Abstract:
A method and an apparatus using a power transistor in a fuel cell stack diagnostic system provides an apparatus using a power transistor in a fuel cell stack diagnostic system. The apparatus includes a regenerative braking detector that detects regenerative braking of a fuel cell vehicle equipped with a fuel cell stack diagnostic system; a voltage rise determiner that determines whether a voltage rise due to regenerative braking of a fuel cell vehicle is a predetermined value or more; and a power transistor controller that controls an AC signal generator so that the voltage due to the regenerative braking is discharged by the power transistor, when the voltage rise due to regenerative braking determined by the voltage rise determiner is a predetermined value or more.
Abstract:
A fuel cell system includes an air supply unit for supplying air containing oxygen to a fuel cell stack. A humidifier humidifies the supplied air. An air supply line is connected between a cathode inlet of the fuel cell stack and the humidifier to supply the humidified air to the fuel cell stack. A cathode-side exhaust line is connected between a cathode outlet of the fuel cell stack and the humidifier to supply a cathode exhaust gas discharged from a cathode of the fuel cell stack to the humidifier for humidification in the humidifier. A unified valve module includes a bypass line connected between the air supply line and the cathode-side exhaust line and an outward discharge port discharging the cathode exhaust gas to outside, and controls a gas flow between the humidifier and the fuel cell stack and between the bypass line and the outward discharge port.
Abstract:
A method for manufacturing a manifold for a fuel cell with a multilayer structure by injection-molding individual manifolds, each having welding projections and welding guides, and bonding the injection-molded individual manifolds by vibration welding includes arranging welding projections of an upper individual manifold and welding guides of a lower individual manifold to be engaged with each other while maintaining a uniform gap between each other to bond a plurality of individual manifolds in an up and down stacking structure, pressing the lower individual manifold upward, and applying vibration to the upper individual manifold in the left and right direction, thus bonding the upper and lower individual manifolds. Among the welding projections of the upper individual manifold, a non-horizontal welding projection whose longitudinal direction does not coincide with the vibration direction of the individual manifold has a variable height.