Photovoltaic power converter system with a controller configured to actively compensate load harmonics

A controller for a photovoltaic power converter system including a photovoltaic array coupled to an inverter to generate an output current for energizing a load connected to said inverter, said controller comprising:

• a first circuit coupled to receive a load current and separate out a harmonic component from the load current and to measure a harmonic current;
• a second circuit for determining an amplitude of an injectable current available from the photovoltaic array to generate a fundamental sinusoidal current reference that is phased locked with a mains grid supply voltage;
• and
• a third circuit for combining the load harmonic current and the fundamental sinusoidal current reference to generate a command output signal,
• wherein the controller is configured to generate an error signal based on a difference between the command output signal and the output current, and
• wherein the controller is configured to process the error signal and to generate a switching signal for actuating a switching gate of said inverter to compensate for the load harmonic current when said inverter injects the output current to the mains grid supply voltage.

A method for controlling a photovoltaic power converter system including a photovoltaic array coupled to an inverter to generate an output current for energizing a load connected to said inverter, said method comprising:

• receiving a load current to separate out a harmonic component from the load current and to measure a load harmonic current;
• determining an amplitude of an injectable current available from the photovoltaic array and generating a fundamental sinusoidal current reference that is phase locked with the mains grid supply voltage;
• and
• combining the load harmonic current and the fundamental sinusoidal current reference to generate a command output signal,
• whereby the controller is configured to generate an error signal based on a difference between the command output signal and the output current, and
• whereby the controller is configured to process the error signal and to generate a switching signal for actuating a switching gate of said inverter to compensate for the load harmonic current when said inverter injects the output current to the mains grid supply voltage.