Systems and methods for voltage compensation based on load conditions in power converters

A system controller for regulating a power converter, the system controller comprising:

• a first controller terminal;
• a second controller terminal;
• and
• a compensation current generator;
• wherein the compensation current generator is configured to:
• receive an input signal through the first controller terminal, the input signal indicating a first current flowing through a primary winding of a power converter;
• receive a demagnetization signal related to a demagnetization period of the power converter and associated with an auxiliary winding of the power converter;
• generate a compensation current based at least in part on the input signal and the demagnetization signal;
• generate a compensation voltage based at least in part on the compensation current;
• and
• output a first reference voltage based at least in part on the compensation voltage and a second reference voltage;
• and
• wherein the first reference voltage is equal to a sum of the compensation voltage and the second reference voltage.

A system controller for regulating a power converter, the system controller comprising:

• a first controller terminal;
• a second controller terminal;
• a compensation current generator;
• and
• an error amplifier;
• wherein the compensation current generator is configured to:
• receive an input signal through the first controller terminal, the input signal indicating a first current flowing through a primary winding of a power converter;
• receive an amplified signal;
• and
• generate a compensation current based at least in part on the input signal and the amplified signal;
• wherein the error amplifier is configured to:
• generate the amplified signal based on at least information associated with the compensation current;
• and
• output the amplified signal to the compensation current generator;
• and
• wherein the compensation current generator is further configured to generate the compensation current so that an output voltage of the power converter is independent of an output current of the power converter, the output voltage and the output current being related to a secondary winding of the power converter coupled to the primary winding.

A method for regulating a power converter, the method comprising:

• receiving an input signal, the input signal indicating a first current flowing through a primary winding of a power converter;
• receiving a demagnetization signal related to a demagnetization period of the power converter and associated with an auxiliary winding of the power converter;
• generating, by a compensation current generator, a compensation current based at least in part on the input signal and the demagnetization signal;
• generating, by the compensation current generator, a compensation voltage based at least in part on the compensation current;
• and
• outputting, by the compensation current generator, a first reference voltage based at least in part on the compensation voltage and a second reference voltage;
• wherein the first reference voltage is equal to a sum of the compensation voltage and the second reference voltage.

A method for regulating a power converter, the method comprising:

• receiving an input signal, the input signal indicating a first current flowing through a primary winding of a power converter;
• receiving an amplified signal;
• and
• generating, by a compensation current generator, a compensation current based at least in part on the input signal and the amplified signal;
• generating the amplified signal based on at least information associated with the compensation current;
• and
• outputting the amplified signal to the compensation current generator;
• wherein the generating, by a compensation current generator, a compensation current comprises generating the compensation current so that an output voltage of the power converter is independent of an output current of the power converter, the output voltage and the output current being related to a secondary winding of the power converter coupled to the primary winding.