Boosted DC Research Articles

Multiple‐Input and Multiple‐Output–Based Cascaded Boost Hybrid Interlink Converter

ABSTRACTThe multiple‐input and multiple‐output (MIMO) DC–DC converters offer various advantages such as improved efficiency and reduced component count. However, the preference of these converters over other types of converters is dependent on the specific application and requirements. Various types of boost‐derived MIMO DC–DC converters are discussed in the literature. However, these converters are either nonisolated or isolated types. In the paper, a MIMO‐based cascaded boost hybrid interlink converter (CBHIC) has been proposed. The proposed converter includes four DC–DC boost converters that are supplied power by two input DC sources. The boosted DC output of these converters can be used independently or in a cascaded manner depending upon the requirement of the load. Further, the cascaded action of these four boost converters leads to the production of two high‐frequency AC outputs. By using bridge rectifiers and high‐frequency transformers, high‐frequency AC voltages are converted into DC. Therefore, two isolated DC output voltages can be achieved using CBHIC. The complementary operation of the cascaded boost converters results in reduction of source current ripples. The design, operating modes, and performance evaluation of the proposed CBHIC have been included in the paper. To validate the efficacy of the proposed CBHIC, a lab prototype of 400 W is prepared. The rms value of high‐frequency AC output voltage at each is isolated port is 141 V. The CBHIC exhibits an efficiency of 94.3 at 400 W. The operation of the converter during voltage control mode is further explored and its dynamic response is studies with the help of experimental results. The obtained simulation and experimental results validate the effectiveness of the proposed converter.

A boosted DC algorithm for non-differentiable DC components with non-monotone line search

A boosted DC algorithm for non-differentiable DC components with non-monotone line search

A Novel Nonisolated Four-Port Converter for Flexible DC Microgrid Operation

In this paper, a new non-isolated four-port DC-DC converter is proposed for DC Microgrid applications. The proposed converter offers a main feature of controlling the DC link voltage regardless of resources availability. By using four IGBT switches and only one diode, three different sources can be interfaced to a boosted DC link load. Different operation modes of the proposed architecture are discussed, testified and validated experimentally. The buck-boost capability of the proposed topology allows an enhanced flexibility to integrate various sources with distinct voltage-current (V-I) characteristics while sharing load power among all ports. In this context, steady state analysis is performed to determine the voltage gains between all ports. The control strategy is developed for the proposed topology to manage power flow between sources and load achieving basic operations for renewable resources such MPPT for PV. A theoretical based study is performed on the proposed converter including steady-state analysis, state-space averaging followed by small signal modeling and frequency response-based controller design. The converter different operating conditions are validated experimentally.

A Photovoltaic-Powered Modified Multiport Converter for an EV Charger with Bidirectional and Grid Connected Capability Assist PV2V, G2V, and V2G

To reduce the burden of electric vehicle (EV) charging power requirements, photovoltaic (PV) infrastructure EV charging has grown in recent years. The Z-Source Inverter (ZSI) allows tapping the boosted DC and AC by adjusting the switching shoot-through. However, it has only one DC tapping, thus limiting multiport charging options. This can be overcome by splitting the boosting capacitors used at the load terminal, which supports multiple charging ports, enabling simultaneous charging of multiple EVs, thereby increasing capacity and improving overall system efficiency. This paper presents a novel PV-tied Adaptable Z-Source Inverter (AZSI) for multiport EV charging. The modified split capacitor Z-source impedance networks ensure power availability at the charging station by regulating PV generation and grid supply. The performance of the AZSI was evaluated with experimentations that achieved an efficiency of 93.8% with three charging ports. This work contributes to developing sustainable and efficient charging infrastructure to meet the growing demands of the electric vehicle market.

Modelling and analysis of three-phase grid-tied photovoltaic systems

The global warming of the planet is as a result of human activities. Fossil fuel depletion and its high prices have caused a worldwide economic instability; governments around the world turn to alternative energy sources that are pollution-free. Solar photovoltaic system is one of the biggest renewable energy resources to generate electrical power and the fastest growing power generation in the world. The objectives of this work are: to ensure the maximum power point tracking (MPPT) in the side of the PV panels, to ensure the DC–DC boost converter boosts DC voltage by using the MPPT algorithm and pulse width modulation (PWM) technique, to invert the boosted DC voltage to three-phase AC voltages by using sine PWM technique to five-level VSI, to synchronize the PV-generated power to the grid power aided by the synchronous reference frame (SRF) controller. The step of modelling the photovoltaic system with MATLAB/Simulink was performed with RL-load and L-load and %THD got through FFT analysis. The results show that the DC voltage generated by the PVA produces an AC current sinusoidal at the output of the inverter. The contribution of the PV system to the grid consequently reduces the power fluctuation of the grid.

Power quality enhancement of grid-connected PV system

<span lang="EN-US">Solar photovoltaic (PV) power, for its multiple benefits, has adhered to prominent consideration in the electrical energy generation region. The double-stage triple-phase grid-connected solar PV (SPV) system is utilized to enhance the power quality by employing a lymphoblastoid cell lines LCL filter. In this method, a DC-DC converter and DC-AC converter make a feasible juncture of the PV systems to the electrical interface. For converting boosted DC into AC, A 3-phase DC-AC converter is used, which is supplied into the grid. A 3-phase voltage converter is employed in place of an inverter for interfacing amid the voltage generated by the PV system and the grid possessing an AC transmission line. An maximum power point tracking (MPPT) application is used in this proposal to amplify the effectiveness of the PV array in face of any unsteady climatic circumstances. Hence, the highest energy could be secured out of the solar PV array and interfaced with the grid. Enhancing power quality by employing an LCL filter is quantified by FFT analysis in MATLAB. The advised proposal has attained a very low total harmonic distortion (THD), proving its efficacy. Also, the outcomes ascertain the applications of the proposed system and extend future advances of renewable energy with a great power quality improvement.</span>

A New Multiport DC-DC Converter for DC Microgrid Applications

In this paper, a new multiport DC-DC converter is proposed for DC Microgrid applications. Besides, the proposed configuration has several benefits for the design and operation of DC microgrids such as reducing multiple power conversions, reducing number of elements and voltage boosting capability. The bidirectional buck-boost structure of the proposed topology allows for enhanced flexibility to connect sources and loads with different voltage and power levels. The control strategy is developed to achieve power control for renewable sources such as MPPT for PV, in addition to a certain degree of resilience for DC sources availability while maintaining boosted DC link voltage. The key feature of the proposed configuration is that it offers full control over DC link voltage regardless of resource availability (PV). A detailed steady-state analysis is conducted to derive the voltage relations between all ports. Additionally, the state-space averaging followed by small-signal modeling and frequency response-based controller design for the proposed topology is discussed. A MATLAB/Simulink-based simulation study is conducted to demonstrate the performance of the proposed multiport converter topology under different operating conditions. Finally, the performance of the proposed multiport converter is validated through an experimental study.

Efficient Boosted DC Algorithm for Nonconvex Image Restoration with Rician Noise

Image deblurring under Rician noise has attracted considerable attention in imaging science. Frequently appearing in medical imaging, Rician noise leads to an interesting nonconvex optimization problem, termed as the MAP-Rician model, which is based on the Maximum a Posteriori (MAP) estimation approach. As the MAP-Rician model is deeply rooted in Bayesian analysis, we want to understand its mathematical analysis carefully. Moreover, one needs to properly select a suitable algorithm for tackling this nonconvex problem to get the best performance. This paper investigates both issues. Indeed, we first present a theoretical result about the existence of a minimizer for the MAP-Rician model under mild conditions. Next, we aim to adopt an efficient boosted difference of convex functions algorithm (BDCA) to handle this challenging problem. Basically, BDCA combines the classical difference of convex functions algorithm (DCA) with a backtracking line search, which utilizes the point generated by DCA to define a search direction. In particular, we apply a smoothing scheme to handle the nonsmooth total variation (TV) regularization term in the discrete MAP-Rician model. Theoretically, using the Kurdyka--Lojasiewicz (KL) property, the convergence of the numerical algorithm can be guaranteed. We also prove that the sequence generated by the proposed algorithm converges to a stationary point with the objective function values decreasing monotonically. Numerical simulations are then reported to clearly illustrate that our BDCA approach outperforms some state-of-the-art methods for both medical and natural images in terms of image recovery capability and CPU-time cost.

MODEL BASED PREDICTIVE CONTROL STRATEGY FOR GRID-CONNECTED WIND ENERGY SYSTEM

In recent years, the move to green energy systems for power generation has greatly increased, and Wind Energy Systems (WES) are among the most efficient natural resources. Various control techniques can be employed to improve the amount of power generation and control the system's inverter. This paper implements a new Model Predictive Controller (MPC) for the Wind Energy Conversion System (WECS), which is connected to the grid. The system has wind energy as its input, and its AC source is converted into DC by a rectifier. A boost converter is injected for a constant and boosted DC output voltage from the rectifier, which is then converted to an AC supply by an inverter, controlled by MPC, and then connected to the grid. The proposed system is designed and simulated using the MATLAB tool. The results are verified, and the control technique is very efficient, enhancing system stability for the power generation in WECS. &nbsp

Double stage converter with low current stress for low to high voltage conversion in nanogrid

A low to high voltage conversion technique has been proposed in this paper using double stages of switched inductors for nanogrid applications. The proposed converter topology utilizes fewer components, achieves high voltage gain at a small value duty ratio, and has high efficiency. Moreover, the proposed converter provides a reduced switch current stress to obtain a stable constant boosted DC voltage. Therefore, it requires low-current rating switches and hence leads to cost reduction. Additionally, the load and the source end are connected to the same ground. The principle of operation, theoretical waveforms in Continuous Conduction Mode (CCM), and Discontinuous Conduction Mode (DCM) with steady-state analysis are discussed. A detailed discussion about the effect of non-idealities on the high voltage conversion, the design of components, and a comparison of the performance characteristics such as the number of components, Voltage Gain in CCM, switch current stress, normalized switch voltage stress, and efficiency of the proposed converter topology with other converters are presented. The experimental results of the 500W laboratory prototype are also shown to validate the operation of the proposed converter.

Experimental Testing of Low Power Consumption and Cost-effective Converter for De-icing System in Aircraft, Wind Turbine and Solar Panel with the Help of Induction Heating

This paper shows a topology about de-icing of aircraft wings and tails with the help of voltage fed high frequency parallel resonant inverter with the induction heating load. Icing of aircraft reduces the lift and trust of the aircraft. The aircraft de-icing system is economically expensive and consumes more power. To overcome the above factor the new proposed model is developed. It is based on the operation of the rectifier used in a circuit and Pulse Width Modulation technique. Bridgeless rectifiers used to convert the AC to boosted DC voltage without the help of choppers and parallel resonant converter proposed to do high frequency conversion help to reduce the losses in power. The characteristics are analysed by the simulation operation and practical results in terms of temperature, time, voltage and current. Analysis is carried out with the help of MATLAB and waveform is obtained. The prototype is built and tested the practical results to reduce the de-icing system. The icing melting point is 0?C and water to steam conversion melting point is achieved with 80C in our proposed converter and also practical tested in a pilot scale model.

FFNN BASED MPPT CONTROLLER FOR PEMFC POWERED NON-ISOLATED HIGH GAIN DC-DC CONVERTER WITH SPWM INVERTER FED BLDC MOTOR

A Non-Isolated High Gain DC-DC converter fed from 1.2kW PEMFC is designed to boost the fuel cell voltage. The Feed-forward Neural Network based MPPT controller algorithm is implemented to adjust the duty cycle of DC-DC converter in order make sure optimum power extraction from PEMFC whose result is compared with Fuzzy Logic Controller. The boosted DC voltage is inverteted to drive BLDC motor by three phase inverter. The inverter switches are triggered with switching pattern generated by SPWM technique according to the Hall sensor signals placed at stator of BLDC motor to find the position of rotor. The simulation anlysis has been carried out using MATLAB (R2017a)/Simulink platform and discussed the results.

Power Quality Improvement for Grid-connected PV System Based on Distribution Static Compensator with Fuzzy Logic Controller and UVT/ADALINE-based Least Mean Square Controller

This paper presents a novel method of power quality enrichment in a grid-connected photovoltaic (PV) system using a distribution static compensator (DSTATCOM). The paper consists of two-step control processes. In the primary step, a fuzzy logic controller (FLC) is employed in the DC-DC converter to extract the peak power point from the PV panel, where the FLC produces a switching signal for the DC-DC converter. In the secondary step, a unit vector template (UVT)/adaptive linear neuron (ADALINE)-based least mean square (LMS) controller is adopted in the DC-AC converter, i.e., voltage source converter (VSC). The input to this VSC is the boosted DC voltage, which originates from the PV panel as a result of DC-DC conversion. The VSC shunted with the power grid is known as a DSTATCOM, which can maintain the power quality in the distribution system. The UVT controller generates reference source currents from the grid voltages and DC-link voltages. The ADALINE-based LMS controller calculates the online weight according to the previous weights by the sensed load current. The UVT/ADALINE-based LMS controller of a DSTAT-COM performs several tasks such as maintaining the sinusoidal source current, achieving a unity power factor, and performing reactive power compensation. The reference current extracted from the UVT/ADALINE-based LMS controller is fed to the hysteresis current controller to obtain the desired switching signal for the VSC. A 100 kW solar PV system integrated into a three-phase four-wire distribution system through a four-leg VSC is designed in MATLAB/Simulink. The performances of the FLC and UVT/ADALINE-based LMS controllers are demonstrated under various irradiances as well as constant temperature and nonlinear loading conditions.

Using Positive Spanning Sets to Achieve d-Stationarity with the Boosted DC Algorithm

The Difference of Convex functions Algorithm (DCA) is widely used for minimizing the difference of two convex functions. A recently proposed accelerated version, termed BDCA for Boosted DC Algorithm, incorporates a line search step to achieve a larger decrease of the objective value at each iteration. Thanks to this step, BDCA usually converges much faster than DCA in practice. The solutions found by DCA are guaranteed to be critical points of the problem, but these may not be local minima. Although BDCA tends to improve the objective value of the solutions it finds, these are frequently just critical points as well. In this paper we combine BDCA with a simple Derivative-Free Optimization (DFO) algorithm to force the d-stationarity (lack of descent direction) at the point obtained. The potential of this approach is illustrated through some computational experiments on a Minimum-Sum-of-Squares clustering problem. Our numerical results demonstrate that the new method provides better solutions while still remains faster than DCA in the majority of test cases.

A Voltage-Boost Rectifier Circuit for Energy Harvesting from Environmental Vibrations

We propose a VBR (voltage-boost rectifier) circuit based on the 0.18-μm Si CMOS (complementary metal oxide semiconductor) technology, which is designed for vibrational energy harvesters utilizing environmental vibrations. The VBR employs a single-end Dickson type charge-pump topology, and the circuit would be realized as a monolithic chip. The evaluation results obtained by multi-physics simulations on a circuit simulator reveal that the proposed circuit can deliver boosted DC voltage from the input of sub-threshold AC voltage.

Improving the power quality of the wind power system using low cost topology

In this paper, Vienna rectifier (three-phase/three-switch converter) and Z-source inverter (ZSI) have been proposed with fewer number switches to enhance the power quality of off-grid wind power system (WPS). Conventional WPS used three-phase full-bridge converter for the AC/DC conversion and need separate DC–DC boost converter to increase the DC voltage. Compared to the conventional method, the proposed WPS uses three-phase/three-switch Vienna rectifier for AC/DC conversion and boosts the DC voltage. The boosted DC voltage is again boosted by ZSI to reduce the voltage sag and increase the quality of power of the off-grid system. The ZSI uses the shoot-through states to improve the DC link voltage and decrease the electromagnetic interference noise. The combination of Vienna rectifier and ZSI provides best quality performance which improves the efficiency and reduces cost and total harmonic distortion. MATLAB/Simulink software was used to simulate the proposed system. The feasibility of the proposed system is validated by simulation and prototype experimental results.

Improved Soft Start Capability of Induction Motor Using Solar Power Generation Based Z Source Inverter

This Paper present the photovoltaic power generation based Z Source inverter fed induction motor for enhanced soft start capability. The solar decentralization of power generation and increasing purpose of non-conventional energy sources has become requirement to assume a low cost power generating system for operating in remote areas. The Solar Power Generation System based Z Source inverter for feeding dynamic (induction motor drive) as well as static load is proposed and implemented for rural and remote areas. Hence, in this topology used to achieve better efficiency and reliability of the system while compared to conventional VSI type scheme. The solar cell model is formulated using basic single diode circuit equations of the photovoltaic cells admitting the effects of temperature changes and solar irradiation. Here, the Z- Source inverter is uses a unique impedance network coupled with inverter circuit and also used to realize the boosted DC to AC conversion. Induction motor has ability to self start outstanding to the interaction between the rotor winding flux and rotating magnetic field flux, inducing a high rotor current as torque is increased. In this paper proposed the design of soft starter fed induction motor by controlling the applied voltage. It is used to provide the low cost, size, better performance of startup machine, Controlled acceleration and improvement of efficiency. The corresponding simulation results have been verified using Matlab/Simulink Environment.

MODELING & ANALYSIS OF STANDALONE PHOTOVOLTAIC SYSTEM

This paper represents the three phase Photovoltaic system connected with variable load in a standalone mode’s mathematical modeling using MATLAB/ Simulink environment. The sy stem consist of a PV Array, Boost converter, three phase inverter and its control to maintain load in standalone mode. The 40 kW systems at the college site is under the study with a variable inductive load of 30kW which has to be fed by PV system in continuous mode .This paper gives analysis of each components of system while maintaining the load. The constant and boosted DC v oltage is obtained with the help of boost converter from PV Array. The three phase IGBT inverter PWM control scheme is proposed here to normalize the voltage imbalance during vari able load.