Power tool dynamic motor field weakening system and method
AssigneeMilwaukee Electric Tool Corporation
InventorAlex R. Kuhls
Life of this patent
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Abstract
Embodiments of the disclosure provide a system and method of operating a motor control algorithm in a power tool to utilize dynamic field weakening. The method includes operating the motor according to dynamic field weakening, measuring sensor readings, and sampling the sensor readings. The method also includes calculating an averaged sensor reading value, comparing the averaged sensor reading value to a predetermined sensor value, and continuing to operate according to dynamic field weakening if the averaged sensor reading has not exceeded the predetermined sensor value. The method further includes changing the motor control algorithm to a static motor commutation sequence if the averaged sensor reading has exceeded the predetermined sensor value.
Claims19
A method of changing a motor control algorithm in a power tool, the power tool including a motor, a stator, and a sensor, the method comprising:
- operating, via a controller connected to the motor, the motor according to dynamic field weakening by operating the motor above a rated speed by weakening a magnetic field of the stator;
- measuring pressure sensor readings using a pressure sensor;
- sampling the pressure sensor readings using the pressure sensor while the motor is running to generate pressure sensor reading samples;
- calculating, via the controller, an averaged pressure sensor reading value by averaging the pressure sensor reading samples;
- comparing, via the controller, the averaged pressure sensor reading value to a predetermined pressure sensor value;
- continuing to operate the motor according to the dynamic field weakening if the averaged pressure sensor reading has not exceeded the predetermined pressure sensor value;
- and
- changing the motor control algorithm to a static motor commutation sequence if the averaged sensor reading has exceeded the predetermined sensor value.
A hydraulic power tool comprising:
- a motor with a stator;
- a pump;
- a fluid distribution network in fluid communication with the pump;
- a pressure sensor in communication with the fluid distribution network;
- and
- a controller connected to the motor and the pressure sensor;
- the controller operating the motor according to dynamic field weakening by operating the motor above a rated speed by weakening a magnetic field of the stator;
- the controller measuring pressure sensor readings;
- the controller sampling the pressure sensor readings while the motor is running to generate pressure sensor reading samples;
- the controller calculating an averaged pressure sensor reading value by averaging the pressure sensor reading samples;
- the controller comparing the averaged pressure sensor reading value to a predetermined pressure sensor value;
- and
- the controller continuing to operate according to dynamic field weakening if the averaged pressure sensor reading value has not exceeded the predetermined pressure sensor value;
- and
- the controller changing a motor control algorithm to a static motor commutation sequence if the averaged pressure sensor reading has exceeded the predetermined pressure sensor value.
Dependencies are inferred from the claim text.