Azure Dynamics Corp.

Solectria Corporation

Ge Hybrid Technologies, LLC

Beat J Arnet

Kevin Amundsen

John P Deyst

A multiphase current sensing method wherein the sum of the phase currents is zero including: sensing a.c. and/or d.c. currents in first and second phases; sensing a.c. current in a predetermined a.c. frequency range in a third phase; and combining the current sensed in the first and third phases and the second and third phases and determining a gain correction factor to be applied to the currents sensed in the first and second phases.

Method and system for multiphase current sensing

Controlling power switches with a programmable gate controller system proximate associated power switches and remote from the central controller including sensing at least one predetermined condition local to the associated power switches; reporting the sensed conditions to the remote programmable gate controller system; developing, in response to the sensed condition at least one control signal in the remote programmable gate controller system; and applying the control signal to the associated power switches.

Programmable gate controller system and method

Indirect rotor resistance estimation for an AC induction motor is achieved by successively stepping the quadrature command to zero and the direct current command to a predetermined value causing the quadrature stator voltage to decay as a representation of rotor current decay; defining, in response to the decaying stator voltage reaching two spaced thresholds, a voltage/time difference, and retrieving from a storage device the rotor resistance associated with the voltage/time difference.

Indirect rotor resistance estimation system and method

A contactor feedback and pre-charge circuit is disclosed that is capable of i) precharging a load to control the inrush of current, ii) discharging the load to eliminate the risk of shock due to capacitive charge, and iii) shutting the system down in the event the contactor unintentionally opens during operation.

Contactor feedback and precharge/discharge circuit

A voltage source inverter generating a poly phase AC signal is provided that includes an SVPWM controller. The controller is adapted to modify the switching pattern at low sine-wave frequencies creating a more even distribution of the conduction losses. The switching pattern periodically changes the sequence (or rotational sense) of the space vector components from clock-wise to counter-clock-wise direction, and vice-versa.

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Cambridge, MA, United States of America

Beat J Arnet