Modulation techniques for improved inverter and electric motor operation

A controller, comprising:

• electronic circuitry configured to:
• receive voltage reference signals and phase current signals associated with operation of a motor during at least one of stall conditions or low-speed conditions;
• and
• generate reference modulation signals;
• a common mode signal generator configured to:
• determine maximum and minimum voltage values among the voltage reference signals;
• identify corresponding phase currents for phases having the maximum and minimum voltage values;
• compare absolute values of the identified phase currents;
• and
• generate a common mode signal based on a clamp value and comparing the absolute values;
• a clamp control module configured to:
• modify the reference modulation signals by adding the common mode signal to produce clamped modulation signals;
• and
• a pulse width modulation module configured to:
• compare the clamped modulation signals with carrier signals to generate pulse width modulation gate pulses for controlling switching devices of an inverter to supply power to the motor.

A work machine comprising:

• an electric motor configured to operate in stall conditions and low speed conditions;
• an inverter comprising switching devices and diodes configured to supply power to the electric motor;
• and
• a controller configured to:
• receive voltage reference signals and phase current signals associated with operation of the electric motor;
• generate a common mode signal based on comparing absolute values of the phase current signals corresponding to maximum and minimum values among the voltage reference signals;
• modify reference modulation signals by adding the common mode signal to produce clamped modulation signals;
• and
• control the switching devices using pulse width modulation gate pulses generated by comparing the clamped modulation signals with carrier signals.