Plug Power Inc.

Electric Power Research Institute Incorporated

Robert A Lacy

Russel Hugh Marvin

David E James

Richard J Murphy

Jonathan B Wright

Delano D Wilson

Dale A Douglass

James J Burke

An apparatus includes a fuel cell subsystem, a first circuit and a second circuit. The fuel cell subsystem produces power for a load in response to receiving a flow of a reactant, and the first circuit is coupled to the fuel cell subsystem to halt the flow to the fuel cell stack and isolate the fuel cell stack from the load after the flow is halted. The second circuit monitors a characteristic of the fuel cell subsystem and receives power from the stack to dissipate a portion of the reactant that remains in the stack while the flow is halted.

Residual fuel dissipation for a fuel cell stack

A system includes a fuel cell subsystem, switches and a controller. The fuel cell subsystem is adapted to provide power that is capable of being consumed by residential loads, and the fuel cell subsystem is sized to provide power up to a first power threshold that is less than a maximum power threshold that is capable of being consumed by the residential loads. The controller is adapted to determine the power that is consumed by the residential loads and based on the determined power, operate the switches to selectively regulate electrical connections between the residential loads and the fuel cell subsystem to keep the power approximately below the first power threshold.

Residential load shedding

A method includes establishing a fuel flow through a fuel cell stack to produce a current. The voltages of the fuel cell stack are scanned to determine the minimum cell voltage. A maximum limit on the current is set based at least in part on the minimum cell voltage.

Regulating the maximum output current of a fuel cell stack

A fuel cell system includes a fuel cell stack, an inverter, a reformer and a circuit. The fuel cell stack is adapted to produce heat in response to a fuel flow, and the inverter is coupled to the fuel cell stack and is adapted to use electrical energy produced by the fuel cell stack to furnish electrical power that is received by a power grid. The reformer is adapted to produce the fuel flow, and the circuit is adapted to interact with the reformer to produce an approximate predetermined amount of heat. The circuit also determines cell voltages of the fuel cell stack, selects the minimum cell voltage, and interacts with the inverter to regulate the amount of the electrical power that is furnished by the inverter based on the selected voltage.

Regulating a fuel cell powered heating system

A system includes a divider network, a memory and a circuit. The divider network is adapted to be coupled to fuel cells of a fuel cell stack and provide pairs of signals. Each pair of signals is associated with a different fuel cell and indicates a terminal voltage of the associated cell and another voltage common to the pair of signals. The memory stores indications of different common mode gains, and each common mode gain indication is associated with a different one of the pairs of signals. The circuit is coupled to the memory and adapted to generate an indication of the terminal voltage from each pair based on the associated common mode gain indication.

Measuring cell voltages of a fuel cell stack

A selected point in an electric power system is monitored for subsequent fault analysis. The voltage and current at the point is continuously sampled with samples for a predetermined period of time being temporarily stored in memory. In response to a Fault Event, voltage and current samples at differing sample rates and for differing periods of time are recorded. Voltage and current samples after a Cold Load Pickup are recorded, also the recorded samples allow later analysis of the fault and identification of the cause of the fault.

Growing community of inventors

Scotia, NY, United States of America

Robert A Lacy