Abstract: A system including a proportional-integral-derivative (PID) controller, a modified relay feedback test (MRFT) block, a memory block, a biasing block, a dq0-to-abc transformation block, a switch configured to selectively couple output signal of the biasing block or the PID controller output signal to the input of the dq0-to-abc transformation block, a three phase digital pulse width modulator, electronic switches, a voltage sensor configured to measure the output of each voltage of the three phases on the load and produce voltage data signals (Vob, Vob, Voc), and an abc-to-dq0 transformation block having an input being a representative of the phase voltages on the load, and producing an output being a representative of these voltages in the dq0 format.

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 (?) 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 (?0) and amplitude (?0) of the output voltage (Vo[k]), updating PID controller parameters based on the frequency (?0) and amplitude (?0), and substituting the MRFT (104) with the PID controller (102

Abstract: A bi-directional DC voltage converter includes a controller, controlled switches, inductors, and capacitors to accomplish DC voltage conversion with minimal input current ripple and high efficiency. The controller is operable in a boost mode in which the switches are independently controlled to convert low-voltage DC power to high-voltage DC power. The controller is operable in a buck mode in which the switches are independently controlled to convert high-voltage DC power to low-voltage DC power.