Abstract:
A fuel cell stack assembly comprising an electrical connection system for cell voltage monitoring is described. The fuel cell stack (80) has a plurality of fuel cells disposed in a stacked configuration, each cell having a membrane-electrode assembly (MEA) sandwiched between an anode flow field plate and a cathode flow field plate. The flow field plates (21) each extend to a lateral face of the fuel cell stack and each has an exposed portion generally coplanar with the lateral face of the fuel cell stack surface. A connector assembly has an array of contacts (83) each configured to bias against, and form electrical contact with, a respective one of selected flow field plates (21) at a contact zone thereof and each contact is biased against its respective flow plate (21) in a direction in the plane of the respective flow field plate. The exposed portion may be an exposed edge of the respective flow field plate and each contact is biased against the exposed edge of its respective flow plate. Alternatively, the exposed portion may be a buckled or folded peripheral portion of the respective flow field plate and each contact is biased against the buckled or folded portion of its respective flow plate.
Abstract:
A switching controller for coupling one of a plurality of voltage sources to a load. The switching controller is configured to receive a characteristic of one of the plurality of voltage sources; for each of the plurality of voltage sources, set a proportion of a switching period of a control signal during which the voltage source is connected to the load, wherein the proportion of the switching period is set based on the received characteristic of one of the plurality of voltage sources; and control which of the plurality of voltage sources is connected to the load in accordance with the control signal.
Abstract:
A fuel cell stack assembly comprises a stack of fuel cells, each fuel cell having an air flow conduit with an input/output ventilation aperture disposed on a ventilation face of the stack, the ventilation apertures forming an array over said ventilation face of the stack. A membrane is moveable between a first configuration in which the ventilation face is occluded and a second configuration in which the ventilation face is not occluded. The membrane is rollable between the first configuration and the second configuration. Ventilation of the fuel cell stack is thereby controlled by the position of the membrane, e.g. during fuel cell start up and/or shut down procedures or for hydration control of the fuel cells.
Abstract:
A method of operating a fuel cell assembly comprising a plurality of fuel cells connected together for collectively providing power to a load, each fuel cell including an anode and a cathode, the method comprising selectively providing an electrical connection between the anode and the cathode of at least one of the fuel cells of the assembly for lowering the voltage across the fuel cell independent of the load.
Abstract:
A switching controller for coupling one of a plurality of voltage sources to a load. The switching controller is configured to receive a characteristic of one of the plurality of voltage sources; for each of the plurality of voltage sources, set a proportion of a switching period of a control signal during which the voltage source is connected to the load, wherein the proportion of the switching period is set based on the received characteristic of one of the plurality of voltage sources; and control which of the plurality of voltage sources is connected to the load in accordance with the control signal.
Abstract:
A fuel cell stack assembly comprises a stack of fuel cells, each fuel cell having an air flow conduit with an input/output ventilation aperture disposed on a ventilation face of the stack, the ventilation apertures forming an array over said ventilation face of the stack. A membrane is moveable between a first configuration in which the ventilation face is occluded and a second configuration in which the ventilation face is not occluded. The membrane is rollable between the first configuration and the second configuration. Ventilation of the fuel cell stack is thereby controlled by the position of the membrane, e.g. during fuel cell start up and/or shut down procedures or for hydration control of the fuel cells.