Abstract: A power conversion system may include a plurality of power devices and a sensor operably coupled to at least one of the plurality of power devices and configured to detect a voltage, current, or electromagnetic signature signal associated with the plurality of power devices. The power converter may also include circuitry operably coupled to the plurality of power devices and the sensor. The circuitry may send a respective gate signal to each respective power device of the plurality of power devices, such that each respective gate signal is delayed by a respective compensation delay that is determined for the respective power device based on a respective time delay of the respective power device and a maximum time delay of the plurality of power devices.

Abstract: A power conversion system may include a plurality of power devices and a sensor operably coupled to at least one of the plurality of power devices and configured to detect a voltage, current, or electromagnetic signature signal associated with the plurality of power devices. The power converter may also include circuitry operably coupled to the plurality of power devices and the sensor. The circuitry may send a respective gate signal to each respective power device of the plurality of power devices, such that each respective gate signal is delayed by a respective compensation delay that is determined for the respective power device based on a respective time delay of the respective power device and a maximum time delay of the plurality of power devices.

Abstract: Embodiments of methods and systems of a system for simulating a plant are provided. According to one exemplary embodiment of the invention, there is disclosed a system for simulating a plant. The system may include a controller including plant operation logic for executing control commands to the plant. The system may further include a simulator in communication with the controller, where the simulator may consist of high bandwidth hardware having at least one high bandwidth model of at least a first plant behavior. The simulator may also consist of at least one processor with at least one low bandwidth model of at least a second plant behavior.

Abstract: A gradient amplifier arrangement is described that comprises a gradient amplifier power stage. The device may be employed to provide a current to a gradient coil, as in a MRI system. The circuitry disclosed includes a series coupling of a first bridge amplifier operating at a first voltage, a second bridge amplifier operating at a second voltage, a third bridge amplifier operating at a third voltage, and a gradient amplifier control stage. The amplifiers may provide output voltages at different levels, and may be switched at different times and frequencies to provide a range of output voltage and current levels.

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 high power motor drive converter comprises: a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor; a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage; and a controller for selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by adjusting amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.

Abstract: A high power motor drive converter comprises: a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor; a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage; and a controller for selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by adjusting amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.

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 signal is injected into a neutral point regulator of an inverter drive. The response to that injected signal is monitored as an indication of the capacitance of the inverter drive.

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: A system for preventing objectionable large torque pulsations during the starting and synchronization of a line-start permanent magnet motor compares motor speed with motor synchronous speed and power source phase with the motor back-emf phasor. The motor starting armature is coupled to the power source and the PM armature is disconnected from the power source before motor speed has reached to within a predetermined margin of synchronous speed and before the back-emf phasor has dropped below a predetermined phase difference. After motor speed has approached synchronous speed to within the margin and the phase difference has dropped below the predetermined phase difference, connections are reversed so that the starting armature is disconnected from the power source and the PM armature is coupled to the power source.

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.

Abstract: A set of command signals is generated for application to the respective lines of a four-wire three phase power distribution system to compensate for harmonic distortion and neutral unbalance. A transform operation is performed upon a first set of signals, which collectively represent the uncompensated load current in each of the main transmission lines of the power distribution system, to generate a second set of signals which collectively represent the active and reactive components of the current in the system. Signal components at the fundamental frequency of the three phase system are removed from the active and reactive components to provide only harmonic active and reactive components. A reverse transform operation is performed upon the harmonic components to provide a set of command signals.