Power quality improvement using PFC SEPIC converter for LED bulb adaptable for universal input voltage

SEPIC (Single Ended Primary Inductance Converter) is a dc-dc converter which can provide an output voltage either greater than or less than the input voltage. Basically it is similar to a buck-boost converter. The output voltage polarity of a SEPIC is non-inverted whereas the output voltage polarity is inverted in a buck-boost converter. SEPIC converters are widely used in battery operated equipment, power supplies for laptops and computers, power factor correction etc. Rapid development of computing technologies lead to great use of simulation tools for the planning and design of electrical systems. Nowadays complex electrical systems can be simulated with less time. There are mainly two types of simulations. One is offline simulation and other is real time simulation. In real time simulation both physical time and simulation time are same. Real time simulators are extensively used in many engineering fields. Statistical power grid protection tests, aircraft design and simulation, motor drive controller design methods and space robot integration are a few examples of real-time simulator technology applications. In this paper an average model of the SEPIC is derived at first. Then an offline simulation and real time simulation of SEPIC using miniature full spectrum simulator is explained.

ABSTRACTThis paper proposes quadratic-like single-ended primary inductance converter (SEPIC) converter, a DC/DC converter suitable for wide-input voltage range. This circuit can be gated at higher duty ratio compared with conventional SEPIC converter, while the voltage conversion ratio is low. This feature is beneficial for high-input voltage because it prevents the controller from falling into extremely low duty ratio limitation. A prototype circuit is implemented with Pulse-Width-Modulation (PWM) control to drive the Light emitting diode (LED) strings for demonstration of the circuit application. Recent studies have advocated LEDs as efficient and durable technology for lighting applications. A stabilized output converter is required to regulate the current flowing through the LED lamp. The dimming control of the LED light output is implemented by the controller. This converter can be powered from either a 24-Vdc battery or from the universal AC input voltage (up to 360 Vdc). Such a wide-input voltage application can be found in emergency lighting in which the light is possibly powered either from battery or AC input voltages. Experimental results prove the feasibility of the circuit topology and theoretical analysis.

This paper presents a high-efficiency power supply topology. The front stage is a power factor corrector (PFC) utilizing the single-ended primary inductor converter (SEPIC) topology. The presented SEPIC PFC is operated under continuous conduction mode (CCM) with a transition-mode (TM) PFC controller and coupled inductors. The input current waveform remains continuous to reduce the size of the EMI filter and increase the power density. Due to the inherent voltage step- up/down features of the SEPIC PFC, the input voltage of the post-stage half-bridge series resonant converter (HB-SRC) can be decreased to reduce the voltage stresses on the power switches. High efficiency and low cost can be achieved. Circuit topologies and design considerations for the studied high-performance power supply are analyzed and discussed in detail. High-efficiency requirements for the Energy Star standards can be satisfied. (6 pages)

A novel step-up/step-down DC-DC converter with improved voltage gain characteristics is suggested in this paper. The proposed converter combines flyback and single-ended primary inductance converter (SEPIC) converters. The voltage control loop design is simplified due to the use of only a single controlled switch. It has been discussed how switch duty cycle affects voltage gain. This relationship demonstrates that the proposed converter voltage gain is improved compared with flyback and SEPIC converters. However, compared to flyback and SEPIC converters, it has a higher voltage gain at any given duty cycle. The proposed converter operation is thoroughly discussed, the associated equations are derived, and its parameters are expertly designed. Moreover, it is designed to supply a DC load of 2.5 kW, 500 V, and 5 A. The proposed converter efficiency exceeds 84% under rated load conditions. Additionally, it is also presented as an adapter for electric vehicles. The waveforms associated with the simulation of the converter across the universal line voltage of 110-260 Vrms are shown. At both line voltages, the total harmonics distortions (THDs) of the line current are 17.12% and 27.26%, respectively. MATLAB/Simulink is utilized for validation in order to validate the topology for different applications.

This paper presents the regulation of the output voltage and inductor currents in a Single Ended Primary Inductor Converter (SEPIC), operating in the continuous conduction mode (CCM) using a sliding mode controller. Owing to the time varying nature of the SEPIC converter, designing a feedback controller is a challenging task. In order to improve the dynamic performance of the SEPIC, a Sliding Mode Controller (SMC) is developed. The developed SMC is designed by using a state space average model. The performance of the developed controller with the SEPIC converter is validated at different working conditions through Matlab simulations. It is also compared with the performance while using a PI controller. The results show that the designed controller gives very good output voltage regulation under different operating conditions such as a varying input voltage, changes in the load and component variations. A 48V, 46W experimental setup for has been developed in an analog platform to validate the performance of the proposed SMC.

In this paper, a (PF) Power factor correction and power quality (PQ) improvement based BLDC motor drive proposed. Normally the permanent magnet BLDC motor drive connected with the diode bridge rectifier and high value of the capacitor due to which poor power factor and higher THD (Total harmonic distortion) value at the input side To overcome this difficulty SEPIC (Single-ended primary inductance converter) converter use to optimize the PF and THD value. The converter operates in discontinuous conduction mode to get the desired result. This scheme also used for speed control of BLDC motor by controlling the VSI (voltage source inverter) feeding the BLDC drive.

The authors propose a simple and robust voltage controller to improve voltage dynamics in power factor corrected (PFC) converters. The conventional control of the PFC converters requires filtering of twice-the-line-frequency voltage ripples present on the DC bus voltage to reduce the total harmonic distortion (THD) in the input current. This filtering action significantly reduces the effective voltage regulation bandwidth, resulting in slow voltage dynamics. The proposed scheme cancels the voltage ripple on the DC bus voltage feedback path without any filtering action and thereby allows design of large bandwidth voltage control loop. This eliminates large overshoots and undershoots in output voltage during transients, which are prevalent in conventionally designed PFC converters. The controller design and implementation are described and simulation results are presented for single-phase boost PFC converter as well as single-phase voltage source PFC converter to demonstrate the feasibility of the proposed technique.

This paper presents modelling and simulation of artificial neuro-fuzzy inference system (ANFIS)-based maximum power point tracking (MPPT) algorithm for PV system with modified SEPIC converter. The conventional existing MPPT methods are having major drawbacks of high oscillations at maximum power point and low efficiency due to uncertain nature of solar radiation and temperature. These mentioned problems can be solved by the proposed adaptive (ANFIS)-based MPPT. The proposed work involves ANFIS and modified single ended primary inductor converter (SEPIC) to extract maximum power from PV panel. The results obtained from proposed methodology are compared with other MPPT algorithms such as perturb and observe (P&O), incremental conductance (INC) and radial basis function network (RBFN). The improvement in voltage rating of modified SEPIC is compared with conventional SEPIC converter. The result confirms the superiority of the proposed system.

Due to rising environmental challenges and complicated emission regulations, electric vehicles have been seen as an alternative to traditional transportation. Modern electric vehicles use electronic circuits powered by electrical energy (PECs). DC to DC converters and DC to AC inverters are both classed as PECs. DC to AC inverter: It delivers utility power while also driving electric motors; the DC to DC converter serves as a source of low voltage utility electricity. DC to DC converters are categorised according to application requirements. In order to charge a high-power electric load, an increase in output is needed. It is because of this that it uses the SEPIC converter. DC-DC converter designates the single-ended primary-inductor converter (SEPIC). The electrical potential may be any value, such as less than, equal to, or greater than the input voltage. Duty cycle of the control transistor governs the SEPIC output. In SEPIC, voltage conversion is accomplished by transferring energy between inductors and capacitors. SEPIC boost converter relates to buck-boost converter modification. Both are comparable. The SEPIC converter has a few benefits. They are non-inverted input- same polarity of input and output voltage, between output and input, energy is linked using a series capacitor- to a short circuit output, producing greater responsiveness, genuine shutdown is possible- output goes to 0V if switch is off. This converter is simple to control while operating in CCM mode. Because both switches use the same gating pulse, the duty cycle may be adjusted to obtain a broad range of output voltage. In terms of number of components, diode and switch voltage stress, and voltage gain, recent non-coupled inductor converters are compared to the proposed converter. With regard to output voltage, the suggested converter produces a lower proportion of voltage stress on switches. When compared to existing converters, the suggested converter produces a high voltage gain with fewer components.

This paper proposes a capacitor switching logic for a multi input Single Ended Primary Inductance Converter (SEPIC) with efficient Maximum Power Point Tracking (MPPT) scheme for multiple non aligned solar panels. The proposed scheme is an improvement of time division multiplexing control of multi input converters for low power solar energy harvesters. In the proposed design, the capacitor switching logic gives the flexibility of selecting panels on demand providing additional advantage of isolation. For better accuracy an efficient algorithm has been implemented for determining MPPT. The MPPT is practically determined in each cycle when the corresponding capacitor is connected to converter. Using SEPIC converter at the output provides a constant 15V for charging the battery for solar panel voltage range from 8V to 25V. The design improvements will bring increased efficiency for medium power solar systems.

This paper provides a modified single-ended primary inductor converter (SEPIC) with an asymmetrical switched inductor super lift cell (ASISLC) for renewable energy applications. Solar, fuel cells, and so on, provide low output voltage, which is not sufficient for high voltage dc grid or dc loads. Therefore, the existence of a high gain DC-DC converter is mandatory. The proposed converter provides high gain, high efficiency, and less voltage stress at a low duty cycle. The proposed converter incorporates switched inductor together with a super lift cell. The super lift cell has a charge pump capacitor is connected in an asymmetrical fashion. The proposed converter offers continuous current at the input together with the above-mentioned advantages. This paper explains the operation of the ASISLC SEPIC converter in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The operating principle, theoretical analysis, design process, and comparison of the suggested converters with converters from the literature that use similar operating principles are all discussed in this paper. A MATLAB simulation is done and their results are provided. Finally, a hardware prototype for 200W, 50 kHz switching frequency is built and their results are validated to authenticate the effectiveness of the proposed converter.

Compact Fluorescent Lamps (CFL) and Light Emitting Diode (LED) Lamps are increasingly becoming popular as energy saving lamps among the consumers due to their long lifetime, good luminous output and encouragement from the governments of many countries. LEDs and CFLs are reported to be less real power consuming, energy efficient and economic than their counterpart incandescent lamps. However, as nonlinear loads, LEDs and CFLs draw extremely distorted currents with poor power factor. Hence, a massive usage of LEDs and CFLs forlighting is likely to generate important power qualitycrisis as well as loss for the power companies. This paper reports the experimental results of harmonicanalysis up to 50th order, power factor and luminous efficiency in terms of lumen per watt for some widely used CFL, LED, fluorescent and incandescent lamps for indoor lighting. Experimental results show that LED could be more economical, higher luminous efficiency with lower harmonic absorbing lighting source than CFL, fluorescent and incandescent lamps.

In light-emitting diode (LED) lighting, the driver commands the lifetime and the LED bulb. It is essential to predict the driver's lifetime during its design stage. This paper proposes a viable method to predict the lifetime of the LED driver based on its failure rate. A novel single-ended primary inductor converter (SEPIC) integrated parallel ripple cancellation circuit (PRC) topology of 30 W is considered to estimate the lifetime of the driver circuit. The failure rate model is regarded as a base to predict the lifetime of LED drivers using Bayesian belief network (BBN) analysis. The weakest links are the prime components to estimate the lifetime, and they are active devices and capacitors employed in the driver circuit. The output capacitor is considered a degree of importance as per the existing literature, and the proposed course has been designed without using any electrolytic capacitor (EC) to enhance the reliability of the driver circuit. This approach ensures an effective way to access the mean time to failure (MTTF) or the lifetime of the LED driver in a lucrative manner.

This manuscript deals about the configuration of a power factor correction (PFC) converter feeding a drive of brushless DC (BLDC) motor for medium and low power equipment. The front-end PFC converter working in discontinuous inductor current mode (DICM) is applied for regulating the DC link voltage and PFC is achieved inherently. The BLDC motor speed is adjusted by regulating the DC link voltage of voltage source inverter (VSI) feeding to motor. The DC link voltage of drive system is maintained by a single DC voltage actuator. A prototype is developed for evaluating the performances of anticipated drive for the speed control over a broad range. The performance of anticipated drive is also validated for its function at varying AC mains voltages (90V–265V). Test results for power quality (PQ) parameters are compared with restrictions of power quality standard IEC 61000-3-2.

Dynamic response of boost power factor correction (PFC) converter operating in continuous-conduction mode (CCM) is heavily influenced by low-bandwidth of voltage control loop. A novel tri-state boost PFC converter operating in pseudo-continuous-conduction mode (PCCM) is proposed in this paper. An additional degree of control-freedom introduced by a freewheeling switching control interval helps to achieve PFC control. A simple and fast voltage control loop can be used to maintain a constant output voltage. Furthermore, compared with boost PFC converter operating in conventional discontinuous-conduction mode (DCM), boost PFC converter operating in PCCM demonstrates greatly improved current handling capability with reduced current and voltage ripples. Analytical and simulation results of the tri-state boost PFC converter have been presented and compared with those of the boost PFC converter operating in conventional CCM and DCM. Simulation results show excellent dynamic performance of the tri-state boost PFC converter.