the fuel cell system involving control of anode condensed water drain by outputting at least two of signals comprising air-side relative humidity, hydrogen-side relative humidity, air-side instantaneous or cumulative condensed water, hydrogen-side instantaneous or cumulative condensed water, instantaneous and cumulative condensed water of the humidifier, membrane water contents, catalyst layer oxygen partial pressure, catalyst layer hydrogen partial pressure, stack or cell voltage, air-side catalyst layer relative humidity, hydrogen-side catalyst layer relative humidity, oxygen supercharging ratio, hydrogen supercharging ratio, residual water in a stack, and residual water in a humidifier.

Abstract: A method for controlling a cold start of a fuel cell vehicle includes detecting and storing temperatures at an inlet and an exit of fuel cell cooling water a plurality of times after turning-off of the fuel cell vehicle. A start sequence is controlled based on the lowest temperature of the stored temperatures and temperatures at the inlet and exit of the cooling water at a restart of the vehicle. Accordingly, it is possible to enhance start-up stability and driving stability by controlling a cold start sequence according to an internal state of the fuel cell stack.

Abstract: Disclosed herein is a method for estimating a power of a fuel cell. The method includes estimating a predictive current at a predetermined voltage in a controller, based on a present current-voltage characteristic of the fuel cell while the temperature of the fuel cell is being raised, estimating a first power, based on the estimated predictive current and the predetermined voltage, after the step of estimating the predictive current, estimating a second power based on a cell voltage rate while estimating the first power, and calculating an available power of the fuel cell, based on the first power and the second power, after the step of estimating the first power and the step of estimating the second power are performed.

Abstract: A coolant bypass structure includes a main loop forming a channel in which coolant circulates; a bypass loop connected to the main loop and forming a selective bypass channel; and a stack bypass valve provided between the main loop and the bypass loop to open and close the bypass loop according to a predetermined temperature, and provided with an outlet temperature sensor. The coolant bypass structure may improve marketability by decreasing the starting time of the fuel cell vehicle in a frozen state and improve power efficiency.

Abstract: A warning alarm apparatus for a steering wheel includes at least one piezoelectric transducer provided in the rim of the steering wheel; a current supplier; one or more sensors, equipped in the steering wheel or a motor vehicle, sense a dangerous factor; and a controller that determines whether a sensor value sensed by the sensor is included in a warning alarm range, and controls operation of the current supplier according to the sensor value.

Abstract: The present invention provides a relative humidity and condensed water estimator for a fuel cell and a method for controlling condensed water drain using the same. Here, the relative humidity and condensed water estimator is utilized in control of the fuel cell system involving control of anode condensed water drain by outputting at least two of signals comprising air-side relative humidity, hydrogen-side relative humidity, air-side instantaneous or cumulative condensed water, hydrogen-side instantaneous or cumulative condensed water, instantaneous and cumulative condensed water of the humidifier, membrane water contents, catalyst layer oxygen partial pressure, catalyst layer hydrogen partial pressure, stack or cell voltage, air-side catalyst layer relative humidity, hydrogen-side catalyst layer relative humidity, oxygen supercharging ratio, hydrogen supercharging ratio, residual water in a stack, and residual water in a humidifier.

Abstract: A control method and system for starting a fuel cell vehicle is provided. The method includes setting a first output power that is an output power required for driving the vehicle and beginning to increase the fuel cell temperature after setting the first output power. In addition, available output power of a fuel cell is estimated and a discharge power of a high-voltage battery is received. A second output power that is a sum of the available output power of the fuel cell and the discharge power of the high-voltage battery is calculated. The method further includes determining whether the second output power is greater than the first output power and determining whether starting of the vehicle is allowable based on the determination of whether the second output power is greater than the first output power.

Abstract: A printer nozzle apparatus, including a nozzle that sprays ink, at least one vibration unit that is arranged on one surface of the nozzle and of a ring shape, and a controller that controls a vibration frequency of the vibration unit.

Abstract: There is provided a flow meter using at least one ultrasonic transducer. The flow meter includes an ultrasonic transducer, a wedge that has a sloped surface formed on a top portion of the wedge and oblique with respect to a downward direction, and a dented portion formed in a half-cylinder shape along a longitudinal direction of the sloped surface; and a rotation portion that has a plane section where the ultrasonic transducer is positioned, and a curved section extended from two opposite edges of the plane section and curved in a semicircular shape to be contacted with the dented portion.

Abstract: An apparatus and method for controlling cooling of electronic components of a fuel cell vehicle are provided. The apparatus for controlling cooling of electronic components connected in series and parallel with a coolant loop in a fuel cell vehicle using a pump includes a monitor configured to collect measured temperature of the electronic components and a measured temperature of a coolant through a plurality of temperature sensors, and a controller configured to control the RPM of the pump based on the measured temperatures and at least one of electronic component temperature maps, a coolant temperature map and a temperature difference map representing temperature differences between the electronic components and coolant, the controller controlling the RPM of the pump using over-temperature set information and over-temperature reset information of each temperature map.

Abstract: A printer nozzle apparatus, including a nozzle that sprays ink, at least one vibration unit that is arranged on one surface of the nozzle and of a ring shape, and a controller that controls a vibration frequency of the vibration unit.

Abstract: A method for controlling a cold start of a fuel cell vehicle includes detecting and storing temperatures at an inlet and an exit of fuel cell cooling water a plurality of times after turning-off of the fuel cell vehicle. A start sequence is controlled based on the lowest temperature of the stored temperatures and temperatures at the inlet and exit of the cooling water at a restart of the vehicle. Accordingly, it is possible to enhance start-up stability and driving stability by controlling a cold start sequence according to an internal state of the fuel cell stack.

Abstract: A piezoelectric power generator using wind power is provided. To elaborate, the piezoelectric power generator has a central axis unit with a charger, a piezoelectric film supporting frame engaged onto an outer circumference surface of the central axis unit, and a piezoelectric film having a pre-set area and at least one side engaged to at least one of one side part of the piezoelectric supporting frame and the central axis unit. In addition, the piezoelectric film supporting frame has a shape corresponding to a shape of an edge of the piezoelectric film to surround the edge of the piezoelectric film.

Abstract: A warning alarm apparatus for a steering wheel includes at least one piezoelectric transducer provided in the rim of the steering wheel; a current supplier; one or more sensors, equipped in the steering wheel or a motor vehicle, sense a dangerous factor; and a controller that determines whether a sensor value sensed by the sensor is included in a warning alarm range, and controls operation of the current supplier according to the sensor value.

Abstract: A system and method for emergency starting of a fuel cell vehicle is provided. In particular, a high-voltage converter, a balance of power (BOP), and a controller are included in the system. The high-voltage converter is configured such that one side thereof is connected to a high-voltage battery via a battery switch and the other side thereof is connected in parallel to a plurality of fuel cells. The BOP is connected in parallel to the high-voltage converter and the fuel cells. The controller is configured to control the power supplied from the high-voltage battery to the BOP without conversion by connecting the battery switch upon the failure of the high-voltage converter or high-voltage battery.

Abstract: An apparatus and method for controlling cooling of electronic components of a fuel cell vehicle are provided. The apparatus for controlling cooling of electronic components connected in series and parallel with a coolant loop in a fuel cell vehicle using a pump includes a monitor configured to collect measured temperature of the electronic components and a measured temperature of a coolant through a plurality of temperature sensors, and a controller configured to control the RPM of the pump based on the measured temperatures and at least one of electronic component temperature maps, a coolant temperature map and a temperature difference map representing temperature differences between the electronic components and coolant, the controller controlling the RPM of the pump using over-temperature set information and over-temperature reset information of each temperature map.