Abstract:
A housing that retains a fuel cell stack includes a casing that defines a cavity. A first plate is retained within the cavity at a first-end of the casing. A second plate is partially received into the cavity at a second end of the casing and is secured to the casing. The fuel cell stack is disposed between the first and second plates. The first and second plates exert a compressive force on the fuel cell stack.
Abstract:
An integrated cell voltage unit for monitoring the voltage of each fuel cell in a fuel cell stack that is easily and reliably electrically coupled to the bipolar plates of the fuel cell stack. The bipolar plates of the fuel cell stack are equipped with a specialized tab connector that engages with a corresponding electrical connector on the cell voltage unit. Either the tab connectors on the bipolar plates or the corresponding connectors on the cell voltage unit include flexible members to provide a suitable electrical friction engagement. The cell voltage unit is attached to the bipolar plates and does not require its own separate housing. In one embodiment, the housing of the fuel cell stack includes a recessed portion in which the cell voltage unit is positioned.
Abstract:
Electrical resistance heating elements recessed in the terminal plates, or the cell end plates, of a fuel cell stack at the interfaces therebetween are energized by electricity generated by the stack to heat the end cells during start-up of a frozen stack. The flow of current in the heating elements is ended when the temperature of the end cell(s) reach(es) a prescribed above-freezing temperature.
Abstract:
A compressor arrangement for the operation of a fuel cell system, wherein a compressed air flow can be delivered from the compressor arrangement, which is driven by an electric motor, to the fuel cell system and wherein the compressor arrangement and optionally the electric motor are at least partly surrounded by a sound insulation, is characterized in that the sound insulation is permeable to air and is provided within a housing which at least partly surrounds the compressor and preferably also the electric motor, and in that at least a part of the air intake flow for the compressor arrangement can be directed through the air permeable sound insulation before it enters into the compressor inlet.
Abstract:
A DC/DC converter for a fuel cell includes an input node for receiving DC supply power from the fuel cell. An output node provides a DC output voltage. An inductor has inductance which varies with respect to inductor current. The inductor includes a first terminal and a second terminal. The first terminal is coupled with the input node for receiving DC supply power from the fuel cell. A switch is coupled between the second terminal of the inductor and ground. A control circuit switches the switch between an open position and a closed position.
Abstract:
Various embodiments provide two-phase boost converters. One two-phase boost converter includes a node configured to be coupled to an input voltage and a transformer coupled to the node. The transformer includes primary and secondary windings, an inductor coupled in series with the primary winding, and an inductor coupled in series with the secondary winding. Another two-phase boost converter includes an inductor configured to be coupled to an input voltage, a node coupled to the inductor, and a transformer coupled to the node. The transformer includes primary and secondary windings, an inductor coupled in series with the primary winding, and an inductor coupled in series with the secondary winding. Yet another two-phase boost converter includes a transformer coupled to first and second external inductors. The transformer includes primary and secondary windings, an inductor coupled in series with the primary winding, and an inductor coupled in series with the secondary winding.
Abstract:
A system and method for controlling the voltage on a high voltage bus in a fuel cell system in response to a failed high voltage battery. The method includes determining if the high voltage battery has failed, and disconnecting the battery from the high voltage bus in response to a failure. The method measures the voltage of the fuel cell stack by a DC boost circuit and converts the measured voltage to a voltage set-point value that sets the voltage on the high voltage bus, where the voltage set-point value changes as the measured voltage changes. A supervisory controller sets the media flow to the fuel cell stack and determines a minimum stack voltage limit value based on the stack maximum current draw that is used to determine a high voltage bus lower limit value.
Abstract:
A system for reducing oscillations on a high voltage bus. The system includes a high voltage battery electrically coupled to the high voltage bus and a DC/DC boost converter electrically coupled to the high voltage bus and a fuel cell stack. The DC/DC converter includes a current controller that selectively controls the current provided by the fuel cell stack. A system controller provides a stack current set-point to the DC/DC converter. The DC/DC converter includes a voltage device that receives a voltage signal from the bus and provides a time derivative of the voltage signal that defines voltage changes on the bus over time. The time derivative signal is provided to a summer that adjusts the current stack set-point to provide a modified current set-point to the current controller that selectively adjusts the current provided by the fuel cell stack to dampen oscillations on the high voltage bus.
Abstract translation:一种降低高压母线振荡的系统。 该系统包括电耦合到高压总线的高电压电池和电耦合到高压总线的DC / DC升压转换器和燃料电池堆。 DC / DC转换器包括电流控制器,其选择性地控制由燃料电池堆提供的电流。 系统控制器向DC / DC转换器提供堆栈电流设定点。 DC / DC转换器包括从总线接收电压信号的电压装置,并且提供定义总线上的电压变化随时间变化的电压信号的时间导数。 时间导数信号被提供给调整当前堆叠设定点的加法器,以向电流控制器提供修改的电流设定点,该电流控制器选择性地调节由燃料电池堆提供的电流以抑制高压母线上的振荡。
Abstract:
A fuel cell assembly having a terminal plate that is isolated from fluid flows passing to the fuel cell stack through manifolds is provided. A corrosion resistant member is positioned between the fuel cell stack and the terminal plate and sealingly engages with the manifold. The sealing engagement between the manifold and the corrosion resistant member prevents fluid flowing through the manifold to the fuel cell stack from contacting the terminal plate. Thus, a fuel cell assembly according to the present invention can be operated while preventing a fluid flow through the manifold from contacting the terminal plate.
Abstract:
Systems and methods are provided for regulating the state of charge of a battery. An exemplary electrical system includes a fuel cell coupled to a bus and a battery coupled to the bus via a switching arrangement coupled to a capacitor. An exemplary method for operating the electrical system involves operating the switching arrangement such that a voltage of the battery is substantially equal to a voltage of the fuel cell when a state of charge of the battery is greater than a lower threshold value and less than an upper threshold value, and operating the switching arrangement to couple the capacitor electrically in series between the battery and the bus when the state of charge of the battery is not between the lower threshold value and the upper threshold value.