Reduction of current ripple due to MOSFET switching delays in PWM-based drives

A control system comprising:

• an input configured to receive electrical current setpoints;
• a monitor circuit configured to identify at least a first operational condition and a second operational condition based on received electrical current setpoints;
• a pulse generator configured to generate an electrical pulse width modulated (PWM) signal comprising a plurality of PWM pulses based on received electrical current setpoints and provide the PWM signal on a predetermined period;
• a pulse inhibitor configured to modify the PWM signal by passing the PWM pulses to an electrical load based on the first operational condition, and by blocking selected PWM pulses of the PWM signal and passing non-selected PWM pulses to the electrical load based on the second operational condition, wherein the non-selected PWM pulses are provided to the electrical load on a predetermined multiple of the predetermined period;
• and
• a transmitter configured to transmit the modified PWM signal to the electrical load,
• wherein the monitor circuit is configured to identify the second operational condition based on at least one of a minimum turn-on time of an electrical circuit configured to transmit the PWM signal, and a minimum turn-off time of the electrical circuit, and wherein identifying the second operational condition comprises determining that at least one PWM signal transmitted by the controller is equal to or less than at least one of the minimum turn-on time or the minimum turn-off time of the electrical circuit.

A non-transitory computer storage medium encoded with a computer program, the computer program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising:

• receiving, by a controller configured to output pulse width modulation (PWM) signals, a first electrical current output setpoint;
• identifying, by the controller, a first operational condition based on the first electrical current output setpoint;
• providing, by the controller to an electrical load and based on the identified first operational condition, a first PWM signal having a first predetermined duty cycle, based on the first electrical current output setpoint, provided on a predetermined period;
• receiving, by the controller, a second electrical current output setpoint;
• identifying, by the controller, a second operational condition different from the first operational condition based on the second electrical current output setpoint, wherein identifying the second operational condition is based on at least one of a minimum turn-on time of an electrical circuit configured to transmit the PWM signal, and a minimum turn-off time of the electrical circuit, and wherein identifying the second operational condition comprises determining that at least one PWM signal transmitted by the controller is equal to or less than at least one of the minimum turn-on time or the minimum turn-off time of the electrical circuit;
• and
• providing, by the controller to the electrical load and based on the identified second operational condition, a second PWM signal having a second predetermined duty cycle different from the first predetermined duty cycle, based on the second electrical current output setpoint, provided on a predetermined multiple of the predetermined period.