Performance Evaluation of Bridgeless Buck-boost LED Driver Circuit with Linear Active Disturbance Rejection Control
Light emitting diode (LED) based illumination has outshone its conventional alternatives because of its advantages. While operating the LEDs from an AC power supply, LED driver circuits should ensure that the supply current is drawn at unity power factor (UPF) along with the supply of a regulated current to the load. This paper discusses a bridgeless buck-boost power factor correction (BL-BBPFC) topology, which can provide an output voltage varying over a range both higher or lower than the peak supply voltage. It is considered that the topology operates in the discontinuous current conduction mode (DCM), which reduces the control complexity to a single loop control. Further, a linear active disturbance rejection control (LADRC) scheme is used for the regulation of the load. In this scheme, the control law is formulated using the estimated states of the system. The modeling uncertainties and external disturbances are eliminated using an extended state observer (ESO). The work presented here extends the concept of LADRC to the power factor correction (PFC) circuits and evaluates performance based on time and frequency domain parameters.