Design and Implementation of 150 W AC/DC LED Driver with Unity Power Factor, Low THD, and Dimming Capability

Abstract

This paper presents the implementation of a two-stage light-emitting diode (LED) driver based on commercial integrated circuits (IC). The presented LED driver circuit topology, which is designed to drive a 150 W LED module, consists of two stages: AC-DC power factor correction (PFC) stage and DC/DC power converter stage. The implementation of the PFC stage uses IC NCP1608, which uses the critical conduction mode to guarantee a unity input power factor with a wide range of input voltages. The DC/DC power converter with soft-switching characteristics for the entire load range uses IC FLS2100XS. Furthermore, the design of an electromagnetic interference (EMI) filter for the LED driver and the dimming control circuit are discussed in detail. The hardware prototype, an LED lighting system, with a rated power of 150 W/32 V from a nominal 220 V/50 Hz AC voltage supply was tested to show the effectiveness of the design. The presented LED driver was tested for street lighting, and the experimental results show that the power factor (PF) was higher than 0.97, the total harmonics distortion (THD) was lower than 7%, and the efficiency was 91.7% at full load. The results prove that the performance of the presented LED driver complies with the standards: IEC61000-3-2 and CIRSP 15:2009. Electronics 2020, 9, 52 2 of 22There are three types of LED driver systems: Single-stage [10,11], two-stage [12][13][14], and integrated LED drivers [15,16]. The single-stage LED driver is an AC/DC converter that provides a constant output current for the LED and a unity power factor. The two-stage system consists of two separate stages, an AC/DC power factor correction (PFC) converter and a DC/DC converter. Recently, some integrated topologies were introduced in order to reduce the size and cost. Single-stage and integrated solutions have some advantages such as low-cost designs and high efficiency due to only one energy conversion. However, the PFC of these topologies causes a high-output voltage ripple due to the absence of electrolytic capacitors. Hence, the low-frequency current ripple makes LEDs flicker. These single-stage and integrated solutions are not suitable LED street lighting systems and are instead used for LED-based replacement lamps where small-size converters are needed. Furthermore, the bridgeless topologies usually generate high electromagnetic interference (EMI) due to large dv/dt and di/dt. The two-stage topology is the most popular topology for LED drivers above 100 W [17]. In the two-stage LED driver, the constant output current regulation is more easily implemented due to the bus voltage. Additionally, an isolated DC-DC stage is needed in the LED driver in order to ensure constant current control.Recently, there have been several commercial analog integrated circuits (ICs) available on the market that are recommended for a high power factor and low cost with a high efficiency. These commercial ICs fulfil the IEC 1000-3-2 Class C, but the total harmonics distortion (THD) is higher than 20% [18]. In reference [19], a reson...

Passive and Active Topologies Investigation for LED Driver Circuits

“…The input capacitor C in is useful for further improvement of the input power factor. The use of a power factor correction capacitor C in is a standard method used in the magnetic ballast in the case of fluorescent lamps [18].…”

Latest Developments in LED Drivers

“…Due to the fact that single-phase ac mains is the primary power supply in homes, offices, streets, etc., ac-dc LED drivers are required to ensure good performance and compliance with regulations (i.e., efficiency, rated life-time hours, harmonic injection, dimming performance and flicker free operation). Paper [7] presents a very practical approach to the classic two-stage solution for ac-dc LED drivers using commercial ICs. The first stage is a boost converter (i.e.…”

Design, Analysis, and Implementation of an Equalizer Circuit for the Elimination of Voltage Imbalance in a Half-Bridge Boost Converter with Power Factor Correction

“…Power Factor General aspects about power quality, power factor and harmonic distortion in electrical systems [1][2][3][4][5][6][7] Converters PFC Provision of a general description of PFC converters, cascade buck-boost,Ćuk converter, flyback circuit, and boost converter [6,[8][9][10][10][11][12] Fuzzy logic control PFC converter control using fuzzy logic in the application to supply power to a fed brushless DC motor [13] Predictive control Predictive control application for PFC converters, the system calculates the future value of the duty cycle [11,14] Digital Controller It shows a brief review of different applications of converters using digital controllers [15][16][17][18][19][20] LED applications Application of PFC converters for LED lighting using full-bridge and half-bridge rectifiers [21][22][23] Photovoltaic applications Description of the application of PFC converters in photovoltaic systems [17,24] Voltage Imbalance Describe main works related to the imbalance in half-bridge rectifiers. This issue is addressed in this work [25][26][27][28] Power Factor Correction This article focuses on showing that the proposed topology allows the reduction of the capacitor imbalance in a half-bridge boost converter.…”

“…The inductors coupled in the interleaved PFC buck-boost converter operate in discontinuous conduction mode to achieve PFC. Additional work can be seen in [23] that presents the implementation of a two-stage light-emitting diode driver. The LED driver circuit design drives a 150 W LED module.…”