Single-ended Primary Inductance Converter Power Research Articles

Zero‐voltage transition bridgeless single‐ended primary inductance converter power factor correction rectifier

In this study, a new zero-voltage transition (ZVT) bridgeless single-ended primary inductance converter power factor correction converter is introduced. The proposed converter has only two semiconductor elements in the current path at any time. Therefore the conduction losses in this converter are reduced in comparison with conventional SEPIC PFC rectifier. Also, in the proposed converter, ZVT soft switching technique is applied to improve the efficiency. The principle of the operation, design procedure and simulation results are presented. A 450 W prototype of this converter is implemented and the experimental results are presented to demonstrate the feasibility of the proposed technique.

Modeling and multi-loop feedback control design of a SEPIC power factor corrector in single-phase rectifiers

In this paper, a comparative analysis of three multi-loops control schemes dedicated to the single ended primary inductance converter (SEPIC) power factor corrector (PFC) is presented. The first control technique uses a robust hysteresis current controller; the second control strategy consists of a frequency–domain linear design of regulators on the basis of a small-signal averaged model of the converter, whereas the third control design method uses the input/output feedback linearization approach applied on the large-signal state-space averaged model of the converter. In order to verify and compare the performance of all control schemes, numerical simulations are carried out on a switching-functions-based model of the converter, which is implemented using Matlab/Simulink. The control systems are tested under both rated and disturbed operating conditions. The systems performance is evaluated in terms of source current total harmonic distortion (THD), input power factor, and DC voltage regulation toward load disturbances.

Modelling, design and control of a SEPIC power factor corrector for single-phase rectifiers: experimental validation

In this paper, a new general case switching-function-based model is proposed for a DC-to-DC single ended primary inductance converter (SEPIC). Compared to conventional buck or boost converters, this topology allows a low current ripple at the input for a relatively low level of the DC-bus voltage. The converter is used as a power factor correction (PFC) circuit for a single-phase rectifier and, based on the obtained model, steady-state analysis is performed and new design criteria were established for a proper selection of the inductors and capacitors. In order to verify the performance of the converter in PFC applications, a simple hysteretic-based feedback control is implemented and verified through simulations. For validation purpose, experiments are carried out on a 1kW laboratory prototype of the converter. The system performance is evaluated in terms of source current total harmonic distortion (THD), voltage regulation, robustness and dynamic behaviour.

Design and Implementation of a Photovoltaic High-Intensity-Discharge Street Lighting System

This paper presents a photovoltaic (PV) high-intensity-discharge (HID) street lighting system. A single-ended primary inductance converter (SEPIC) is studied for maximum power point tracking (MPPT) and battery charging. High conversion efficiency and high MPPT accuracy can be achieved under different atmospheric conditions. A pulse-current-charging scheme with an adaptive rest-period is also applied to avoid battery overcharging. An electronic ballast circuit is also designed to release the solar energy stored in battery for powering HID lamps. The studied PV HID street lighting system is connected to the ac-line utility with a SEPIC power factor correction converter. High input power factor can be achieved when energy is drawn from the ac-line utility to drive the HID lamp and to prevent the battery from over-discharging. The proposed PV HID street lighting system has the advantages of high power density, simple circuit, and long lifetime. The operating principle and design considerations were analyzed and discussed in detail. A laboratory prototype was implemented and tested. The experimental results were shown to verify the feasibility of the proposed scheme.

Modeling and simulation of a new Bridgeless SEPIC power factor correction circuit

A new Bridgeless PFC circuit based on Single-Ended Primary Inductance Converter (SEPIC) is proposed in this paper. The new topology has less component count and less conducted component during each mode of operation within one switching period. The small-signal and steady-state model of the circuit operated in Discontinuous Conduction Mode (DCM) is derived using the Current Injected Equivalent Circuit Approach (CIECA). The large-signal model based on state-space and switch model are also developed to verify the large-signal behavior. The simulation results of the proposed converter show that the output voltage of the proposed converter is successfully regulated to its desired value while the input current regulation is inherent.

A High-Efficiency Dimmable LED Driver for Low-Power Lighting Applications

This paper presents a dimmable light-emitting diode (LED) driver with adaptive feedback control for low-power lighting applications. An improved pulsewidth modulation dimming technique is studied for regulating the LED current and brightness. Under universal input voltage operation, high efficiency and high power factor can be achieved by a coupled inductor single-ended primary inductance converter power factor correction (PFC) converter with a simple commercial transition-mode PFC controller. The operation principles and design considerations of the studied LED driver are analyzed and discussed. A laboratory prototype is also designed and tested to verify the feasibility.

Fast-scale border collision bifurcation in SEPIC power factor pre-regulators

In this paper we report a kind of fast-scale instability occurring in the single-ended primary inductance converter (SEPIC) power factor pre-regulator, which is designed to operate in discontinuous conduction mode. Main results are given by exact cycle-by-cycle computer simulations as well as theoretical analysis. It is found that the instability phenomenon manifests itself as a fast-scale bifurcation at the switching period, which implies the occurrence of border collision bifurcation, or is related to the transition of the regular operating mode of the SEPIC. According to the theoretical analysis and simulation results, the effects of parameters on system stability, and the locations of the bifurcation points are confirmed. Moreover, the effects of such an instability on power factor and switching stress are also discussed. Finally, the occurrence of the asymmetric bifurcation locations is investigated. The results show that this work provides a convenient means of predicting stability boundaries which can facilitate the selection of the practical parameters.