A general approach to synthesis and analysis of quasi-resonant converters

A method for systematic synthesis of quasi-resonant (QR) topologies by addition of resonant elements to a parent pulse-width modulation (PWM) converter network is proposed. It is found that there are six QR classes with two resonant elements, including two novel classes. More complex QR converters can be generated by a recursive application of the synthesis method. Topological definitions of all known and novel QR classes follow directly from the synthesis method and topological properties of PWM parents. The synthesis of QR converters is augmented by a study of possible switch realizations and operating modes. In particular, it is demonstrated that a controllable rectifier can be used to accomplish the constant-frequency control in all QR classes. Links between the QR converters and the underlying PWM networks are extended to general DC and small-signal AC models in which the model of the PWM parent is explicitly exposed. Results of steady-state analyses of selected QR classes and operating modes include boundaries of operating regions, DC characteristics, a comparison of switching transitions and switch stresses, and a discussion of relevant design trade-offs

Bridgeless SEPIC Converter Based Computer Power Supply Using Coupled Inductor

Switched Mode Power Supplies (SMPS) are used as power source for computers. Conventional SMPS used in computers are suffered by some serious problems such as poor power quality, high device stress, slow dynamic response, high harmonic contents, periodically dense, peak currents, distorted input current. To minimize these problems, a non-isolated bridgeless buck-boost single ended primary inductance converter (SEPIC) using coupled inductor is introduced at the front end of the SMPS, which is operated in discontinuous conduction mode (DCM). This proposed technique reduces the Total Harmonic Distortion(THD), which results in power factor improvement. The DC output voltage of the SMPS is almost a constant voltage which is regulated by means of the proposed SEPIC converter. For obtaining different dc voltage levels for the PC applications, the output of the front end SEPIC converter is fed to the half-bridge DC-DC converter. The output voltages of the SMPS are controlled by controlling any one of the output voltages. Design and simulation of the proposed converter are carried out using the MATLAB/simulink software

Design, Analysis and Comparison of Si- and GaN-Based DC-DC Wide-Input-Voltage-Range Buck-Boost Converters

The purpose of the article is a comparison between DC/DC topologies with a wide input voltage range. The research also explains how the implementation of GaN E‑HEMT transistors influences the overall efficiency of the converter. The article presents a process of selection of the most efficient topology for stabilization of the battery storage voltage (9 V – 36 V) at the level of 24 V, which enables the usage of ultracapacitor energy storage in a wide range of applications, e.g., in automated electric vehicles. In order to choose the most suitable topology, simulation and laboratory research were conducted. The two most promising topologies were selected for verification in the experimental model. Each of the converters was constructed in two versions: with Si and with GaN E-HEMT transistors. The paper presents experimental research results that consist of precise power loss measurements and thermal analysis. The performance with an increased switching frequency of converters was also examined

Modified SEPIC Converter Performance for Grid-connected PV Systems under Various Conditions

Step-up converter is widely used to increase DC voltage level on PV systems either off-grid or grid connected. One of the step-up converters often used in PV systems is SEPIC converter. To improve its performance, many SEPIC converters have been modified. However, performance on various conditions has not been further investigated. In this study, the modified SEPIC converter was investigated under various change conditions for grid-connected PV applications. This converter was modelled and simulated using PSIM software. The modified SEPIC converter received input from PV array 15 kWp, and its output was connected to the three-phase inverter with grid and load. The irradiance level and ambient temperature were varied to test its performance and compared to Boost converter and SEPIC converter. For all tests, the performance of modified SEPIC converter was better than other step-up converters because it was able to rectify the quality of output voltage and more efficient

Design, Analysis and Comparison of Si- and GaN-Based DC-DC Wide-Input-Voltage-Range Buck-Boost Converters

The purpose of the article is a comparison between DC/DC topologies with a wide input voltage range. The research also explains how the implementation of GaN E‑HEMT transistors influences the overall efficiency of the converter. The article presents a process of selection of the most efficient topology for stabilization of the battery storage voltage (9 V – 36 V) at the level of 24 V, which enables the usage of ultracapacitor energy storage in a wide range of applications, e.g., in automated electric vehicles. In order to choose the most suitable topology, simulation and laboratory research were conducted. The two most promising topologies were selected for verification in the experimental model. Each of the converters was constructed in two versions: with Si and with GaN E-HEMT transistors. The paper presents experimental research results that consist of precise power loss measurements and thermal analysis. The performance with an increased switching frequency of converters was also examined

Survey on Photo-Voltaic Powered Interleaved Converter System

Renewable energy is the best solution to meet the growing demand for energy in the country. The solar energy is considered as the most promising energy by the researchers due to its abundant availability, eco-friendly nature, long lasting nature, wide range of application and above all it is a maintenance free system. The energy absorbed by the earth can satisfy 15000 times of today’s total energy demand and its hundred times more than that our conventional energy like coal and other fossil fuels. Though, there are overwhelming advantages in solar energy, It has few drawbacks as well such as its low conversion ratio, inconsistent supply of energy due to variation in the sun light, less efficiency due to ripples in the converter, time dependent and, above all, high capitation cost. These aforementioned flaws have been addressed by the researchers in order to extract maximum energy and attain hundred percentage benefits of this heavenly resource. So, this chapter presents a comprehensive investigation based on photo voltaic (PV) system requirements with the following constraints such as system efficiency, system gain, dynamic response, switching losses are investigated. The overview exhibits and identifies the requirements of a best PV power generation system

MPPT oscillations minimization in PV system by controlling non-linear dynamics in SEPIC DC-DC converter

Solar PV power generation has achieved rapid growth in developing countries which has many merits such as absence of noise, longer life, no pollution, less time for installation, and ease of grid interface. A maximum power point tracking circuit (MPPT) consists of DC-DC power electronics converters that are used to improve the energy attainment from solar PV array. This paper presents a detailed analysis to control of chaos, a non-linear dynamic in SEPIC DC-DC converter interfaced solar PV system, to minimize the oscillations near to MPP. In SEPIC DC-DC converter, the input inductor current is continuous and capable of sweeping the whole I-V curve of a PV module from open circuit voltage (Voc) to short circuit current (Isc) operating points. To trace the true maximum power point and to nullify the oscillations near to MPP, the yield output voltage needs to ensure period-1 operation

Simulation of TI-SEPIC Converter for BLDC Motor Drives

Power Factor Correction (PFC) is one of the research areas in the field of power electronics due to the enormous power required in various industrial applications. In this work, a SEPIC converter with the Tapped Inductor model which is operated in Discontinuous current Conduction Mode (TI-SEPIC- DCM) is proposed for a BLDC Drive. The proposed TI-SEPIC-DCM also improves the voltage gain with the help of voltage multiplier cell and charge pump circuit. It also helps in attaining the ZVS and ZCS, which results in higher switching frequency range and reduction in size reduction. Moreover, a third order harmonic reduction control loop is also proposed to attain a better third order harmonic elimination. The proposed work has been simulated using MATLAB simulink and the results are also validated