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

Patent metadata

Field	Value
Publication number	US-12556115-B2
Application number	US-202018007691-A
Country	US
Kind code	B2
Filing date	Jun 3, 2020
Priority date	Jun 3, 2020
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a first electrical current output setpoint, identifying a first operational condition based on the first electrical current output setpoint, providing, based on the identified first operational condition, a first pulse width modulated (PWM) signal having a first predetermined duty cycle, based on the first electrical current output setpoint, provided on a predetermined period, receiving a second electrical current output setpoint, identifying a second operational condition different from the first operational condition based on the second electrical current output setpoint, and providing, based on the identified second operational condition, a second PWM signal having a second predetermined duty cycle, based on the second electrical current output setpoint, provided on a predetermined multiple of the predetermined period.

First claim

What is claimed is:

1 . A computer-implemented method for electric current control, 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.

2 . The computer-implemented method of claim 1 , wherein providing the first PWM signal comprises:
determining a start of a PWM cycle having a first duration of time based on the predetermined period; providing an electrical signal; halting the electrical signal based on determining that the electrical signal has been provided for a second duration of time, based on the first predetermined duty cycle, has elapsed; and determining an end of the PWM cycle based on determining that the first duration of time has elapsed.

3 . The computer-implemented method of claim 1 , wherein providing the second PWM signal comprises:
determining a start of a first PWM cycle having a first duration of time based on the predetermined period; providing an electrical signal; halting the electrical signal based on determining that a second duration of time, based on the second predetermined duty cycle, has elapsed; determining an end of the first PWM cycle based on determining that the first duration of time has elapsed; determining the start of a predetermined number, based on the predetermined multiple, of second PWM cycles having the first duration of time based on the predetermined period; halting the electrical signal during the second PWM cycles; and determining the end of the predetermined number of second PWM cycles have occurred.

4 . The computer-implemented method of claim 3 , further comprising determining the predetermined multiple based on the second operational condition.

5 . The computer-implemented method of claim 1 , wherein providing the second PWM signal comprises:
determining a start of a PWM cycle having a second duration of time based on the predetermined period and the predetermined multiple; providing an electrical signal; halting the electrical signal based on determining that a second duration of time, based on the second predetermined duty cycle, has elapsed; and determining an end of the PWM cycle based on determining that the second duration of time has elapsed.

6 . The computer-implemented method of claim 1 , wherein providing the second PWM signal comprises:
generating a PWM pulse at a frequency based on the predetermined period; transmitting an electrical pulse based on the generated PWM pulse; and ignoring a predetermined number of PWM pulses based on the predetermined multiple.

7 . The computer-implemented method of claim 1 , wherein identifying the first operational condition is based on:
determining a target duty cycle based on the first electrical current output setpoint; determining that the target duty cycle is equal to or longer than a predetermined threshold duty cycle; and providing the target duty cycle as the first predetermined duty cycle.

8 . The computer-implemented method of claim 1 , wherein identifying the second operational condition is based on:
determining a target duty cycle based on the second electrical current output setpoint; determining that the target duty cycle is shorter than a predetermined threshold duty cycle; and determining the second predetermined duty cycle based on the target duty cycle.

9 . The computer-implemented method of claim 1 , wherein providing the second PWM signal comprises skipping a transmission of a predetermined number of PWM pulses before transmitting a next PWM pulse.

10 . The computer-implemented method of claim 1 , wherein the controller comprises an operational condition identification module, a threshold module, a normal signal generator module, and a modified signal generator module, wherein providing the first PWM signal comprises providing the first PWM signal by the normal signal generator module, and wherein providing the second PWM signal comprises providing the second PWM signal by the modified signal generator module.

11 . The computer-implemented method of claim 10 , wherein the threshold module is connected with the operational condition identification module, the normal signal generator module, and the modified signal generator module, and wherein identifying the second operational condition comprises determining, by the threshold module, that the at least one PWM signal is equal to or less than the at least one of the minimum turn-on time or the minimum turn-off time of the electrical circuit, and wherein providing the second PWM signal comprises engaging the modified signal generator module to provide the second PWM signal, and the engaging comprises engaging the modified signal generator module as a function of determining that at least one PWM signal transmitted by the controller is equal to or less than the at least one of the minimum turn-on time or the minimum turn-off time of the electrical circuit.

12 . 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 con

Assignees

• Woodward Inc

Inventors

• Jayaraman Ganga P
• Micic Dragan

Classifications

• H02P6/28

  Arrangements for controlling current (H02P6/10 takes precedence) · CPC title

• H02M1/0038

  Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control · CPC title

• H02M1/0012

  Control circuits using digital or numerical techniques (in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873) · CPC title

• H02M1/15

  using active elements · CPC title

• H02P2209/095

  One pulse per half period · CPC title