Power supply apparatus and apparatus and method for controlling switched-mode power supply (smps)

A power supply apparatus comprising:

• a pulse voltage generating unit generating a first pulse voltage having a positive level of an average voltage and a second pulse voltage having a negative level of an average voltage;
• a first low pass filter filtering the first pulse voltage to output a positive direct current (DC) voltage;
• a second low pass filter filtering the second pulse voltage to output a negative DC voltage;
• a sensing unit sensing a level of the positive DC voltage of the first low pass filter or a level of the negative DC voltage of the second low pass filter and sensing a level of an output current of the first low pass filter or a level of an output current of the second low pass filter;
• a calculating unit calculating an amount of output power based on the level of the DC voltage and the level of the output current sensed by the sensing unit;
• and
• a controlling unit controlling a duty ratio of the pulse voltage based on the amount of output power calculated by the calculating unit and an amount of reference power.

An apparatus for controlling a switched-mode power supply (SMPS), the apparatus comprising:

• a sensing unit sensing a level of a direct current (DC) voltage and a level of an output current of SMPS;
• a calculating unit calculating an amount of output power based on the level of the DC voltage and the level of the output current sensed by the sensing unit;
• a controlling unit controlling the SMPS to change the level of the DC voltage based on the amount of output power calculated by the calculating unit and an amount of reference power;
• a storing unit storing an amount of output power prior to a level of the DC voltage being changed by the controlling unit;
• and
• a comparing unit comparing an amount of output power subsequent to a level of the DC voltage being changed by the controlling unit, with the amount of output power stored in the storing unit,
• wherein in a case in which the amount of output power subsequent to the level of the DC voltage being changed is greater than the amount of output power prior to the level of the DC voltage being changed, the controlling unit operates in a first mode, and in a case in which the amount of output power subsequent to the level of the DC voltage being changed is less than the amount of output power prior to the level of the DC voltage being changed, the controlling unit operates in a second mode.

A method for controlling a switched-mode power supply (SMPS), the method comprising:

• sensing a level of a direct current (DC) voltage and a level of an output current of SMPS;
• calculating an amount of output power based on the level of the DC voltage and the level of the output current sensed in the sensing of the DC voltage;
• comparing the amount of output power calculated in the calculating with amounts of a plurality of different supplies of reference power;
• and
• determining a variation level of the DC voltage based on a result of the comparing of the amount of output power with the amounts of the plurality of different supplies of reference power and controlling the SMPS to change the level of the DC voltage.