US 2023/0266743 A1 · AUTOMATIC TUNING OF A PROPORTIONAL-INTEGRAL-DERIVATIVE CONTROLLER FOR DC-DC BUCK SWITCHING POWER CONVERTER

Abstract

A method of automatically tuning a proportional-integral-derivative (PID) controller (102) controlling a DC-DC converter (100) includes substituting the PID controller (102) with a modified relay feedback test (MRFT) (104) controller having a threshold parameter (β) and a magnitude parameter (h), iteratively determining a current error signal (e [k]) by measuring an output voltage (Vo[k]) of the DC-DC converter (100) and comparing it to a desired reference output voltage (Vo-ref), input the error signal (e[k]) to the MRFT (104), determining an output value (u[k]) of the MRFT, update the duty cycle (D) based on the output value (u[k]), operating the DC-DC converter (100) using the updated duty cycle (D), exciting oscillations in the loop containing the MRFT (104) and the DC-DC converter (100), measuring a frequency (Ω0) and amplitude (α0) of the output voltage (Vo[k]), updating PID controller parameters based on the frequency (Ω0) and amplitude (α0), and substituting the MRFT (104) with the PID controller (102).

Claims18

Dependent claims

A method of automatically tuning a proportional-integral-derivative (PID) controller controlling a DC-DC buck switching power converter, comprising:

a) substituting the PID controller with a modified relay feedback test (MRFT) block having an MRFT magnitude (h) and a threshold parameter (β);
b) determining a current error signal (e[k])by measuring an output voltage (Vo[k]) of the DC-DC buck switching power converter and comparing the output voltage (vo) to a desired reference output voltage (Vo-ref);
c) inputting the error signal (e[k]) to the MRFT block;
d) producing a MRFT block output signal u[k] in accordance with the MRFT block equations, which can only be D+h or D−h;
e) operating the DC-DC buck switching power converter using the updated nominal duty cycle (D);
f) repeating steps from b) through e), which results in generation of self-excited oscillations due to the switching of the MRFT block output between the values D+h and D−h, until a predefined number of cycles (Ncycles) is observed;
g) measuring a frequency (Ω0) and amplitude (a0) of oscillations of the output voltage (Vo[k]) of the DC-DC buck switching power converter;
h) updating PID controller parameters based on the frequency (Ω0) and amplitude (a0) of the oscillations of the voltage output (Vo[k]) of the DC-DC buck switching power converter;
and
i) substituting the MRFT block with the PID controller.

7 more elements

A non-transitory computer readable storage medium having data stored therein representing software executable by a computer, the software including instructions to:

switch a controller circuit of a DC-DC buck switching power converter from a proportional-integral-derivative (PID) controller enforcing a nominal duty cycle (D) of the converter to a modified relay feedback test (MRFT) block having an MRFT magnitude (h) and a threshold parameter (β);
determine a current error signal (e[k]) by measuring an output voltage (Vo[k]) of the DC-DC buck switching power converter and comparing the output voltage (Vo[k]) to a desired reference output voltage (Vo-ref);
input the error signal (e[k]) to the MRFT block;
determine a controller output signal (u[k]) of the MRFT block;
update the nominal duty cycle (D) to the value given by the controller output signal (u[k]);
operate the DC-DC buck switching power converter using the updated nominal duty cycle (D);
observe appearance of self-excited oscillations and repeat the preceding instructions for a predetermined number of cycles (Ncycles) of these oscillations;
measure a frequency (Ω0) and amplitude (a0) of oscillations of the output voltage (Vo[k]) of the DC-DC buck switching power converter;
update PID controller parameters based on the frequency (Ω0) and amplitude (ao) of the oscillations of the voltage output (Vo[k]) of the DC-DC buck switching power converter;
and
switch the controller circuit of the DC-DC buck switching power converter from a MRFT block to the PID controller.

8 more elements

Dependencies are inferred from the claim text.

Automatic tuning of a proportional-integral-derivative controller for dc-dc buck switching power converter

Life of this patent

Automatic tuning of a proportional-integral-derivative controller for dc-dc buck switching power converter

Life of this patent

Abstract

Claims18