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US 11,146,205 B2Granted
Method for controlling electric motors, corresponding circuit and computer program product
AssigneeSTMicroelectronics S.r.l.
InventorsAndrea Spampinato, Gianluigi Forte
Life of this patent
Estimating the term…
Abstract
A multi-phase electric motor includes a stator winding. The multi-phase electric motor is controlled by regulating a current flowing in the multi-phase electric motor in response to an applied voltage. An overload condition of the multi-phase electric motor is detected by monitoring a thermal increase of the value of a stator resistance of the stator winding of the multi-phase electric motor during a steady state condition of said multi-phase electric motor in which the current flowing in the motor has constant phase, and the motor is operating at constant load with constant speed.
Claims17
A method of controlling a multi-phase electric motor having a stator winding, comprising:
- regulating a current flowing in the multi-phase electric motor by controlling a multi-phase voltage applied to the multi-phase electric motor through a switch mode inverter driven by a control modulated signal;
- and
- detecting an overload condition of said multi-phase electric motor, by:
- controlling the multi-phase electric motor in a steady state condition in which the current flowing in said multi-phase electric motor has constant phase with the multi-phase electric motor operating at constant load and with a constant speed;
- and
- monitoring a modulation index of the multi-phase voltage applied to the multi-phase electric motor while in the steady state condition to detect a thermal increase of a value of a stator resistance of the stator winding of the multi-phase electric motor, wherein monitoring the modulation index comprises detecting a monotonic increase of the modulation index that occurs while the multi-phase electric motor is in the steady state condition;
- and
- generating an overload detection signal if the monotonic increase is detected.
5 more elements
A The method of controlling a multi-phase electric motor having a stator winding comprising:
- a) regulating a DC current flowing in the multi-phase electric motor by controlling a multi-phase voltage applied to the multi-phase electric motor through a switch mode inverter driven by a control modulated signal to place the motor in a standstill condition;
- b) detecting a steady state condition of the multi-phase electric motor;
- c) monitoring a duty cycle of a voltage applied to a high side of a first leg of the switch mode inverter, while maintaining open high side and low side switches of other legs with the exception of one of the low side switches of said other legs, which is maintained closed in order to detect a thermal increase of a value of a stator resistance of the stator winding of the multi-phase electric motor;
- and
- d) verifying that there is a monotonic increase of the duty cycle while the multi-phase electric motor is in the steady state condition, and if verified then entering into an overload state by generating an overload detection signal.
2 more elements
A device for driving a multi-phase electric motor having a stator winding, comprising:
- a first circuit configured to detect an overload condition of said multi-phase electric motor;
- and
- a second circuit configured to regulate a current flowing in the multi-phase electric motor by controlling a multi-phase voltage applied to the multi-phase electric motor through a switch mode inverter driven by a control modulated signal, the second circuit further configured to control the multi-phase electric motor in a steady state condition in which the current flowing in said multi-phase electric motor has constant phase with the multi-phase electric motor operating at constant load and with a constant speed;
- wherein said first circuit comprises:
- a monitoring circuit configured to monitor a modulation index of the multi-phase voltage applied to the multi-phase electric motor while in the steady state condition to detect a thermal increase of a value of a stator resistance of the stator winding of the multi-phase electric motor, and further configured to generate an overload detection signal in response to verification of a monotonic increase of the modulation index while the multi-phase electric motor is operating in the steady state condition.
2 more elements
A device for driving a multi-phase electric motor having a stator winding, comprising:
- an operation circuit configured to:
- a) regulate a DC current in the multi-phase electric motor while in a standstill condition;
- a steady state detection module configured to:
- b) detect during operation of the multi-phase electric motor a steady state condition of the multi-phase electric motor;
- and
- a circuit configured to detect an overload condition of said multi-phase electric motor by:
- c) monitoring a duty cycle of a voltage applied to a high side of a first leg of a switch mode inverter, while maintaining open high side and low side switches of other legs with the exception of one of the low side switches of said other legs, which is maintained closed in order to detect a thermal increase of a value of a stator resistance of the stator winding of the multi-phase electric motor;
- and
- d) verifying that there is a monotonic increase of the duty cycle while the multi-phase electric motor is in the steady state condition, and in response to verification enter into an overload state and generate an overload detection signal.
6 more elements
Dependencies are inferred from the claim text.