Paulo C. V. Luz

Single-stage SEPIC-Buck converter for LED lighting with reduced storage capacitor

This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to eliminate/substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a film capacitor, increasing the system lifetime. This reduction is based on designing of the control dynamic with a compromise between the input current distortion and the output current ripple. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) because of its intrinsic low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Buck converter using its output current source behavior, suitable for LED application. A 100 W LED driver prototype is implemented resulting in a 6.9% total harmonic distortion (THD) and 30% current ripple on the LED.

Long-lifetime SEPIC-buck integrated converter for LED lighting application

This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to eliminate/substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a film capacitor, increasing the system lifetime. This reduction is based on designing of the control dynamic with a compromise between the input current distortion and the output current ripple. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) because of its intrinsic low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Buck converter using its output current source behavior, suitable for LED application. A 100 W LED driver prototype is implemented resulting in a 6.9% total harmonic distortion (THD) and 30% current ripple on the LED.

Off-line single-stage SEPIC-Buck converter for dimmable LED lighting with reduced storage capacitor

This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a longer lifetime capacitor, increasing the overall system life span. A Proportional Integral (PI) controller is designed to reduce the output current ripple. Consequently, it reduces the bus voltage which allows working with reduced bus capacitances. The input current distortion limit must be observed. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) operating under discontinuous conduction mode (DCM) because of its low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Buck converter using its output current source behavior, suitable for LED application. A 107 W LED driver prototype is implemented resulting in 15.2% total harmonic distortion (THD), 50% current ripple on the LED and an efficiency of 90.1% using a 35μF bus film capacitor. Furthermore a dimming strategy is proposed and implemented by an LED parallel active switch.

An integrated insulated buck-Flyback converter to feed LED's lamps to street lighting with reduced capacitances

This paper presents the project of an integrated insulated converter to feed a LEDs lamp to street lighting systems. An integrated Buck-Boost-Flyback was designed, as well a control technique to reduce the capacitances value and the paper also presents the parameters and experimental results of the integrated converter.

An integrated insulated Buck-Boost-Flyback converter to feed LED's lamps to street lighting with reduced capacitances

This paper presents the project of an integrated insulated converter to feed a LEDs lamp to street lighting systems. An integrated Buck-Boost-Flyback was designed, as well a control technique to reduce the capacitances value and the paper also presents the parameters and experimental results of the integrated converter.

HID electronic ballast based on bi-flyback inverter topology

This paper presents an electronic ballast to supply a 70W high pressure sodium lamp. The electronic ballast consists on a single-stage converter that integrates a buck converter to provide power factor correction and two flyback converters to supply the lamp, with low frequency square waveform, in order to avoid the acoustic resonance phenomenon occurrence. It is proposed one study, qualitative and quantitative, of active converters to provide the power factor correction, and their integration with the bi-flyback inverter topology. Buck bi-flyback inverter topology is chosen to the implementation of practical experiments, in order to validate the present work.

Self-Oscillating electronic ballast with lighting intensity regulation

This paper presents electronic ballast with dimming capability supplying a 32 W fluorescent lamp. The electronic ballast is a self-oscillating driving circuit and an additional circuit responsible to dimming the fluorescent lamp using a lighting dependent resistor. This luminous sensor measures the luminous flux level and set the lamp power through the voltage gain variation of the resonant filter based on a feedforward control. Simulation and experimental results of the proposed electronic ballast are presented to demonstrate the feasibility of the system.

Comparative analysis among three switched capacitor converters to feed a LED tubular lamp

This paper presents an analysis among three converters that use switched capacitors applied to feed a LED tubular lamp. These converters are designed and simulated and the main results are shown. LED tubular lamps can replace fluorescent tubular lamps with some benefits, such as longer lifetime and less energy consumption. The LED tubular lamp used has power of 23 W, current of 450 mA, input voltage of 220 Vrms, 60 Hz. A topology is proposed aiming to feed the LEDs with the correct current ripple (according to the recommendations). These converters must have high power factor and high efficiency.

Isolated topologies family for street lighting using LED as source light

This paper presents a family of insulated drivers to feed LED lamps to street lighting system. Aiming increase the lifetime of the LED driver, this work presents a PI controller to reduce the capacitance value and replace the electrolytic capacitor by another technology of capacitor with longer lifetime. Four isolated converters topologies are presented and analyzed. Experimental results are presented for all proposed topologies. All of them present high power factor, low THD and comply with the IEC 61000-3-2 standard.

Dimmable single-stage SEPIC-Ćuk converter for LED lighting with reduced storage capacitor

This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a longer lifetime capacitor, increasing the overall system life span. This reduction is based on designing a control dynamic with a compromise between the input current distortion and the output current ripple. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) because of its intrinsic low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Ćuk converter using its output current source behavior in Continuous Conduction Mode (CCM), suitable for LED application. Furthermore a dimming strategy is also proposed and implemented by an LED parallel active switch.