Convion Oy

Wartsila Finland Oy

Kim Åström

Matti Noponen

Tuomas Hakala

Timo Kivisaari

Marko Laitinen

Topi Korhonen

Tero Hottinen

Matias Halinen

Toni Ollikainen

A start-up transition process is disclosed for a fuel cell system operation state, which includes utilization of predefined first and second temperature limits for the fuel cells, specifying a low temperature operating state of cells below the first limit, at which presence of carbonaceous species at the cells is precluded, a transition temperature range of cells above the first and below the second limit at which fuel flow supply is initiated to the fuel system in a mixture with air, combined with anode tail gas recirculated at a recirculation rate over 70, and an intermediate temperature operating state of the cells above the second temperature limit, at which free oxygen at the anodes.

Transition arrangement and process of a fuel cell system operation state

A control arrangement in a fuel cell system for producing electricity with fuel cells, the fuel cell system including means for recirculating fuel through the anode sides of the fuel cells, and at least one system controller in a control processor for controlling the operation of the fuel cell system. The control arrangement includes means for performing a substantially asynchronous chemical reaction rates calculation process of at least one of fuel composition and fuel flow rate to accomplish information in a substantially iterative process on at least recirculation ratio of the fuel recirculation through anodes and means for generating, in a substantially synchronous process with the system controller process, fuel utilization (FU) information and Carbon formation information by utilizing the latest available recirculation ratio information provided by said asynchronous process.

Control arrangement and method in fuel cell system

An exemplary arrangement and method for controlling operating conditions of a fuel cell device are disclosed. The fuel cell device having plural fuel cells, each including an anode side, a cathode side, an electrolyte between the anode side and the cathode side, and being arranted in a stack. The control arrangement includes at least one controllable electrical heater configured to produce controllable heat quantities, at least two controllers that control fuel cell quantities including at least a portion of air flowing to the fuel cells and heat applied to the stack environment. The controllable heat quantities and controllable fuel cell quantities are controlled to meet a target value. The fuel cell device includes a low level high speed controller configured to control at least one controllable electrical heater to operate the heater as a buffer for excess energy of the fuel cell device.

Method and arrangement to control operating conditions in fuel cell device

Exemplary systems and methods for adjusting current values in a fuel cell system for producing electricity with fuel cells, include drawing major part of the current from at least one serial connection. An adjusting circuit adjusts current values by drawing or supplying current of at least one stack of individual fuel cell stacks or current of at least one group of the groups of stacks within the serial connection. The adjusting circuit is integrated with the at least one stack of individual fuel cell stacks or with the at least one group of the groups of stacks. Compensation current of the at least one stack or group is a small percentage of a major part of the current in the serial connection of stacks.

Method and arrangement for improved controllability of fuel cell stacks

An arrangement for improved operability of a high temperature fuel cell device at higher fuel cell voltage values than nominal voltage values, each fuel cell in the fuel cell device including an anode side, a cathode side, and an electrolyte between the anode side and the cathode side, and the arrangement includes means for determining temperature information of the fuel cells and main power converter for loading fuels cells at least up to their rated power level. The arrangement includes a non-isolating pre-regulator for reducing the fuel cell voltage to a voltage level useable for the main power converter at least at substantially low power levels in start-up and low current load situations when the fuel cell voltage is significantly higher than in nominal operation conditions, the pre-regulator being located between the fuel cells and the main power converter, and the arrangement includes bypass means for bypassing the pre-regulator at substantially high current loads when the fuel cell voltage has decreased to the voltage level suitable for an input voltage of the main power converter.

Method and arrangement for improved operability of a high temperature fuel cell system

An offset control arrangement is disclosed for controlling voltage values in a fuel cell system including an anode side, a cathode side and an electrolyte between the anode side and the cathode side. The fuel cell system can include at least one fuel cell array of at least two fuel cells, and at least one load for performing load function. The offset control arrangement can include voltage monitoring for monitoring an input voltage of the load, a control processor for processing the monitoring information, and at least one offsetting source in serial connection to the at least one fuel cell array, with a power level of the offsetting source being substantially low compared to the power level of the fuel cell array, and the offsetting source being arranged to perform at least unidirectional shifting of fuel cell array output voltage.

Offset control arrangement and method for controlling voltage values in a fuel cell system

A method is disclosed for producing electrical current by a fuel cell device, which inputs electrical current to an electrical network. A fuel cell device can be arranged to be parallel connected to the electrical network. A phase reference signal can be utilized in the inputting of the electrical current, and electrical current inputted to electrical network can be current controlled by a power transformer having a power stage. The fuel cell device can be switched off from the electrical network when a malfunction occurs in the electrical network. The fuel cell device can be changed, using the phase reference signal, to the switched off operation mode for performing voltage controlled operation of the power transformer. A controllable load can be used for maintaining a power stability between the voltage controlled power transformer and other parts of the fuel cell device. When the malfunction has vanished, the fuel cell device can be changed, using the phase reference signal, to a switched on operation mode for performing current controlled operation of the power transformer.

Fuel cell device and method for feeding electrical current to electrical network

A method is disclosed for monitoring galvanic isolation of a fuel cell device. At least one stack of fuel cells and at least one load circuit for fuel cells are arranged to an electrically freely floating configuration towards at least one structure near fuel cells. A controlled switching is performed via at least two switching points to at least one measurement element having known impedance in connection to the at least one structure. Measurements are performed from the measurement element to form voltage information. The voltage information and at least voltage information between switching points are processed to check floatages of fuel cells in relation to said at least one structure.

Arrangement and method for monitoring galvanic isolation of fuel cell device

Exemplary embodiments are directed to a fuel cell system that is fed fuel and provided information on the fed fuel. The system generates information about fuel utilization in the fuel cells and oxygen to carbon ratio (O/C ratio) in the fuel cell system process and includes features for controlling a loading of the fuel cells. The fuel cell system also includes a first closed loop controller for controlling the feeding of fuel by taking into account the fuel utilization information as process feedback information, and by implementing a constraint function taking control of O/C ratio by restricting output of the first controller when said O/C ratio deviates from an allowed range, and a second controller for controlling active fuel cell loading by implementing a constraint function taking control of fuel utilization restricting output of the second controller when said fuel utilization deviates from an allowed range.

Growing community of inventors

Kirkkonummi, Finland

Kim Åström