Method and system for eliminating certain harmonics in a distributed power system

A harmonic feedback system comprising:

• a three-phase to two-phase transformer configured to convert an output fundamental frequency current from a distributed power system and to convert the output fundamental frequency current from a three-phase current to a two-phase stationary reference current;
• a harmonic frequency transformer configured to convert the two-phase stationary reference current to a synchronous reference current, said harmonic frequency transformer having a target synchronous reference frame frequency based upon a reference harmonic current of the output fundamental frequency current;
• at least one filter device configured to remove predetermined components from the synchronous reference current to output a harmonic feedback current;
• and
• a summation component to compare the harmonic feedback current with the reference harmonic current and to output a harmonic error current for driving the distributed power system to produce the output current.

A method of eliminating certain harmonics in a distributed power system, wherein the power system comprises a fundamental current regulating signal, comprising:

• receiving an output fundamental frequency current from a inverter;
• transforming the output fundamental frequency current from a stationary reference frame to a synchronous reference frame, where the synchronous reference frame frequency is based upon a reference harmonic current of the output fundamental frequency current;
• filtering predetermined frequency components from a transformed version of the output current to obtain harmonics feedback current;
• comparing the harmonics feedback current with a reference harmonics current to obtain a harmonics error current;
• regulating the harmonics error current to generate a harmonic current regulating signal;
• and
• adding the harmonic current regulating signal to a fundamental current regulating signal to form a combined regulating signal.

A method of eliminating certain harmonics in a distributed power system, comprising:

• receiving a fundamental frequency current from an output of a power inverter, wherein the power inverter is connected to a nonlinear end load;
• creating a harmonic feedback current by transforming the fundamental frequency current to a target synchronous reference frame, where the target synchronous reference frame frequency is based on a harmonic current of the fundamental frequency current;
• providing a harmonic error current by summing the negative of the harmonic feedback current and an associated reference harmonic current;
• regulating the harmonic error current to generate a harmonic current regulating signal;
• transforming the harmonic current regulating signal to a reference frame of a fundamental current regulating signal in the power inverter;
• and
• summing the harmonic current regulating signal and the fundamental current regulating signal in the power inverter.