In-vehicle motor-driven compressor and method for controlling in-vehicle motor-driven compressor
AssigneeKabushiki Kaisha Toyota Jidoshokki
InventorsTakashi Kawashima, Kazuki Najima
Life of this patent
Estimating the term…
Abstract
An in-vehicle motor-driven compressor includes a temperature rise estimator configured to estimate a temperature rise of the diode based on an expected reverse current, an on-voltage of the diode, and a heat resistance of the diode. The in-vehicle motor-driven compressor further includes a rotation speed controller configured to set a rotation speed limit of the electric motor, based on the estimated temperature rise of the diode so that a temperature of the diode does not exceed a junction temperature of the diode even when the electric motor is stopped and the reverse current flows through the diode, and limit a rotation speed of the electric motor to lower than or equal to the rotation speed limit.
Claims4
An in-vehicle motor-driven compressor, comprising:
- a compression unit configured to compress a fluid;
- an electric motor configured to drive the compression unit;
- and
- an inverter configured to drive the electric motor, wherein
- the inverter includes a switching element that is configured to perform switching and convert DC voltage of a battery into AC voltage to drive the electric motor and a diode that is connected in parallel to the switching element, and
- the in-vehicle motor-driven compressor further includes
- a temperature rise estimator configured to estimate a temperature rise of the diode based on an expected reverse current, an on-voltage of the diode, and a heat resistance of the diode, wherein the reverse current is a current that flows from the electric motor via the diode to the battery when the electric motor is stopped and a back electromotive voltage of the electric motor exceeds an input voltage of the battery, and
- a rotation speed controller configured to set a rotation speed limit of the electric motor, based on the estimated temperature rise of the diode so that a temperature of the diode does not exceed a junction temperature of the diode even when the electric motor is stopped and the reverse current flows through the diode, and limit a rotation speed of the electric motor to lower than or equal to the rotation speed limit.
A method for controlling an in-vehicle motor-driven compressor, wherein the in-vehicle motor-driven compressor includes a compression unit configured to compress a fluid, an electric motor configured to drive the compression unit, and an inverter configured to drive the electric motor, wherein the inverter includes a switching element that is configured to perform switching and convert DC voltage of a battery into AC voltage to drive the electric motor and a diode that is connected in parallel to the switching element, the method comprising:
- estimating a temperature rise of the diode based on an expected reverse current, an on-voltage of the diode, and a heat resistance of the diode, wherein the reverse current is a current that flows from the electric motor via the diode to the battery when the electric motor is stopped and a back electromotive voltage of the electric motor exceeds an input voltage of the battery;
- setting a rotation speed limit of the electric motor based on the estimated temperature rise of the diode so that a temperature of the diode does not exceed a junction temperature of the diode even when the electric motor is stopped and the reverse current flows through the diode;
- and
- limiting a rotation speed of the electric motor to lower than or equal to the rotation speed limit.
An in-vehicle motor-driven compressor, comprising:
- a compression unit configured to compress a fluid;
- an electric motor configured to drive the compression unit;
- and
- an inverter configured to drive the electric motor, wherein
- the inverter includes a switching element that is configured to perform switching and convert DC voltage of a battery into AC voltage to drive the electric motor and a diode that is connected in parallel to the switching element, and
- the in-vehicle motor-driven compressor includes circuitry configured to estimate a temperature rise of the diode based on an expected reverse current, an on-voltage of the diode, and a heat resistance of the diode, wherein
- the reverse current is a current that flows from the electric motor via the diode to the battery when the electric motor is stopped and a back electromotive voltage of the electric motor exceeds an input voltage of the battery, and
- the circuitry is configured to set a rotation speed limit of the electric motor, based on the estimated temperature rise of the diode so that a temperature of the diode does not exceed a junction temperature of the diode even when the electric motor is stopped and the reverse current flows through the diode, and limit a rotation speed of the electric motor to lower than or equal to the rotation speed limit.
Dependencies are inferred from the claim text.