Load sharing between parallel connected power converters

A method of sharing load among a plurality of power converters, each power converter having an input and an output, wherein the outputs of the power converters are connected together in parallel to produce a single system output, the method comprising:

• generating a current command signal in a control loop in a designated one of the power converters;
• outputting the current command signal to a shared command bus that is coupled to each one of the power converters;
• receiving the current command signal from the shared command bus at all of the parallel connected power converters in the power supply system;
• and
• adjusting an amount of electrical current being supplied by each respective one of the power converters in response to the received current command signal,
• wherein the control loop comprises a proportional-integral control loop, and wherein generating the current command signal comprises:
• producing an output from the proportional-integral controller given by:
• KPΔ+KI∫Δdt
• where Kp is a proportional gain coefficient, KI is an integral gain coefficient, and Δ represents an error between an actual measured voltage at the single system output and a desired voltage at the single system output.

A power supply system comprising:

• a plurality of power converters, each power converter having an input and an output, wherein the outputs of the power converters are connected together in parallel to produce a single system output;
• a shared command bus coupled to each one of the power converters,
• a control loop in a designated one of the power converters for generating a current command signal to be outputted onto the shared command bus,
• wherein all of the parallel connected power converters in the power supply system are configured to receive the current command signal from the shared command bus and adjust an amount of electrical current being supplied by that power converter in response to the current command signal,
• wherein each power converter comprises:
• a power stage circuit to convert an input voltage to an output voltage;
• a regulator circuit;
• a command output buffer;
• a command input buffer;
• a select and load circuit;
• and
• a power control circuit.

A method of sharing load among a plurality of power converters, each power converter having an input and an output, wherein the outputs of the power converters are connected together in parallel to produce a single system output, the method comprising:

• generating a current command signal in a control loop in a designated one of the power converters;
• outputting the current command signal to a shared command bus that is coupled to each one of the power converters;
• receiving the current command signal from the shared command bus at all of the parallel connected power converters in the power supply system;
• and
• adjusting an amount of electrical current being supplied by each respective one of the power converters in response to the received current command signal,
• wherein each power converter comprises a power stage circuit to convert an input voltage to an output voltage, a regulator circuit, a command output buffer, a command input buffer, a select and load circuit, and a power control circuit,
• the method further comprising, in the power converter that is designated as a primary master power converter:
• monitoring the output voltage of the power stage circuit;
• producing the current command signal with the regulator circuit, and;
• allowing, with the command output buffer, the current command signal to exit the power converter to the shared command bus;
• causing, with the select and load circuit, the command output buffer to allow the current command signal to exit the power converter and enter the shared command bus;
• producing, with the select and load circuit, a control signal for the power control circuit, and
• controlling, from the power control circuit, the power stage based on the control signal from the select and load circuit.

A method of sharing load among a plurality of power converters, each power converter having an input and an output, wherein the outputs of the power converters are connected together in parallel to produce a single system output, the method comprising:

• generating a current command signal in a control loop in a designated one of the power converters;
• outputting the current command signal to a shared command bus that is coupled to each one of the power converters;
• receiving the current command signal from the shared command bus at all of the parallel connected power converters in the power supply system;
• and
• adjusting an amount of electrical current being supplied by each respective one of the power converters in response to the received current command signal,
• wherein each power converter comprises a power stage circuit to convert an input voltage to an output voltage, a regulator circuit, a command output buffer, a command input buffer, a select and load circuit, and a power control circuit, the method further comprising, in any of the power converters designated as a slave power converter:
• allowing, with the command input buffer, the current command signal to enter the power converter from the shared command bus;
• producing, with the select and load circuit, a control signal for the power control circuit based on the current command signal, and
• controlling, with the power control circuit, the power stage based on the control signal from the select and load circuit.