System and method for controlling operation of a motor

A motor controller (100) for operating an electric motor (102) comprising a rotor (104), and one or more coil windings (106, 108, and 110), the motor controller (100) comprising:

• one or more position sensors (116) that identify a particular sector (302A) from a plurality of sectors (302A-F) in the electric motor (102) in which the rotor (104) is positioned;
• a power source (126) that supplies direct current for rotating the rotor (104);
• an inverter (124) operatively coupled to the power source (126) and that converts direct current supplied by the power source (126) into alternating current, wherein the inverter (124) comprises a plurality of switches (502A-F) that regulate the alternating current supplied to the coil windings (106, 108, and 110);
• one or more current sensors (122) coupled to the electric motor (102) and that measure the alternating currents supplied to the coil windings (106, 108, and 112) when the rotor (104) is positioned in the particular sector (302A);
• a single speed controller (120) operatively coupled to the position sensors (116) and that determines a reference quadrature-axis current of the rotor (104) when the rotor (104) is positioned in the particular sector (302A) using a target speed and a current speed of the electric motor (102), wherein the current speed is determined based on the rotor (104) position information obtained using the position sensors (116), wherein the target speed is received from a speed input system (112);
• one or more current transformation units (128 and 130) operatively coupled to the current sensors (122) and that determine an actual quadrature-axis current of the rotor (104) based on the measured alternating currents;
• a single current controller (132) operatively coupled to the current transformation units (128 and 130) and the single speed controller (120), wherein the current controller (132) determines a duty cycle of a set of pulse width modulation (PWM) gate signals used for controlling the current speed at which the rotor (104) rotates within the particular sector (302A) based on the reference quadrature-axis current and the actual quadrature-axis current;
• and
• a PWM signal generator (134) operatively coupled to the single current controller (132) and the inverter (124), wherein the PWM signal generator (134):
• generates the PWM gate signals having the determined duty cycle, and
• modulates operations of a specific pair of switches (502C and 502E) in the inverter (124) using the generated PWM gate signals to incrementally vary the current speed of the rotor (104) when moving from the particular sector to another sector in the plurality of sectors (302A-F) to achieve the target speed, such that a variation in a torque output generated due to movement of the rotor (104) from the particular sector to the another sector of electric motor (102) is within a designated range.