Abstract: A fuel cell system is disclosed, which includes a fuel cell stack coupled to a load for providing power, a gas delivery system coupled to the fuel cell stack for providing fuel and oxygen to the fuel cell stack and a control system. The control system includes a forward controller for generating a desired control instruction signal based on a command from the load, and a correction controller for generating a control correction signal to avoid violating operational constraints of the fuel cell stack based on at least one measured signal from the fuel cell system. The control system generates a control signal based on the desired control instruction signal and the control correction signal, and controls the gas delivery system based on the generated control signal to ensure the fuel cell stack is operated within safe operating limits. A method for controlling the fuel cell system is also disclosed.

Abstract: A system (100, 200) is presented. The system includes a fluid lifting device (102, 202) located inside a well (106, 206), and comprising an electrical motor (108, 208), a three phase cable (114, 214) for coupling the fluid lifting device to a power source (112, 212), at least one high sensitivity differential current transformer (104, 203, 204) for generating imbalance signals (128, 227) representative of an imbalance current in at least one of the electrical motor and the three phase cable, wherein the at least one high sensitivity differential current transformer is disposed such that the at least one high sensitivity differential current transformer surrounds at least a portion of the three phase cable, and a processing subsystem (136, 236) for monitoring the health of at least one of the fluid lifting device and the three phase cable based on the imbalance signals.

Abstract: A system (100, 200) is presented. The system includes a fluid lifting device (102, 202) located inside a well (106, 206), and comprising an electrical motor (108, 208), a three phase cable (114, 214) for coupling the fluid lifting device to a power source (112, 212), at least one high sensitivity differential current transformer (104, 203, 204) for generating imbalance signals (128, 227) representative of an imbalance current in at least one of the electrical motor and the three phase cable, wherein the at least one high sensitivity differential current transformer is disposed such that the at least one high sensitivity differential current transformer surrounds at least a portion of the three phase cable, and a processing subsystem (136, 236) for monitoring the health of at least one of the fluid lifting device and the three phase cable based on the imbalance signals.

Abstract: A fuel cell system is disclosed, which includes a fuel cell stack coupled to a load for providing power, a gas delivery system coupled to the fuel cell stack for providing fuel and oxygen to the fuel cell stack and a control system. The control system includes a forward controller for generating a desired control instruction signal based on a command from the load, and a correction controller for generating a control correction signal to avoid violating operational constraints of the fuel cell stack based on at least one measured signal from the fuel cell system. The control system generates a control signal based on the desired control instruction signal and the control correction signal, and controls the gas delivery system based on the generated control signal to ensure the fuel cell stack is operated within safe operating limits. A method for controlling the fuel cell system is also disclosed.

Abstract: A combustion optimization system is disclosed. The system includes a boiler having a plurality of zonal locations, a sensor grid comprising a plurality of sensors, a sensor validation device and an optimizing controller. The plurality of sensors are configured to provide a plurality of sensor signals and the plurality of sensor signals are indicative of measurements of the respective zonal locations. The sensor validation device is configured for receiving the plurality of sensor signals from the plurality of sensors and generating validated sensor signals of the respective sensors based on the plurality of received sensor signals and pre-determined correlations among the plurality of received sensor signals. The optimizing controller is configured for optimizing at least one operating parameter of the boiler based on the validated sensor signals of the respective sensors. A combustion optimization method is also disclosed.

Abstract: Systems and methods are disclosed for on-line monitoring of the condition of the stator insulation of an AC motor or an electric generator. In certain embodiments, the system includes a transformer surrounding each pair of input and output cables associated with a given phase of power provided to the AC motor or generated by the electric generator. In another embodiment, a transformer surrounds the three input cables (for an AC motor) or the three output cables (for an electric generator) that correspond to phases of the AC motor or electric generator. In both embodiments, the transformers generate voltages that may be used to monitor leakage currents associated with the cables. A microcontroller monitors the voltages generated by the transformers and determines the condition of the stator insulation of the AC motor or the electric generator based on the voltages.

Abstract: A current transformer is provided. The current transformer comprises an inner magnetic core having a central opening, an outer sense core circumscribing the inner magnetic core, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the inner magnetic core, and one or more coils disposed on the inner magnetic core, the outer sense core, or both, in a magnetically balanced configuration relative to a magnetic neutral axis of the inner magnetic core.

Abstract: Systems and methods are disclosed for on-line monitoring of the condition of the stator insulation of an AC motor or an electric generator. In certain embodiments, the system includes a transformer surrounding each pair of input and output cables associated with a given phase of power provided to the AC motor or generated by the electric generator. In another embodiment, a transformer surrounds the three input cables (for an AC motor) or the three output cables (for an electric generator) that correspond to phases of the AC motor or electric generator. In both embodiments, the transformers generate voltages that may be used to monitor leakage currents associated with the cables. A microcontroller monitors the voltages generated by the transformers and determines the condition of the stator insulation of the AC motor or the electric generator based on the voltages.

Abstract: A current transformer is provided.

Abstract: A partial discharge analysis (PDA) coupling device is provided. In one embodiment, a device includes: a connector electrically connecting a first coupling capacitor and a second coupling capacitor; a first conductive rod for electrically connecting the first coupling capacitor to a high voltage input; a second conductive rod for electrically connecting the second coupling capacitor to ground; a current transformer substantially surrounding a portion of the second conductive rod, the current transformer configured to generate a pulse signal; and a reference signal generator adjacent to the current transformer configured to generate a reference signal in phase with the pulse signal.

Abstract: A method of monitoring a capacitor bank comprising a plurality of capacitor strings connected in parallel, each capacitor string comprising a plurality of capacitors connected in series is provided. The method includes energizing the capacitor bank. The method includes determining dissipation factors of each of the plurality of the capacitor strings. The method further includes comparing each of the determined dissipation factors with an expected dissipation factor and estimating a health state of the plurality of the capacitor strings based, at least in part, on the comparison of the determined and expected dissipation factors.

Abstract: A current transformer is provided. The current transformer comprises an inner magnetic core having a central opening, an outer sense core circumscribing the inner magnetic core, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the inner magnetic core, and one or more coils disposed on the inner magnetic core, the outer sense core, or both, in a magnetically balanced configuration relative to a magnetic neutral axis of the inner magnetic core.

Abstract: An electrostatic filter assembly configured to be installed in equipment for removing particulate matter entrained within a gas stream. The filter assembly functions in the removal and collection of the particulate matter from the gas stream. The equipment for removing particulate matter includes a high voltage discharge electrode for imparting an electric charge to the particulate matter whereby an electrical field is produced at the filter assembly. The filter assembly includes a filter element and a supporting structure for the filter element. The supporting structure is configured to establish at the filter assembly, under the operating conditions of the equipment for removing particulate matter, an electrical field having an intensity that produces no more than a selected amount of degradation at the filter element during operation of the equipment for removing particulate matter. Also a method of manufacturing such an electrostatic filter assembly.

Abstract: A partial discharge analysis (PDA) coupling device is provided. In one embodiment, a device includes: a connector electrically connecting a first coupling capacitor and a second coupling capacitor; a first conductive rod for electrically connecting the first coupling capacitor to a high voltage input; a second conductive rod for electrically connecting the second coupling capacitor to ground; a current transformer substantially surrounding a portion of the second conductive rod, the current transformer configured to generate a pulse signal; and a reference signal generator adjacent to the current transformer configured to generate a reference signal in phase with the pulse signal.

Abstract: A current transformer is provided. The current transformer includes a magnetic core having a central opening, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the magnetic core, one or more coils disposed on the magnetic core along a magnetic neutral axis of the magnetic core and one or more coils disposed on the magnetic core along a reference axis, wherein the reference axis is substantially perpendicular to the magnetic neutral axis.

Abstract: A varistor pre-assembly includes an electrode formable structure and a sinterable mass proximate to electrode formable structure. The electrode formable structure includes a material having a melting point that may be within a determined temperature relative to a sintering temperature of the sinterable mass. The electrode formable structure and sinterable mass may form a varistor when simultaneously subjected to the sintering temperature, which may be less than about 1000 degrees Celsius. A method to make the article is also provided.

Abstract: A method of detecting partial discharge associated with at least a portion of an electrical system, wherein the electrical system includes at least one electrical machine electrically coupled within the electrical system, includes generating an electromagnetic field within the electrical machine. The method also includes collecting partial discharge data from at least a portion of the electrical system. The method further includes determining a first partial discharge inception voltage (PDIV) value of at least a portion of partial discharge activity within the electrical system. The method also includes generating at least one trending comparison of the first PDIV value and at least one second PDIV value of at least a portion of partial discharge activity within the electrical system. The method further includes outputting the results.

Abstract: An electrostatic filter assembly configured to be installed in equipment for removing particulate matter entrained within a gas stream. The filter assembly functions in the removal and collection of the particulate matter from the gas stream. The equipment for removing particulate matter includes a high voltage discharge electrode for imparting an electric charge to the particulate matter whereby an electrical field is produced at the filter assembly. The filter assembly includes a filter element and a supporting structure for the filter element. The supporting structure is configured to establish at the filter assembly, under the operating conditions of the equipment for removing particulate matter, an electrical field having an intensity that produces no more than a selected amount of degradation at the filter element during operation of the equipment for removing particulate matter. Also a method of manufacturing such an electrostatic filter assembly.

Abstract: A method of monitoring a capacitor bank comprising a plurality of capacitor strings connected in parallel, each capacitor string comprising a plurality of capacitors connected in series is provided. The method includes energizing the capacitor bank. The method includes determining dissipation factors of each of the plurality of the capacitor strings. The method further includes comparing each of the determined dissipation factors with an expected dissipation factor and estimating a health state of the plurality of the capacitor strings based, at least in part, on the comparison of the determined and expected dissipation factors.

Abstract: A current transformer is provided. The current transformer comprises an inner magnetic core having a central opening, an outer sense core circumscribing the inner magnetic core, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the inner magnetic core, and one or more coils disposed on the inner magnetic core, the outer sense core, or both, in a magnetically balanced configuration relative to a magnetic neutral axis of the inner magnetic core.