Abstract: A technique is provided for imaging a field of view using an X-ray source comprising two or more emission points. The two or more emission points may be independently operated. Independent operation of the two or more emission points in performed in accordance with a list of commands that specifies the operation of the emission points. The list of commands, in one embodiment, is stored in a sequence buffer. In other embodiments, the list of commands is generated for a given usage, without being stored in a sequence buffer.

Abstract: A technique is provided for imaging a field of view using an X-ray source comprising two or more emission points. The two or more emission points may be independently operated. Independent operation of the two or more emission points in performed in accordance with a list of commands that specifies the operation of the emission points. The list of commands, in one embodiment, is stored in a sequence buffer. In other embodiments, the list of commands is generated for a given usage, without being stored in a sequence buffer.

Abstract: An apparatus for anti-islanding protection of a distributed generation with respect to a feeder connected to an electrical grid is disclosed. The apparatus includes a sensor adapted to generate a voltage signal representative of an output voltage and/or a current signal representative of an output current at the distributed generation, and a controller responsive to the signals from the sensor. The controller is productive of a control signal directed to the distributed generation to drive an operating characteristic of the distributed generation out of a nominal range in response to the electrical grid being disconnected from the feeder.

Abstract: A method and system for compensating for line imbalances in line commutated converters. The controller includes a phase-locked loop (PLL) synchronizing tool which receives the line to line voltage signals and generates firing angle and frequency signals used for synchronizing the two input signals. The PLL controller, in addition to the firing angle and frequency signals, also generates signals representative of filtered values of amplitudes for each of the line to line voltage signals. A voltage imbalance compensation processor associated with the bridge firing controller receives the filtered amplitude signals and also a signal representative of the firing sector of the bridge. The voltage imbalance compensation processor generates, based upon the sector signal and the received filtered amplitude signals a amplitude signal used by a current regulator which is compensated for line imbalances present in the line voltage.

Abstract: A method and system for determining zero current level occurrences in a reversible power converter without requiring additional component complexity and costs. A digital controller selectively determines the line to line voltage for the most recently fired thyristor pair. The selected line to line voltage is identified as the bridge reconstruction voltage and is compared against the actual bridge output voltage for the conducting bridge. The difference between the two voltage signals is identified as the bridge error voltage and the sign of its magnitude is indicative of a load current zero level occurrence. A zero current level occurrence happens whenever the bridge error voltage drops below zero. This indication is positive and substantially instantaneous and safely enables the reversal of power flow without the risk of line faults due to cross-bridge short circuits.

Abstract: A method and system for compensating for voltage notches in phase locked loop (PLL) control devices. A bridge firing controller receives signals representative of two of the line to line voltages received by the bridge. The controller includes a PLL synchronizing tool which receives the line to line voltage signals and generates a synchronizing phase error signal for aligning the phases of the two input signals. The controller, for a predetermined period following bridge firing, determines whether a voltage notch has occurred. If so, the controller substitutes model control signals for actual control signals so as to reduce the effect of the notch on the generated phase error signal used for synchronization. If not, the controller continues to use the actual control signals to generate the phase error signal. Once the predetermined period has expired, the controller utilizes the actual control signals to generate the phase error signal.

Abstract: An active damping control device for an active power filter includes a filter circuit having an inductor and a capacitor for suppressing noise in the active power filter; a first current sensor for sensing a three phase capacitor current of the filter capacitor; a second current sensor for detecting a three phase load current; and an active power filter controller for extracting the fundamentals of the capacitor and load currents and calculating a reference current for the active power filter.