Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.

Abstract: A circuit for balancing a sub-stack voltage in a stack of ultracapacitors includes a pair of electrical leads that are connectable across a first sub-stack of one or more ultracapacitors, wherein a stack includes N sub-stacks of ultracapacitors coupled to an electrical bus, a discharge device switchably connectable with the pair of electrical leads, the discharge device configured to discharge the sub-stack of ultracapacitors, a voltage sensing circuit coupled to the electrical bus and configured to sense and output a voltage of the stack of ultracapacitors after the first sub-stack of one or more ultracapacitors has been discharged to a given threshold, and a voltage amplifier coupled to the output of the voltage sensing circuit and coupled to the pair of electrical leads, the voltage amplifier configured to provide a re-charge voltage to the first sub-stack of one or more ultracapacitors.

Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.

Abstract: A circuit for balancing a sub-stack voltage in a stack of ultracapacitors includes a pair of electrical leads that are connectable across a first sub-stack of one or more ultracapacitors, wherein a stack includes N sub-stacks of ultracapacitors coupled to an electrical bus, a discharge device switchably connectable with the pair of electrical leads, the discharge device configured to discharge the sub-stack of ultracapacitors, a voltage sensing circuit coupled to the electrical bus and configured to sense and output a voltage of the stack of ultracapacitors after the first sub-stack of one or more ultracapacitors has been discharged to a given threshold, and a voltage amplifier coupled to the output of the voltage sensing circuit and coupled to the pair of electrical leads, the voltage amplifier configured to provide a re-charge voltage to the first sub-stack of one or more ultracapacitors.

Abstract: An apparatus for repeatably generating electrical arcs for testing an electrical switching device, such as an arc fault circuit interrupter, includes a stationary electrode and a movable electrode that is moved along a path of travel by an electromechanical device under the control of a controller that receives data from either a current measuring device or a voltage measuring device to detect the initiation of an arc. The movable electrode is caused to first make physical contact with the stationary electrode, and then is moved away from the stationary electrode until an arc is detected. Additionally, the movable electrode may be moved towards and away from the stationary electrode according to a test profile to control the magnitude of the randomness of the arc.

Abstract: An apparatus for repeatably generating electrical arcs for testing an electrical switching device, such as an arc fault circuit interrupter, includes a stationary electrode and a movable electrode that is moved along a path of travel by an electromechanical device under the control of a controller that receives data from either a current measuring device or a voltage measuring device to detect the initiation of an arc. The movable electrode is caused to first make physical contact with the stationary electrode, and then is moved away from the stationary electrode until an arc is detected. Additionally, the movable electrode may be moved towards and away from the stationary electrode according to a test profile to control the magnitude of the randomness of the arc.

Abstract: An on-line monitor for electrical faults in the stator of an ac motor has a single di/dt current transformer or three separate di/dt current transformers coupled to the three phase conductors of the ac supply. The windings of the transformer, or transformers, are selected to generate a single sensed signal containing a linear combination of components of current in the three phase conductors weighted relatively so that algebraic differences between components from any two phase conductors is non-zero, such as preferably 2A+B-C or 3A+2B+C. The single sensed current signal is bandpass filtered to generate a pulse signal which is applied to an analyzer. The analyzer, preferably implemented by a microcontroller, generates an output based upon a combination of the amplitude and frequency of occurrence of the current pulse signal including a time attenuated accumulation of the pulses.

Abstract: Arc faults are detected by bandpass filtering the current to generate a sensed current signal with a pulse each time an arc is struck. A resettable integrator integrates this sensed current repetitively over equal time intervals such as each cycle of the ac current. The integrated value of the sensed current is compared with the value for the previous corresponding time interval stored in a sample and hold circuit, with the indications of interval to interval increases and decreases in the integrated sensed values for a selected number, such as six, of the most recent time intervals stored in a shift register. For each time interval, a chaos detector counts the number of changes between increases and decreases for the selected number of most recent corresponding time intervals and accumulates a weighted sum of the counts which is time attenuated. When the sum reaches a predetermined amount, an output such as a trip signal for a circuit breaker is generated.