Power supply apparatus

A power supply apparatus, comprising:

• a power factor correction circuit configured to convert a DC link voltage into a first voltage;
• an LLC converter comprising a primary side circuit and a secondary side circuit, which are coupled with each other, wherein the primary side circuit is electrically connected with the power factor correction circuit to receive the first voltage, the first voltage is converted into a second voltage by the LLC converter, and the second voltage is outputted from the secondary side circuit;
• an auxiliary conversion circuit electrically connected with the power factor correction circuit and configured to convert the first voltage into an auxiliary voltage;
• a secondary side controller disposed on a secondary side of the LLC converter and configured to control operations of the LLC converter;
• and
• a voltage tracking circuit electrically connected to the auxiliary conversion circuit and configured to detect the auxiliary voltage and issue a detection signal to the secondary side controller according to a result of detecting the auxiliary voltage,
• wherein according to the detection signal, the secondary side controller tracks a ripple change of the DC link voltage and instantly generates a reverse waveform opposite to a waveform of the DC link voltage, wherein the secondary side controller controls the operations of the LLC converter according to the reverse waveform, so that secondary side voltage ripples of the DC link voltage are suppressed;
• wherein the auxiliary conversion circuit comprises a transformer, and the transformer comprises a primary winding, a first secondary winding and a second secondary winding, wherein a first terminal and a second terminal of the primary winding are electrically connected with the power factor correction circuit, the primary winding is reversely coupled with the first secondary winding and the second secondary winding, a first terminal of the first secondary winding is electrically connected with a ground terminal, a second terminal of the first secondary winding is electrically connected with the voltage tracking circuit, and the auxiliary voltage is outputted from the second terminal of the first secondary winding.