Droop current sharing power converter with controlled transitions between regulation set points

A method of operating a regulated switching power converter generating a converter output having distinct first and second regulated output values under corresponding distinct operating conditions, operation employing a regulation reference value for a regulation feedback loop, the converter output transitioning between the first and second regulated output values in response to corresponding transition of a trigger signal in a transition window between first and second trigger values, comprising:

• defining a transition step function based on respective values for transition amplitude, transition interval and number of steps n, the transition amplitude being a difference between the first and second regulated output values, and the transition interval being a difference between the first and second trigger values, the transition step function generating a step-like transition signal having n steps and being based on ranges of values of the trigger signal between the first and second trigger values;
• and
• during operation with the trigger signal having a value in the transition window, including the step-like transition signal in the regulation reference value to generate a step-like transition of the converter output between the first and second regulated output values,
• wherein the regulated switching power converter employs a programmable digital controller, and wherein the trigger signal is an output of a trigger algorithm executed by the programmable digital controller,
• wherein the trigger algorithm employs a seeking algorithm causing the regulated switching power converter to automatically move to new set points in discrete regulating steps to find an optimum operating point based on measured operating parameters,
• wherein the seeking algorithm includes a droop positioning algorithm to find a desired operating point on a load line of the regulated switching converter,
• and wherein the desired operating point is one of (a) a relief point of lower output current away from a point of a current limit, and (b) a point of desired current balance among a set of power converters including the regulated switching converter in which respective input voltages to different power converters are nominally equal but sufficiently offset from each other to cause current imbalance but for an effect of the droop positioning algorithm.

A method of operating a regulated switching power converter generating a converter output having distinct first and second regulated output values under corresponding distinct operating conditions, operation employing a regulation reference value for a regulation feedback loop, the converter output transitioning between the first and second regulated output values in response to corresponding transition of a trigger signal in a transition window between first and second trigger values, comprising:

• defining a transition step function based on respective values for transition amplitude, transition interval and number of steps n, the transition amplitude being a difference between the first and second regulated output values, and the transition interval being a difference between the first and second trigger values, the transition step function generating a step-like transition signal having n steps and being based on ranges of values of the trigger signal between the first and second trigger values;
• and
• during operation with the trigger signal having a value in the transition window, including the step-like transition signal in the regulation reference value to generate a step-like transition of the converter output between the first and second regulated output values,
• wherein the regulated switching power converter employs a programmable digital controller, and wherein the trigger signal is an output of a trigger algorithm executed by the programmable digital controller,
• wherein the trigger algorithm employs a seeking algorithm causing the regulated switching power converter to automatically move to new set points in discrete regulating steps to find an optimum operating point based on measured operating parameters,
• wherein the seeking algorithm includes a droop positioning algorithm to find a desired operating point on a load line of the regulated switching converter,
• and wherein the desired operating point is one of (a) a relief point of lower output current away from a point of a current limit, and (b) a point of desired current balance among a set of power converters including the regulated switching converter in which respective output currents from different power converters are nominally balanced by a selected droop impedance but, due to different distribution impedances relative to a point of load, are sufficiently offset from each other to cause current imbalance but for an effect of the droop positioning algorithm.