LED A LED lighting device with the power supply equipped with a plurality of converters

摘要

The present invention relates to an LED lighting device having a power supply device embedded with a plurality of converters, which uses a method of two converters connected in parallel, applies a flyback converter to a PFC converter to generate a current waveform proportional to an input voltage, and removes a ripple component with a bidirectional converter. The LED lighting device of the present invention comprises: a power supply unit for receiving AC power; a rectifying unit for rectifying the AC power to output DC power; a PFC converter for supplying the DC power in a discontinuous conduction mode by a PWM control signal; a bidirectional converter connected in parallel with an output of the PFC converter, and removing a ripple component from an output current of the PFC converter; a control unit for sensing the output current of the PFC converter, comparing the sensed signal with a reference signal using the sensed signal as a feedback signal, generating a first PWM control signal (Q) and a second PWM control signal (Q1, Q2) as a result thereof, and separately inputting the same into the PFC converter and the bidirectional converter to control the same; an LED module including at least one LED; and an LC filter provided between the PFC converter and the LED module, and including a filter capacitor and a filter inductor. Accordingly, according to the present invention, a current waveform proportional to an input voltage is generated to further improve a power factor and to reduce THDi. Also, a ripple component is removed to supply a constant current to an LED module, and thus, a low capacity is used instead of a high electrolytic capacitor, thereby stably improving the performance and lifespan of the LED lighting device.