High-power-density dimming power supply and control method thereof

A high-power-density dimming power supply, comprising:

• an outer housing (100) and a control circuit board (200), wherein the outer housing (100) comprises a control panel (110) and a rear housing (120), the control circuit board (200) is disposed in a space defined by the control panel (110) and the rear housing (120), a control device is disposed on the control panel (110), a control circuit is disposed on the control circuit board (200), an input terminal and an output terminal are disposed on the rear housing (120), the control circuit comprises a rectification filtering circuit, a power factor correction circuit, a direct current (DC)-DC power conversion circuit, an output control circuit and a main control circuit, an input end of the rectification filtering circuit is electrically connected with commercial power through the input terminal, an output end of the rectification filtering circuit is electrically connected with an input end of the power factor correction circuit, an output end of the power factor correction circuit is electrically connected with an input end of the DC-DC power conversion circuit, an output end of the DC-DC power conversion circuit is electrically connected with an input end of the output control circuit, the DC-DC power conversion circuit supplies electricity to the main control circuit, an output end of the output control circuit is electrically connected with a lamp load through the output terminal, the output control circuit is controlled by the main control circuit, the control device is electrically connected with the main control circuit, the DC-DC power conversion circuit uses a soft switching circuit architecture, a working frequency of the DC-DC power conversion circuit is set to be a value above 110 KHz, the control circuit board (200) comprises a main board (210) and a plurality of sub boards (220) vertically disposed on the main board (210), electronic components in the control circuit are distributed on the main board (210) and the sub boards (220), and in a case that the power factor correction circuit is in a continuous conduction mode, a working frequency of the power factor correction circuit is above 75 KHz;
• or in a case that the power factor correction circuit is in a critical conduction mode, the working frequency near a zero crossing point is not limited, and in a case that a voltage is above 1/2 of a wave peak voltage of alternating current, the working frequency of the power factor correction circuit is set to be a value above 75 KHz.