Toyota Motor Engineering & Manufacturing North America, Inc.

Toyota Jidosha Kabushiki Kaisha

Daniel Charles Folick

Jared Michael Farnsworth

Shigeki Hasegawa

Luke Alan Rippelmeyer

Andrew G Sata

Naoki Tomi

Dakota Kelley

Matthew K McClory

Christopher M Bulpitt

Kentaro Fukuda

Christopher Lee Rovik

Scott A Friedman

Nobukazu Mizuno

Takehito Yokoo

Laura E Bower

Arlo C Eitzer

Daniel K Lim

Jonathan J Sander

Motoyuki Kimata

Yohei Okamoto

Tomoo Yoshizumi

Ron J Toth

Rathin Karhu

A vehicle includes a fuel cell power management system including: a fuel cell; a battery; a charge sensor operatively coupled to the battery; a speedometer; and a processor that includes a memory. The processor is configured to calculate a mapping of desired fuel cell power output as a function of the battery charge and the speed of the vehicle and, using the mapping, the battery charge, the speed of the vehicle, and a motor power request, calculate the desired traction power output of the fuel cell. The processor then sets the traction power output of the fuel cell to the desired traction power output of the fuel cell, sets the desired traction power output of the battery to the motor power request minus the traction power output of the fuel cell, and sets the traction power output of the battery to the desired traction power output of the battery.

Fuel cell power management system

Systems and methods are provided for monitoring and controlling pump speeds to maintain a balanced pressure drop between each of the multiple fuel cell systems or circuits. In systems where a single radiator is used to maintain desired temperatures of multiple fuel cells, back flow can nevertheless be avoided. Control maps may be used to meet minimum pump speeds as a function of a flow splitting valve position and target flow rate (to prevent or avoid fluid back flow through a fuel cell stack). Control maps may also be used to determine a minimum pump speed as a function of three-way valve position (to prevent fluid back flow across a radiator path).

Multiple fuel cell radiator system

System, methods, and other embodiments described herein relate to safely ceasing fuel cell (FC) operation and idling components of a generator. In one embodiment, a method includes ceasing power generation by reducing fuel to an FC within a generator while maintaining energy to sensitive components by a battery. The method also includes idling a direct current (DC) converter and a load inverter associated with the power generation before idling the battery. The method also includes, upon successfully completing tests and powering down non-critical components of the generator, entering the generator into a standby status.

Systems and methods for powering down a generator including a fuel cell

A fuel cell system includes a plurality of fuel cell units each configured to generate lower-voltage DC power. The fuel cell system includes a plurality of DC-DC converters each electrically connected to each of the fuel cell units and configured to convert the lower-voltage DC power to higher-voltage DC power. The fuel cell system includes a primary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a primary load. The fuel cell system includes an auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load.

Fuel cell system

Systems and methods for monitoring the isolation resistance of one or more fuel cells are described herein. In one example, a system includes a current transformer having a hollow core. First and second portions of a load line from a fuel cell are located within the hollow core. The first portion of the load line is electrically between an anode of a fuel cell and an electrical load, while the second portion of the load line being electrically between a cathode of the fuel cell and the electrical load. The current transformer is configured to output an electrical signal proportional to a current passing through the hollow core. This electrical signal can then be used to determine the isolation resistance of the fuel cell.

System and method for indirectly monitoring an isolation resistance of one or more fuel cells

Systems and methods are provided for modularizing a system. Parallel power systems having electronically isolated high voltage systems facilitate modulization. A control system is provided that optimizes the distribution of a power demand and/or a torque request so as to keep the efficiency, durability, drivability and/or safety of the system within an optimum range. In some cases, the distribution of power is uneven, so as to extend the battery life, while in other cases, the power draw on battery systems are kept equal and constant so as to properly manage the state of charge of the parallel power systems. In still other cases, the chosen power distribution keeps the power demand and/or torque request between minimum and maximum levels/capacity, and the power distribution avoids on/off of an individual power system.

Modular fuel cell system architecture and a control system for distributing power to the modules

A system for controlling DC-to-DC converters connected in parallel can include a first DC-to-DC converter, a second DC-to-DC converter, and a controller. The first DC-to-DC converter can be connected between a first node and a second node. The first DC-to-DC converter can be configured to maintain a voltage level at the second node. The second DC-to-DC converter can be connected between the first node and the second node. The controller can be configured to measure a current through the first DC-to-DC converter. The controller can be configured to cause, in response to a measure of the current being in a specific relationship with respect to a threshold current, a change in electric power being conveyed through the second DC-to-DC converter to cause the second DC-to-DC converter to respond to a subsequent change in electric power being conveyed through the second node.

Controlling DC-to-DC converters connected in parallel

A system for reducing overdraw of power in a vehicle includes a power source having a battery and a fuel cell circuit. The system further includes an ECU that transmits a power limit signal to a vehicle controller, the power limit signal corresponding to an instantaneous maximum amount of power of the power source. The ECU also determines a battery allowed power corresponding to an amount of power available to be drawn from the battery to cause the SOC of the battery to remain above a lower SOC threshold. The ECU also determines a current battery power draw from the battery corresponding to an instantaneous amount of power being drawn from the battery. The ECU is designed to reduce the instantaneous maximum amount of power in the power limit signal when the current battery power draw is greater than the battery allowed power, reducing the current battery power draw.

System and method for feedback-based reduction of system overdraw in a fuel cell system

A system for reducing overconsumption of power in a vehicle includes a power source including a battery having a state of charge (SOC), and a fuel cell stack that generates electricity. The system further includes an electronic control unit (ECU) coupled to the power source and designed to receive a power request corresponding to a requested amount of power from the power source. The ECU is further designed to determine a fuel cell power amount corresponding to an amount of the electricity generated by the fuel cell stack to achieve the requested amount of power. The ECU is further designed to determine an overconsumption event when a current power consumption corresponding to a total amount of power being drawn from the power source is greater than the power request. The ECU is further designed to increase the fuel cell power amount in response to determining the overconsumption event.

System and method for reducing battery overconsumption in a fuel cell system

Described are systems and methods for directly monitoring the conductivity of the coolant used to regulate the temperature of a fuel cell. The system includes a coolant loop that acts as a conduit for the coolant, an ion exchanger configured to deionize the coolant, and a conductivity sensor configured to output an electrical signal indicating a conductivity of the coolant. The system also includes a processor in communication with the conductivity sensor and a memory having instructions that, when executed by the processor, cause the processor to determine the conductivity of the coolant based on the electrical signal from the conductivity sensor and determine when the ion exchanger requires servicing based on the conductivity of the coolant.

System and method for directly monitoring the conductivity of coolant used to regulate the temperature a fuel cell

A container for a fuel cell system includes a system frame configured to house one or more components of a fuel cell system. The container also includes a plurality of fuel cells supported by the system frame and configured to provide power to an external unit. The container also includes a raised floor configured to support the plurality of fuel cells. The container also includes a cooling system. The cooling system includes a central cooling pipe located underneath the raised floor, a plurality of fuel cell cooling pipes connected to the central cooling pipe and to each fuel cell, and a cooling pipe valve configured to regulate the pressure of the cooling system.

Container for a fuel cell system

The systems, devices, and methods described herein relate to heating and cooling automotive fuel cells. A proportional-integral-derivative (PID) controller may be used to control the temperature of fluid in the fuel cells. The PID may be configured to calculate and control the saturation limits of the I-term of the PID controller to reduce integral wind-up.

PI control partial derivative based I-term for wind-up prevention

A system for controlling gas flow in a fuel cell circuit includes a fuel cell stack, a pressure sensor, and a valve to adjust a flow of gas through the fuel cell circuit. The system further includes an ECU designed to estimate pressure values of the gas at multiple locations in the fuel cell circuit based on the detected pressure of the gas and based on flow resistance values (including at the valve), the estimated pressure values including an estimated sensor pressure value at a location of the pressure sensor. The ECU is further designed to determine a pressure deviation between the detected pressure and the estimated sensor pressure value. The ECU is further designed to adjust the flow resistance value of the valve to determine a final flow resistance value of the valve that causes the pressure deviation to reach or drop below a threshold deviation amount.

Air system pressure observer control method for fuel cell system

Systems and methods for controlling fluid flow in a fuel cell circuit of a vehicle. A system may have a fuel cell stack configured to receive hydrogen gas. The system may have a current sensor configured to detect current flowing through the fuel cell stack. The system may have a plurality of actuators, which may include at least one injector, a pump, and a shut valve. The system may have an electronic control unit (ECU). The ECU may estimate pressures of the hydrogen gas and non-hydrogen gases in the circuit. The ECU may determine a current increase rate based on the detected current. The ECU may apply a compensatory hydrogen gas stoic to a base hydrogen gas stoic to meet a target hydrogen gas stoic by controlling one or more of the actuators based on the estimated pressures when the current increase rate is above a predetermined threshold value.

Control systems and methods to meet fuel cell fuel demand

Embodiments of systems and methods of operating a vehicle include operating at least one fuel cell stack, whereupon a heat exchanger for the at least one fuel cell stack counter-balances heat therefrom with heat rejected therefrom, and operating a water system to pump water from the at least one fuel cell stack into a water reservoir. Moreover, in response to high water levels in the water reservoir, the embodiments include increasing electrical energy loads on at least one battery operable to store electrical energy from the at least one fuel cell stack, operating the at least one fuel cell stack for higher output, whereupon the heat exchanger under-balances heat therefrom with heat rejected therefrom, and operating the water system to apply water from the water reservoir onto the heat exchanger, whereupon the heat exchanger restoratively counter-balances heat therefrom with heat rejected therefrom.

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Long Beach, CA, United States of America

Daniel Charles Folick