Abstract: A double fed induction generator (DFIG) converter method are presented in which rotor side current spikes are attenuated using series-connected damping resistance in response to grid fault occurrences or grid fault clearances.

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 method for adapting a kinetic model of a SCR is described. In one example, the kinetic model is adapted for stored ammonia, ammonia release rate, and ammonia storage capacity. The method may be useful for adjusting engine control parameters for the purpose of reducing engine emissions.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. The inputs to the QTF may be either single input, multiple outputs, or alternatively, multiple inputs, multiple outputs. Furthermore, the second state of either of the two QTF transformations may be either positive or negative. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications. A frequency estimator estimates the grid frequency of the electric grid and outputs the estimated frequency to the QTF algorithms. The frequency estimator may include a three-phase phase-locked-loop (three-phase PLL) suitable for estimating the center frequencies of multiple phases of the electric grid. The frequency estimator may also include means for reducing the harmonics in the grid system.

Abstract: Integrated AC regenerative motor drives and operating methods are presented in which a precharging circuit is provided with an IGBT, a diode and a parallel current limiting component in an intermediate DC circuit between a switching rectifier and an output inverter, and the drive is operated in one of three modes for motoring, regenerating and precharging.

Abstract: Embodiments for injecting reducing agents are provided. In one example, an injection device for feeding reducing agents into an exhaust-gas purification system of an internal combustion engine for reduction of nitrogen oxide emissions comprises an injector, and an evaporation device for evaporating first and second reducing agents, the injection device connected to in each case one storage vessel for the first reducing agent and a storage vessel for the second reducing agent, the first and second reducing agents liquid at room temperature.

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: Electrical power quality test circuitry for testing response of an electrical device to input power disturbances is provided. The test circuitry includes a power structure having a rectifier configured to convert incoming AC voltage to DC voltage on a DC bus, and a power inverter configured to convert DC voltage from the bus to three-phase output AC voltage applied to the electrical device. The test circuitry also includes a control circuit configured to apply control signals to at least the power inverter to emulate at least one of a change in the amplitude of at least one phase of the output AC voltage at least one phase angle of at least one phase of the output AC voltage, and a frequency change for all phases of the output AC voltage.

Abstract: An engine and related control system determine an amount of fuel diluting the engine oil in the oil pan. Such information can be used to recommend an oil change and to estimate a fraction of biodiesel in the fuel supplied to the engine. According to one embodiment, actual oil volume in the oil pan is based on a signal from a level sensor in the oil and a theoretical oil volume is determined based on initial oil volume and fuel entering the oil in the oil pan, fuel leaving the oil pan due to evaporation, and oil being consumed in the combustion chamber. Based on the difference between the actual and theoretical oil volumes, a proportion of heavy fuel components or biodiesel can be determined and transmitted to an engine control system.

Abstract: Systems and methods for estimating an efficiency of a catalyst placed in an exhaust path of a combustion engine are disclosed. In one example approach, a method comprises: ageing the catalyst consecutively at different temperatures for definite time periods; measuring the catalyst conversion efficiency after each ageing step; calculating the ageing factor for each step of the ageing procedure and the accumulative value of the ageing factors for all steps of the ageing procedure; estimating catalyst efficiency correlation factors related to the measured catalyst conversion efficiency for each temperature point and for all ageing conditions; determining a correlation between the catalyst efficiency correlation factors and the accumulative value of the ageing factors; and calculating the conversion efficiency of the aged catalyst based on a predetermined correlation between the accumulative ageing factor and the catalyst efficiency correlation factor.

Abstract: Embodiments for determining NH3 slip past a catalyst are provided. In one example, a filtering method for a NOx sensor of an exhaust gas system having an SCR catalytic converter comprises determining NOx concentration upstream of the catalytic converter, measuring NOx concentration downstream of the catalytic converter, modeling NOx conversion, modeling NH3 slip behavior, calculating a NOx error of the NOx modeling, calculating an NH3 error of the NH3 modeling, assigning data of the NOx sensor as NH3 measured values when a ratio of the NOx error to the NH3 error is greater than an upper threshold value, and assigning data of the NOx sensor as NOx measured values when the ratio of the NOx error to the NH3 error is smaller than a lower threshold value. In this way, NOx slip and NH3 slip may be determined from a common sensor.

Abstract: A particulate filter for a vehicle exhaust system includes a primary filter surrounded by a secondary filter and a quenching agent injection nozzle arranged upstream of the primary filter. In a normal mode, exhaust flows through the primary filter, and in a fail-safe mode or a mixed mode, at least some exhaust flows through the secondary filter and quenching agent is injected via the nozzle to cool the primary filter. The fail-safe or mixed modes may be enacted during an overload of the primary filter, for example. If engine shutdown is initiated during regeneration of the primary filter, a rate of quenching agent injection may be adjusted so that the regeneration may be completed at a safe temperature.

Abstract: A method and an engine are disclosed for determining an amount of fuel in the engine oil. Such information can be used to recommend an oil change and to estimate a fraction of biodiesel in the fuel supplied to the engine. According to one embodiment, actual oil volume in the oil pan is based on a signal from a level sensor in the oil and a theoretical oil volume is determined based on initial oil volume and fuel entering the oil in the oil pan, fuel leaving the oil pan due to evaporation, and oil being consumed in the combustion chamber. Based on the difference between the actual and theoretical oil volumes, a proportion of biodiesel can be determined and transmitted to an engine control system.

Abstract: A double fed induction generator (DFIG) system and controller are presented in which the rotor side converter is preloaded with one or more initial values for resuming regulated operation to counteract transients upon deactivation of the crowbar protection circuit to provide grid fault ride through.

Abstract: Embodiments of a particle sensor are provided. In one example, a particle sensor for an exhaust system comprises at least two inlet openings for an exhaust-gas flow of the exhaust system, wherein the inlet openings are of different sizes, and at least two sensor elements, wherein in each case one sensor element is arranged downstream of one inlet opening. In this way, the relative proportion of different-sized particles within the exhaust-gas flow may be determined.

Abstract: A method for monitoring a regulated emissions concentration C, in the exhaust gas of an internal combustion engine is provided. The method comprises directing the exhaust gas through an exhaust-gas turbocharger, directing at least a portion of the exhaust gas through an exhaust-gas recirculation system, measuring an air ratio ?meas in the exhaust gas with a lambda probe, measuring a rotational speed nT of the exhaust-gas turbocharger with a sensor, and determining the regulated emission concentration Ci based on the air ratio ?meas and the rotational speed nT. In this way, the emission concentration of the exhaust may be determined as a function of the rotational speed of the turbine.

Abstract: A method for adapting a kinetic model of a SCR is described. In one example, the kinetic model is adapted for stored ammonia, ammonia release rate, and ammonia storage capacity. The method may be useful for adjusting engine control parameters for the purpose of reducing engine emissions.

Abstract: A system and method for determining ammonia deposition and controlling an engine is described. In one example, an amount of ammonia deposited in an engine exhaust is determined and the deposited ammonia is purged after the amount of ammonia deposited reaches a threshold level. The method may decrease ammonia use and ammonia emissions from a vehicle.

Abstract: A system and method for controlling an engine is described. In one example, an actuator is adjusted to reduce the possibility of degradation of an engine component. The method may provide increase engine component operational life so as to improve engine emissions during the life cycle of the engine.