Abstract: Disclosed examples include power conversion systems, computer readable mediums and methods for mitigating input filter resonance, in which a controller operates an active front end (AFE) rectifier in a first mode to turn a single rectifier switching device on and off and measures a filter voltage or current signal while all of the rectifier switches are off. The controller determines a resonant frequency based on a transient response of the measured voltage or current signal, and selectively adjusts a rectifier control parameter to mitigate filter resonance based on the resonant frequency.

Abstract: Power conversion systems and methods are provided for ride through of abnormal grid conditions or disturbances, in which a system rectifier is operated in a first mode to regulate a DC voltage of an intermediate DC circuit, an inverter is operated in the first mode to convert DC power from the intermediate DC circuit to provide AC output power to drive a load. In response to detecting an abnormal grid condition, the system changes to a second mode in which the rectifier is turned off and the inverter regulates the DC voltage of the intermediate DC circuit using power from the load.

Abstract: A method for determining a degree of aging of an oxidizing catalytic converter in an exhaust system of an internal combustion engine is provided. The method comprises generating a temporary increase in carbon monoxide levels in an exhaust gas stream, monitoring subsequent oxidizing action and determining a degree of aging of the oxidizing catalytic converter as a function of the measured oxidizing action. The method further comprises measuring a temperature rise during oxidation and correlating the aging of the converter to the speed of temperature rise.

Abstract: System, apparatus and methods are provided for identifying a phase loss condition in a motor drive. In one example, a power conversion system includes an active rectifier, a switching inverter, and a controller. The controller is operative to generate rectifier switching control signals to operate the rectifier, measure AC input voltage signals and determine grid current signals. If the rectifier circuit is not in a switching mode, the controller identifies a suspected AC input phase loss condition if two of the AC input voltage signals are in phase with one another. If the rectifier is in the switching mode, the controller identifies a suspected AC input phase loss condition if the absolute value of the sum of two of the grid current signals is less than a predetermined non-zero threshold.

Abstract: Systems and methods for reducing NOx emissions are provided, comprising: adjusting an amount of water injected into an intake manifold responsive to an oxygen concentration, temperature and pressure in the intake manifold; and heating the injected water if humidity is higher than a threshold. Water injected into the intake manifold decreases the temperature of, and dilutes the oxygen content of intake gases thereby decreasing NOx emissions.

Abstract: The disclosure relates to a system and method for identifying whether a difference between measured lambda and computed lambda, based on mass air flow and mass fuel flow, is due to a drift in fuel metering or a drift in air metering. The determination is based on also measuring exhaust gas NOx using a NOx sensor. By comparing the measured NOx to modeled NOx, drift can be attributed appropriately to the air flow measurement and/or the fuel flow measurement. Appropriate correction in the calibration can be undertaken to overcome sensor drift and/or drift in the fuel injector/fuel system flow characteristics.

Abstract: Impedance detection methods and systems are presented for automatic computation of an electrical component impedance value at one or more specific frequencies of interest using quadrature voltage and current values generated by quadrature tracking filters based on sensed or measured voltage and current signals or values and a base frequency input.

Abstract: The systems and methods herein relate the operation of a particle filter which is arranged in an exhaust-gas path of an internal combustion engine, to a device for exhaust-gas aftertreatment which can be operated in accordance with the method that comprises determining a mass flow rate of an exhaust-gas flow flowing in the exhaust-gas path; and supplying ambient air into the exhaust-gas path as a function of the determined mass flow rate. By this method, the spontaneous regeneration of a particle filter within the exhaust system may be abated.

Abstract: A double fed induction generator (DFIG) converter, methods and computer readable mediums are presented in which rotor side current spikes are attenuated by selectively activating at least one series damping circuit to conduct current through a series damping circuit resistance coupled in series between one or more DFIG rotor leads and a grid side converter in response to a grid fault occurrence or a grid fault clearance, and selectively bypassing the series damping circuit resistance after activating the series damping circuit.

Abstract: An internal combustion engine has a cylinder and an exhaust-gas turbocharger comprising a compressor arranged in an intake system and a turbine arranged in an exhaust-gas discharge system. Various lines are provided for conducting gases including 1) a bypass line branching off from the inlet system downstream of the compressor so as to form an inlet-side junction, and 2) a recirculation line branching off from the exhaust-gas discharge system upstream of the turbine so as to form an outlet-side junction which opens into the bypass line. A first control element at the outlet-side junction adjusts an exhaust-gas quantity conducted through the recirculation line. A second control element at the inlet-side junction has a first position that separates the bypass line from the cylinder and connects the intake line to the cylinder, and a second position that separates the intake line from the cylinder and connects the bypass line to the cylinder.

Abstract: Described herein are methods, systems, and apparatuses for determining sag in a signal. In one example, a method of tracking sag in a signal includes, when in an initial state, monitoring for when the signal transitions to a sag state based at least on an output of a tracking filter. In response to the signal transitioning to the sag state, increasing a bandwidth of the tracking filter and, when in the sag state, monitoring for when the signal transitions to a recovering state. The method further includes, in response to the signal transitioning to the recovering state, decreasing the bandwidth of the tracking filter.

Abstract: The present disclosure describes systems and methods for recharging a storage catalyst of an internal combustion engine. A method is described, comprising: while operating an engine in a substoichiometric operating mode when the engine is under medium load and responsive to an LNT condition, assisting the engine with an electric machine connected to an engine crankshaft. The electric machine provides an auxiliary drive to assist the engine in maintaining the substantially steady state substoichiometric operating mode which may be used to reduce NOx or SOx build up in a storage catalytic convertor or to assay the condition of a storage catalytic convertor.

Abstract: The present disclosure relates to an exhaust-gas aftertreatment system for an internal combustion engine, having an exhaust line and having provided therein a filter arrangement which comprises a first particle filter element and a second particle filter element, wherein the first particle filter element is equipped with an active regeneration device for restoring its filtration performance. The disclosure furthermore relates to a method for operating an exhaust-gas aftertreatment system of said type and to the use thereof.

Abstract: A system is disclosed herein for a four-stroke internal combustion engine, the system comprising: at least two cylinders; a fuel direct injection device; a variable valve timing system; an engine controller to control spark ignition and valve timing according to load; wherein, below a lower load threshold, a first cylinder is deactivated, an injection of fuel takes place into a combustion chamber of the first cylinder and an outlet valve of the first cylinder is open during a compression stroke. Fuel injected into the deactivated cylinders may enter the exhaust tract through the open outlet valves and serve as a reducing agent therein.

Abstract: Methods and apparatus are presented for unintentional islanding detection for grid tie converters in which the phase angle disturbance is introduced by modification of grid side converter switching control signals and a mismatch of reactive power between generation and the grid load is formed upon the occurrence of unintentional islanding, where the applied phase disturbance is determined according to two pre-defined curves to form an equivalent positive feedback at different frequencies to prevent the converter from forming an island at a new stable frequency after the grid is disconnected.

Abstract: An internal combustion engine comprising a turbocharger wherein a bypass line in an exhaust gas discharge system delivers an aqueous urea reductant to an at least one SCR catalyst and a method to maintain the reductant at a desired temperature to maximize its conversion to ammonia and optimize the reduction of NOx in the SCR.

Abstract: Present embodiments relate to a method for synchronizing an electric grid. The method includes receiving a phase voltage of the electric grid. The method further includes determining one or more disturbance frequencies in the phase voltage via a plurality of sequential tracking filters, wherein each of the plurality of tracking filters corresponds to a harmonic of the received phase voltage. The method further includes removing the disturbance frequencies components sequentially to produce a minimally distorted frequency, and performing a PLL operation on the clean frequency to determine a phase angle of the frequency.

Abstract: A system and method for controlling temperature of a urea reductant to form ammonia for NOx reduction in a selective catalytic reducer coupled to a turbocharged engine exhaust by portioning a flow across the reductant between compressed air and ambient air.

Abstract: Embodiments for heating a catalyst are provided. In one example, a method for controlling an internal combustion engine having an exhaust-gas aftertreatment device during a cold-start phase comprises adjusting a temperature of cooling water to a setpoint operating temperature as a function of a degree of aging of the exhaust-gas aftertreatment device of the internal combustion engine, wherein the temperature of the cooling water is increased more quickly as a present degree of aging of the exhaust-gas aftertreatment device increases.

Abstract: Present embodiments relate to a method for synchronizing an electric grid. The method includes receiving a phase voltage of the electric grid. The method further includes determining one or more disturbance frequencies in the phase voltage via a plurality of sequential tracking filters, wherein each of the plurality of tracking filters corresponds to a harmonic of the received phase voltage. The method further includes removing the disturbance frequencies components sequentially to produce a minimally distorted frequency, and performing a PLL operation on the clean frequency to determine a phase angle of the frequency.