Oil pump systems and methods for preventing torque overload in motors of oil pump systems

A system for preventing a torque overload condition of a motor electrically coupled to an inverter, the system comprising:

• a sensing means for sensing an estimated speed value of a rotor of the motor;
• a calculating means for calculating an estimated torque value, based, in part on the estimated speed value of a rotor of the motor, and a dc link voltage value and a dc link current value from the inverter;
• a generating means for generating a maximum available torque value from the estimated speed value and the dc link voltage value;
• a comparing means for comparing the estimated torque value with a maximum available torque value;
• a generating means for generating an error based on the comparison of the estimated torque value and the maximum available torque;
• a converting means for converting the error to a first value;
• a limiting means for limiting the first value between a negative value and zero;
• an adding means for adding the first value to a speed command from the inverter;
• and
• a generating means for generating a final speed command from the speed command from the inverter.

An oil pump system comprising:

• an oil pump;
• a motor in communication with the oil pump;
• an inverter module in electrical communication with the motor, the inverter module configured to generate a speed command;
• and
• a controller module in communication with the inverter module and the motor, the controller module configured to determine an error, based, in part, on an estimated torque value of the motor and a predetermined maximum available torque value, to convert the error into a first value, to limit the first value between a negative value and zero, and to add the first value to the speed command from the inverter to thereby generate a final speed command for the motor.