Abstract: A method for providing calibration and synchronization pulses in a pulse width modulation (PWM) signal including cell voltage measurement pulses, where the calibration pulses are four calibration pulses having a pattern of a narrow width high voltage pulse followed by a wide width low voltage pulse followed by a narrow width high voltage pulse followed by a wide width low voltage pulse that has a very low probability of occurring in a practical fuel cell system. The method modulates a combined sequence of the voltage measurement signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

Abstract: Provided is a fuel cell system including: a wetness detecting section for detecting a wetness of a fuel cell stack; a target SR setting section for setting a target SR of the fuel cell stack based on the wetness; a smallest SR setting section for setting, based on a load, a smallest SR necessary to prevent flooding of the fuel cell stack; and an SR control section for performing control so that an actual SR becomes temporarily larger than the smallest SR when the target SR is smaller than the smallest SR.

Abstract: The patent relates to fuel cell systems and controlling fuel cell systems. One fuel cell system includes at least one fuel cell stack that includes multiple different serially arranged cells. The system also includes at least one component configured to effect an operating environment of the at least one fuel cell stack. The system further includes a controller configured to operate the at least one component at a primary control point relating to one or more parameters of the operating environment. The controller is further configured to temporarily adjust the at least one component to a secondary control point relating to the one or more parameters. The controller can then re-adjust the at least one component to the primary control point. The fuel cell system can achieve greater overall performance than can be obtained without the adjusting and re-adjusting.

Abstract: The present invention concerns an electrochemical system (100) including a stack of series connected electrochemical units (102). The system is controlled by a control circuit (104) and includes a plurality of differential amplifiers (114), each connected by two inputs to the terminals of an electrochemical unit, in order to supply a voltage representative of the potential difference present between the terminals of said electrochemical unit. Each representative voltage is sent to a control unit (106) arranged for converting said representative voltage into a numerical value transmitted to the control circuit. The system further includes, between each differential amplifier and the control unit, a buffer means (116) controlled by the control circuit. The buffer means is capable of saving the voltage representative of the potential difference present between the terminals of the electrochemical unit to which it is connected. The voltage is saved simultaneously by all of the buffer means.

Abstract: A fuel cell assembly according to an exemplary aspect of the present disclosure includes, among other things, a first fuel cell stack in series with a variable resistor and a second fuel cell stack in parallel with the first fuel cell stack and in series with a contactor. A resistance level of the variable resistor is adjusted in response to deactivating the contactor.

Abstract: There are provided a fuel cell system capable of reducing power consumption by inhibiting an unnecessary operation of a DC-DC converter, and a power control method therefor.

Abstract: A fuel cell system is provided that includes a fuel cell stack, an air pump, a first convertor, a motor, and an ECU for controlling the air pump and the first convertor based on the target voltage and the switching voltage of the single cell. The ECU executes the first mode such that the actual voltage of the single cell corresponds to the target voltage, when the target voltage is equal to or less than the switching voltage, while the ECU executes the second mode such that the actual voltage of the single cell is kept at the switching voltage, when the target voltage is more than the switching voltage. Further, the ECU executes the second mode thereby to change the actual current of the single cell.

Abstract: In a fuel cell system including a fuel cartridge and a fuel supply module, the fuel cartridge includes at least two ports, wherein a first port from among the at least two ports is a fuel inlet port and a second port from among the at least two ports is a fuel outlet port. The fuel cartridge may also include a fuel pouch or the fuel cartridge itself may be the fuel pouch. The fuel supply module may include a fuel circulation structure that circulates the fuel before the fuel is supplied to the stack. The fuel cell system may be equipped with an electronic apparatus and serve as a source of power.

Abstract: A fuel cell system according to the present invention comprises a control apparatus which performs performance restoration processing for a catalyst layer by decreasing the output voltage of a fuel cell to a predetermined voltage. When an oxide film formed on the catalyst layer during power generation of the fuel cell contains, in addition to a first oxide film that can be removed by decreasing the output voltage of the fuel cell to a first oxide film removal voltage, a second oxide film that can be removed by decreasing the output voltage of the fuel cell to a second oxide film removal voltage which is lower than the first oxide film removal voltage, the control apparatus estimates the amount of the second oxide film and performs performance restoration processing with a set voltage being equal to or lower than the second oxide film removal voltage only when it determines that the estimated amount exceeds a predetermined amount A.

Abstract: The disclosure is directed at a method and apparatus for controlling fuel cell operating conditions. The apparatus includes a set of sensors for monitoring the fuel cell operating conditions and a processing unit, in communication with the set of sensors for determining when the fuel cell operating conditions are outside of an acceptable range. When it is determined that the fuel cell operating conditions are outside of the acceptable range, an electrolyzer is activated to electrolyze waste liquid water or water vapor to assist in controlling the fuel cell operating conditions.

Abstract: A fuel cell system includes an air supply flow path configured to supply the air to a fuel cell, a reed valve provided in the air supply flow path, an air exhaust flow path configured to allow the air discharged from the fuel cell to flow therethrough, a pressure regulating valve provided in the air exhaust flow path and configured to adjust back pressure of the air supplied to the fuel cell, a bypass flow path configured to connect an upstream section of the air supply flow path upstream of the reed valve with the air exhaust flow path, and a bypass valve provided in the bypass flow path and configured to open and close the bypass flow path. The fuel cell system reduces the opening of the pressure regulating valve with supplying the air to the fuel cell in the closed position of the bypass valve, so as to increase the pressure of the air upstream of the pressure regulating valve, and subsequently opens the bypass valve.

Abstract: A health monitoring system for a fuel cell stack using current fuel cell architecture to enable the electronic control unit (ECU) to continue to monitor the health of the fuel cell stack despite a component failure. The system uses an embedded measurement module (EMM) connected to a group of fuel cells in the fuel cell stack to monitor the health of that group of fuel cells. The EMM produces a pulse width modulation signal that is sent to the ECU. A total voltage value for the group of fuel cells is embedded into the calibration signal or end of frame sequence. The ECU uses an algorithm to determine a missing voltage of at least one fuel cell in the event of the component failure of that fuel cell by adding up the cumulative value for each fuel cell reporting their voltage and subtracting that value from the total voltage value found in the end of frame sequence.

Abstract: The disclosed embodiments relate to the design of a portable and cost-effective fuel cell system for a portable computing device. This fuel cell system includes a fuel cell stack which converts fuel into electrical power. It also includes a fuel source for the fuel cell stack and a controller which controls operation of the fuel cell system. The fuel system also includes an interface to the portable computing device, wherein the interface comprises a power link that provides power to the portable computing device, and a bidirectional communication link that provides bidirectional communication between the portable computing device and the controller for the fuel cell system.

Abstract: A fuel cell system includes a reforming unit, a carbon-monoxide decreasing unit, a fuel cell, a burner unit, and a raw gas supply device. At a start-up operation of the fuel cell system, an amount of raw gas supplied from the raw has supply device is adjusted according to an amount of a desorbed raw gas desorbed out of components of the raw gas adsorbed to at least one of the reforming catalyst and a carbon monoxide decreasing catalyst such that a ratio of an amount of the combustion air to an amount of the raw gas in the burner unit falls within a predetermined range.

Abstract: A fuel cell system of the present invention includes: a fuel cell supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell; an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell; an aftercooler cooling the oxidizing gas supplied to the fuel cell by heat exchange with a coolant; an oxidizing gas temperature detector detecting temperature of the oxidizing gas; and a coolant circulation controller starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell, and a circulation timing and flow rate of the coolant for the aftercooler are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell to generate electricity at cold start-up.

Abstract: A fuel cell system 10 removes water retaining in a cathode catalyst layer 217 in a fuel cell 20, after a start-up of the fuel cell 20 and before feed of coolant to the fuel cell 20.

Abstract: The progress of activation of a fuel cell is appropriately transmitted in accordance with the rise of the temperature of the fuel cell, and an estimated time till the completion of the activation is displayed with higher accuracy. To realize this, the current percentage of a fuel cell temperature is displayed on a gauge (G) which displays, as a starting point, the temperature of the fuel cell at the start of the activation and which displays, as an end point, the temperature of the fuel cell at the completion of the activation. The percentage of the temperature is displayed as the estimated time till the completion of the activation, whereby an adverse effect due to a low accuracy in the case of the estimation of the time is eliminated. When the fuel cell is activated for a failure check, the percentage of an actually elapsed time with respect to a time required to complete the failure check may be displayed on the gauge (G).

Abstract: A method for assembling an electrochemical cell stack may include arranging a plurality of electrochemical cells into an electrochemical cell stack, the electrochemical cell stack including at least a first substack and a second substack; connecting the first substack and second substack such that reactant fluid flows in series from the first substack to the second substack; and coupling the first substack to a first electrical control device such that the first electrical control device selectively electrically reconfigures the first substack to operate in series and in parallel with the second substack.

Abstract: Disclosed herein is an apparatus and method for controlling a fuel cell system. The apparatus includes a main power conditioning system which supplies output of normal stacks among a plurality of fuel cell stacks to a load, a sub-power conditioning system which supplies output of one or more deteriorated stacks among the fuel cell stacks to a load, a switching unit which changes a target to which output of each of the fuel cell stacks is connected, and a control unit which senses conditions of each of the fuel cell stacks and controls the switching unit. The apparatus prevents deterioration in performance of some stacks from affecting the other normal stacks. Furthermore, the deteriorated fuel cell stacks are separately controlled to provide power to a sub-load through a sub-power conditioning system.

Abstract: A method of operating a fuel cell system includes characterizing the fuel or fuels being provided into the fuel cell system, characterizing the oxidizing gas or gases being provided into the fuel cell system, and calculating at least one of the steam:carbon ratio, fuel utilization and oxidizing gas utilization based on the step of characterization.

Abstract: A system and method for controlling an output of a dynamic fuel cell is provided. A dynamic fuel cell has a membrane wherein a dimension of the membrane is variable during operation of the dynamic fuel cell in response to a control signal from an intelligent controller. By varying the dimension of the membrane, the output voltage of the dynamic fuel cell can be altered. An intelligent controller is provided that can measure a number of outputs and input parameters of the dynamic fuel cell and approximate input parameters using the measured values to adjust the input of the dynamic fuel cell to the approximated values.

Abstract: A solid oxide fuel cell capable of maintaining performance over a long time period by appropriately changing fuel cell module operating conditions. The present invention is a solid oxide fuel cell (1), having a fuel cell module (2), a fuel supply device (38), an oxidant gas supply device (45), and a controller (110) for controlling the amount of fuel supplied from the fuel supply device; the controller is furnished with a degradation determining circuit (110a) for determining degradation in the fuel cell module and a degradation response circuit (110b) for changing fuel cell module operating conditions based on the degradation determination by the degradation determining circuit; the degradation determination stores fuel cell module operating results arising from the operating conditions changed by the degradation response circuit, and executes further degradation determination based on the stored operating results.

Abstract: This invention provides an improved forklift fuel cell supply system consists of enclosure 90 and the fuel cell system 100, DCDC converting unit 2, contactor 3, energy storage device 4, controller 7 provided in the said enclosure 90, which also consists of the power supply output end 5 provided outside the said enclosure 90 and the operation control unit 6, electric isolation board 901, hydrogen storage system, filling valve 95 provided in the said enclosure 90, in which the said contactor 3 is a normal open type high-current contactor, the said DCDC converting unit 2 includes the DCDC converter 21 and high-power diode 22 connecting with it. This invention is compact in structure and facilitates such work as system installation, overhaul and maintenance, etc.

Abstract: This disclosure is directed to a self-powered internal medical device. An example device may comprise at least an energy generation module and an operations module to at least control the energy generation module. The energy generation module may include a structure to capture certain molecules in the organic body based at least on size, the structure including a surface of the device in which at least one opening is formed. The at least one opening may be sized to only capture certain molecules. The operations module may initiate oxidation reactions in the captured molecules to generate current for device operation or for storage in an energy storage module. Thermoelectric generation circuitry in the energy generation module may also use heat from the reaction to generate a second current. The operations module may control operation of a sensor module and/or communication module in the device based on the generated energy.

Abstract: An electrochemical cell stack system may include a plurality of cell stacks fluidly connected by a plurality of first conduits to form a loop of cell stacks. At least one first valve may be located on each first conduit and may be capable of a closed configuration and an open configuration. Each of the cell stacks may have an input end for receiving a first fluid and an output end for discharging a second fluid. The system may deliver the first fluid from the fluid source to the input end of a first cell stack of the plurality of cell stacks via a first input line of a plurality of input lines and may receive the second fluid from the output end of a second cell stack of the plurality of cell stacks via a first output line of a plurality of output lines.

Abstract: A method of using a proton exchange membrane fuel cell, composed of a polymer membrane and electrodes present on either side of the membrane, includes at least one step of reversing the functioning of the cell during use.

Abstract: A fuel cell system includes a fuel cell, a multiphase voltage conversion device with N-phases (N being an integer equal to or larger than two) that is connected to the fuel cell, a control signal generation portion that generates control signals to control each phase of the multiphase voltage conversion device by superimposing a control waveform for measuring impedance on a voltage indicating an output target voltage of the multiphase voltage conversion device and sequentially outputs the control signals corresponding to N phases with a predetermined phase difference to the multiphase voltage conversion device, and an impedance calculation portion that measures a current and a voltage of the fuel cell on cycles corresponding to N predetermined sampling frequencies having a phase difference equal to the predetermined phase difference and calculates an impedance of the fuel cell based on the measured current and the measured voltage.

Abstract: A system and method for reducing the frequency of stack stand-by mode events, if necessary, as a fuel cell stack ages and experiences lower performance. The method determines an irreversible voltage loss of the fuel cell stack at predetermined time intervals and determines a stack voltage degradation variable based on the irreversible voltage loss. The method also determines if the stack voltage degradation variable indicates that the fuel cell stack will not meet predetermined stack end-of-life voltage requirements and calculates a maximum allowed voltage degradation rate of the fuel cell stack. The method calculates a maximum number of stand-by mode events per unit time that can be allowed to prevent the stack from exceeding the maximum allowed degradation rate and controls the number of stand-by mode events based on the calculated maximum number of stand-by mode events.

Abstract: The present disclosure is directed to a method for tuning the performance of at least one electrochemical cell of an electrochemical cell stack. The method includes supplying power to an electrochemical cell stack. The electrochemical cell stack includes a plurality of electrochemical cells. The method further includes monitoring a parameter of at least one electrochemical cell and determining if an electrochemical cell becomes impaired. The method also includes diverting a fraction of the current flow from the impaired electrochemical cell during operation of the electrochemical cell stack.

Abstract: A fuel cell system and a method of operating the same. The fuel cell system in particular includes an air discharge part provided on the anode of a fuel cell, and a controller that is configured to measure a purging period of recirculated hydrogen and an operating temperature of the fuel cell, and operate the air discharge part based on the measured values to prevent the anode from becoming poisoned due to the emission of CO gases.

Abstract: Provided is a method for shutting down an indirect internal reforming SOFC, in which a hydrocarbon-based fuel is reliably reformed, and the oxidative degradation of the anode can be prevented by a reformed gas.

Abstract: A method for controlling relative humidity (RH) of a cathode side of a fuel cell stack in a fuel cell system that includes an RH sensor on a cathode inlet line for providing an RH signal indicative of the RH of cathode inlet air. If the RH sensor is providing a valid RH signal, the RH signal is calculated as an RH average of the cathode inlet air. When the RH sensor is not providing a valid RH signal, the calculated RH average is utilized to control the cathode inlet air RH. If the RH sensor is not providing a valid signal during start-up, then the stack power is temporarily set at an optimum level for a known cathode inlet air RH.

Abstract: An object of the present invention is to provide a fuel cell system and a mobile body capable of restraining freeze in an air cleaner. The fuel cell system includes an air cleaner for cleaning the air to be supplied to a fuel cell and a heater for heating the air cleaner. The air cleaner can be alternatively heated by supplying a refrigerant in a refrigerant piping system to the air cleaner instead of using the heater.

Abstract: Even in a fuel cell system which performs scavenging processing after the power generation of a fuel cell is stopped, the operation time for when a battery is being operated can be increased. When determining that the condition of running out of gas occurs based on a sensor value of a pressure sensor, a control unit stops the power generation of the fuel cell. The control unit, for example, shortens the time required for scavenging processing and then performs the scavenging processing. On the other hand, when determining that the condition of running out of gas does not occur and when the power generation of the fuel cell should be stopped, the control unit stops the power generation and then performs normal scavenging processing.

Abstract: Disclosed are an apparatus for portable fuel cell and an operation method thereof, wherein stabilization state after initial operation can be determined using OCV.

Abstract: The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance metric.

Abstract: A system for delivering an input fuel stream to a fuel cell stack to generate electrical current and to discharge an unused fuel stream is provided. A supply produces a supply fuel stream. An ejector combines a purged fuel stream and the supply fuel stream and controls the flow of the input fuel stream to the fuel cell stack. A purging arrangement receives the unused fuel stream which includes impurities and purges the impurities from the unused fuel stream to generate the purged fuel stream. A bypass valve is capable of delivering the purged fuel stream to the ejector. A blower is capable of delivering the purged fuel stream to the ejector. A controller controls one of the bypass valve and the blower for delivering the purged fuel stream to the ejector based on the amount of electrical current generated by the fuel cell stack.

Abstract: A gas detection system is configured to detect a preset gas in a predetermined space. The gas detection system includes a gas concentration detector constructed to detect a gas concentration of the preset gas, a recording assembly, a notification module, and a decision module. When the gas concentration detected by the gas concentration detector is higher than a preset first reference value, the decision module controls the notification module to give notice. When the detected gas concentration is higher than a preset second reference value but is lower than the preset first reference value, on the other hand, the decision module controls the notification module to give no notice but record a specific piece of information into the recording assembly. This arrangement of the gas detection system enables the user to readily detect deterioration of a device utilizing a fuel, for example, fuel cells.

Abstract: In a hydrogen concentration measurement device that employs a proton conducting electrolyte membrane, more stable measurement of hydrogen concentration that is less susceptible to temperature and humidity state of measurement target gas becomes possible.

Abstract: A fuel cell system includes: a fuel cell including a cell laminate; an estimating unit for estimating a residual water content distribution in the reactant gas flow channel in a cell plane of each of the single cells and a moisture content distribution in the electrolyte membrane in consideration of water transfer through the electrolyte membrane between the anode electrode and the cathode electrode; and an operation control unit for limiting an electric current drawn from the fuel cell when a residual water content in the reactant gas flow channel estimated by the estimating unit is equal to or above a predetermined threshold.

Abstract: A method and apparatus for improving the water balance in a power unit by providing the exhaust gas from the cathode side of the fuel cell as a feed gas to the combustion system condensing at least a portion of water present in the effluent from the combustion system in a condenser, and then transferring water vapor from the uncondensed portion of the effluent from the condenser to the gas fed to the cathode side of the fuel cell. Water from the exhaust gas from the cathode side of the fuel cell is either captured in the condenser, or is reused in the feed gas of the cathode side of the fuel cell. By humidifying the air fed into system with the water vapor present in the exhaust gas, water is not lost from the system. Instead, the air is being fed into the system is humidified with this water, which in turn allows the humidifier to operated at higher temperatures and/or use smaller radiators and fans and/or draw less parasitic power, thereby increasing overall system efficiency.

Abstract: A fuel cell system is provided having at least one fuel cell including an oxidant electrode, a fuel electrode, and an electrolyte membrane interposed between the oxidant electrode and the fuel electrode. The fuel cell system includes a temperature detector which detects a temperature of the fuel cell and a controller which operates the fuel cell, controls a potential of the oxidant electrode, and determines whether to perform a performance recovery operation in which an impurity on the oxidant electrode is oxidized. When the performance recovery operation is to be performed, the controller controls the potential of the oxidant electrode to be a desired potential based on the temperature detected by the temperature detector.

Abstract: The present invention detects a failure in an FC converter. A target voltage determination section determines an output target voltage for a fuel cell. A superimposition signal generation section generates a predetermined reference signal to be superimposed onto the output target voltage. A voltage command signal generation section generates a voltage command signal by superimposing the reference signal onto the output target voltage. A frequency characteristics calculation section calculates the frequency characteristics of the reference signal component superimposed on the output voltage of the fuel cell. A failure judgment section judges that a failure occurs in the FC converter if a value of the calculated frequency characteristics is less than the lower limit threshold value of an allowable range established based on reference characteristics.

Abstract: A fuel cell system which is capable of reducing deterioration of fuel cells includes a cell stack, a CPU, a voltage detection circuit, a current detection circuit, an external air temperature sensor, a humidity sensor, a concentration sensor and sonars. The CPU obtains a volume of a garage, an amount of temperature change, an amount of humidity change and an amount of methanol concentration change in external air, as well as an amount of output change in the cell stack based on detection results from the voltage detection circuit, the current detection circuit, the external air temperature sensor, the humidity sensor, the concentration sensor and the sonars. The CPU sets first through fifth duration times based on the volume of the garage and the various amounts of changes, selects the shortest duration time, and stops power generation in the cell stack when the selected duration time has passed.

Abstract: A method for determining the health of the membranes in a fuel cell stack. The total parasitic current of the fuel cells in the stack is determined. From the total parasitic current, the shorting resistance and the cross-over parasitic current are determined. The health of the membranes is then determined from the cross-over parasitic current and the shorting resistance.

Abstract: A fuel cartridge with which liquid leakage through an air induction hole from a fuel tank is able to be prevented and safety is able to be improved is provided. Switching drive for opening and closing an air induction hole 12 is performed by a valve 13 capable of controlling the switching drive according to a control signal. Thereby, air introduction to a fuel tank 100 containing a fuel is able to be controlled. Thus, for example, at the time of high temperature or fuel disorder, by closing the air induction hole 12 by the valve 13, fuel leakage from the fuel tank through the air induction hole of an existing check valve is able to be prevented, and safety is able to be improved.

Abstract: To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device (1) for generating electricity, having a fuel cell module (2); a reformer (20), a fuel supply device (38); a water supply device (28), a generating oxidant gas supply device (45), and a controller (110) for controlling the fuel supply device and water supply device at the time of startup when the fuel cell module solid oxide fuel cell unit is raised to a temperature at which electrical generation is possible, inducing in the reformer a SR in which only a steam reforming reaction occurs; wherein the control section maintains the fuel supply flow rate in the SR immediately prior to electrical generation at an electrical generation standby fuel supply flow rate determined according to solid oxide fuel module usage conditions and smaller than the fuel supply flow rate at the time of SR startup.

Abstract: A fuel cell system capable of measuring AC impedance comprises: power generation stabilizing means for stabilizing power generation in a fuel cell, and impedance measuring means for measuring the AC impedance after power generation in the fuel cell has been stabilized. Since the AC impedance in a low frequency range is measured after power generation in the fuel cell is stabilized, no external disturbance occurs during measurement, and the AC impedance can be measured with a high degree of precision. Thus, a fuel cell system and a measuring method with which AC impedance can be measured with a high degree of precision can be provided.

Abstract: A method for managing the operation of a hybrid continuous current supply, said supply including a fuel cell stack a battery and a DC/DC converter including an input and an output, the converter input being connected to the output of the fuel cell stack and the output being connected to a variable load in parallel to the battery, the fuel cell stack being formed of a plurality of electrochemical cells adapted to produce electricity from a fuel and an oxidising gas.

Abstract: Systems and methods to control fuel cell stack pressure through a cathode backpressure valve. A flow offset value is used as a capacitance term during transient operational conditions to account for discrepancies between the stack flow setpoint and the actual stack flow. The capacitance term is based on operational parameters, including stack pressure changes, stack coolant temperature and stack volume. The additional flow produced by the capacitance terms may be fed, along with pressure drop models and a valve position model to provide a more accurate prediction of valve position.