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US 12,763,709 B2Granted
Sensorless observer based zero-speed start for fuel cell compressor
AssigneeGarrett Transportation I Inc.
InventorsAbhijit Sahu, Najib Rouhana, Ali Najmabadi
Life of this patent
Estimating the term…
Abstract
Estimation of motor rotor position including measuring a voltage drop in an inverter during an initialization of an electric motor at zero revolutions per minute and estimating a rotational speed and position of the electric motor in response to a counter-electromotive force and the voltage drop during an increasing of the rotational speed of the electric motor from zero revolutions per second to a steady state rotational speed.
Claims18
An apparatus comprising:
- an electric motor;
- an inverter for converting a direct current to a three phase alternating current for driving the electric motor;
- a motor controller for determining a voltage drop across the inverter while maintaining a rotational speed of the electric motor at zero revolutions per second, for estimating a rotational position of the electric motor in response to the voltage drop and a flux based observer while increasing the rotational speed of the electric motor from zero revolutions per minute to a commanded rotational speed, and controlling a switching of the inverter in response to the rotational position;
- a memory for storing a data indicative of a magnitude of the voltage drop, and
- wherein the motor controller is configured to determine that the voltage drop results from a first switching loss of a first transistor within the inverter, a second switching loss of a second transistor within the inverter, and a dead time between switching of the first transistor and the second transistor.
2 more elements
A method comprising:
- measuring a voltage drop in an inverter during an initialization of an electric motor;
- estimating a rotational speed and position of the electric motor in response to a counter-electromotive force and the voltage drop during an increasing of the rotational speed of the electric motor from zero revolutions per second to a steady state rotational speed;
- and
- wherein the voltage drop results from a first switching loss of a first transistor, a second switching loss of a second transistor within the inverter and a dead time between the switch of the first transistor and switching of the second transistor.
1 more element
A system for compressing a fluid comprising;
- a centrifugal compressor for receiving the fluid via an intake, for increasing a pressure of the fluid using an impeller to generate a compressed fluid, and for outputting the compressed fluid to a fuel cell;
- an electric motor for driving the impeller within the centrifugal compressor in response to a three phase alternating current;
- an inverter for generating the three phase alternating current in response to a switching control signal and a direct current;
- a motor controller for generating the switching control signal, for measuring a voltage drop in the inverter while maintaining the rotational speed of the electric motor at zero revolutions per second, and for estimating the rotational speed and a position of the electric motor in response to a counter-electromotive force and the voltage drop during an increasing of the rotational speed of the electric motor from zero revolutions per second to a steady state rotational speed, and
- wherein the voltage drop results from a first switching loss of a first transistor within the inverter, a second switching loss of a second transistor within the inverter and a dead time between the switching of the first transistor and the switching of the second transistor.
2 more elements
Dependencies are inferred from the claim text.