With the increase in the power demand and limited fossil fuels the renewable energy source plays a vital role to overcome these challenges. The fossil fuels based energy source causes environmental pollution. This led to the need for renewable energy sources (solar, wind, biomass) which is abundant and pollution free -. DC-DC converters play a vital role in photovoltaic (PV) systems as power interface. For stand-alone PV systems such as water pumps, LED, and signals, the MPPT technique is implemented -. InterleavedDC-DCconverter is a technique where it can be implemented by paralleling the converters such that it reduces the switching stress and peak inductor current compared to conventional boostconverter . The block diagram of proposed system is as shown in fig.1.
Abstract—System efficiency and cost effectiveness are of critical importance for photovoltaic (PV) systems. This paper addresses the two issues by developing a novel three-port DC-DCconverter for stand-alone PV systems, based on an improved Flyback-Forward topology. It provides a compact single-unit solution with a combined feature of optimized maximum power point tracking (MPPT), high step-up ratio, galvanic isolation and multiple operating modes for domestic and aerospace applications. A theoretical analysis is conducted to analyze the operating modes followed by simulation and experimental work. The paper is focused on a comprehensive modulation strategy utilizing both PWM and phase-shifted control that satisfies the requirement of PV power systems to achieve MPPT and output voltage regulation. A 250 W converter was designed and prototyped to provide experimental verification in term of system integration and high conversion efficiency.
critical importance for photovoltaic (PV) systems. This paper addresses the two issues by developing a novel three-port DC-DCconverter for stand-alone PV systems, based on an improved Flyback-Forward topology. It provides a compact single-unit solution with a combined feature of optimized maximum power point tracking (MPPT), high step-up ratio, galvanic isolation and multiple operating modes for domestic and aerospace applications. A theoretical analysis is conducted to analyze the operating modes followed by simulation and experimental work. The paper is focused on a comprehensive modulation strategy utilizing both PWM and phase-shifted control that satisfies the requirement of PV power systems to achieve MPPT and output voltage regulation. A 250 W converter was designed and prototyped to provide experimental verification in term of system integration and high conversion efficiency.
The renewable energy resources are becoming a boon to the developing world where the necessity of electrical energy is increasing day by day. There are many types of renewable energy resources among them the solar energy is the superlative. Though photovoltaic (PV) cell has some limitations of high capitation cost, lower conversion efficiency, partial shading and seasonal energy production, it has seized the attention of many researchers because of its special virtues. The special virtues include costless source and maintenance free system. These systems are also pollution free that is environmental contamination is reduced to the minimum of zero percentage.
ABSTRACT: Interleavedboostconverter is a good interface between four different source and inverter. This Work deals with design, modelling and simulation of the interleavedboostconverter inverter based PID controlled four different source systems. Interleavedboost converters to reduce the ripple in the DC output. The DC from the solar cell is stepped up usinginterleavedboostconverter. The output of the interleavedboostconverter is converted to 50Hz AC using a single phase full bridge inverter. The objective of this work is to improve dynamic response of closed loop system using PID controller. The simulation results of PI and PID controlled closed loop systems are compared. This paper has presented a simulink model for the closed loop controlled four different source systems.
The main purpose of this paper is to establish a model for the grid-connected photovoltaic system with maximum power point tracking function for residential application. A single phase two-stage grid-connected photovoltaic inverter with a combination of SPWM and square-wave switching strategy is designed using MATLAB. In the proposed design, an MPPT algorithm using a boostconverter is designed to operate using (P&O) method to control the PWM signals of the boostconverter, which is adapted to the maximum power tracking in our PV system. Instead of using line frequency transformer at the inverter output terminals, a DC-DCboostconverter is used between solarpanel and inverter that efficiently amplify the 24V PV arrays output into 312V DC, which is then transformed into line frequency (50Hz) sinusoidal ac 220V rms voltage by the inverter and thereby reducing the system losses and ensures high voltage gain and higher efficiency output. The simulation results show that the proposed grid connected photovoltaic inverter trace the maximum point of solar cell array power and then converts it to a high quality ripple free sinusoidal ac power with a voltage THD below 8%. The simulation also confirms the proposed photovoltaic inverter can be applied as a GTI and able to supplies the AC power to utility grid line.
The Field Programmable Gate Array FPGA controlled solar photo voltaic (SPV) system is proposed in this paper. The Bi-Directional DC-DCConverter BDC is proposed for charging the battery during day hours and discharging of battery during night hours by operating in buck and boost modes respectively. For buck mode PID controller is preferred and TYPE 3 controller for boost mode of operation of BDC and implemented on FPGA. Besides the BDC, the maximum power point tracking MPPT charge controller is also designed with constant voltage maximum power point tracking CVMPPT and used in FPGA after conversion in digital domain form.
The solarpanel provides the necessary input voltage for the converter to operate. The pic microcontroller is interfaced with mppt using fuzzy logic. The controller circuit will help the driver circuit for turning on and off of the mosfet switches in the interleavedboostconverter. this helps the working of the converter as mentioned in the operation of the converter. The two stage voltage multiplier circuit will further help in the boosting of the output voltage. The filter circuits help in removing the harmonics and in reducing the ripple voltage and current values. The load side consists of a battery as in this case which will be charged by the help of the step upped voltage from the solarpanel. The circuit is made not only to boost the voltage but also it will be used faster charging of the battery than conventional boost converters for better utilization of the available power.
Nowadays, the renewable-energy grid-connected systems with photovoltaic (PV) and fuel cells call for high step-up and high-current DC-DC topologies, because of the low voltage generated by the PV panel and fuel cells should be boosted to a relatively high dc bus voltage for the grid-connected generation systems. For example, in order to deliver the energy to a single-phase 220V utility grid, a 380V DC bus voltage is required with a full-bridge inverter. Unfortunately, the output voltage of most fuel cell stacks or the individual PV cells is lower than 40V due to the safety and reliability issues in the household applications. Large voltage conversion ratio with over ten times of voltage gain is necessary for the front-end DC-DC converters. As a result, non-isolated high-step-up converters are desirable to reduce the system cost and to improve the power density by removing the isolated voltage or current sensors and additional auxiliary power supply in the isolated conversion systems. The converter having an interleaved inductor achieves extremely large voltage conversion ratio with appropriate duty cycle and reduction in voltage stress on the power devices. The leakage inductance energy can be efficiently discharged by using coupled inductor. Since, the device stresses are low in this topology, low voltage MOSFETs with small values of R DS (on) can be selected to reduce
ABSTRACT : This paper presents the comparative study of DC-DC converters employed for standalone solar powered panel for single-phase supply. Presently, MNRE (Ministry of New and Renewable Energy) India, is compulsorily reducing the carbon footprint generated by production of electricity by incorporating the photovoltaic panel at every level. Increased demand of photovoltaic panel and its accessories needs to be efficient and must be eco- nomical. As in standalone system, the photovoltaic panel is preceded by DC-DCconverter and then in series with DC-AC converter. In this paper DC- DCconverter is discussed with the modeling and simulation of Traditional BoostConverter (TBC), Swithced Inductor BoostConverter (SIBC) and Coupled Inductor BoostConverter (CIBC) with rated power supply for single-phase inverter. In many cases, roof top supply system has become popular for domestic supply but still partial shading, design element, rating of component according to power requirement is a big issue. TBC, SIBC, and CIBC are discussed mathematically and graphically and then simulated in MATLAB.
The output power generated from the PV panel is varying under certain environmental conditions such as temperature, irradiation, shading etc, hence PV system has low conversion efficiency [9,10]. Therefore a good MPPT is required to ensure the maximum available power from the solarpanel. The output power of the PV module is directly proportion to the solar irradiation and inversely proportional to the ambient temperature. For better PV utilization it must be operated at equilibrium point. This point is commonly known as Maximum Power Point (MPP) or peak power voltage. MPPT technique can be used in both standalone and grid connected PV system. The general block diagram of MPPT technique is as shown in Fig.4. normally it consists of a PV array, DC-DCconverter for boosts the output voltage generated from PV array and a MPPT controller .
A block diagram of series connected converters is shown in Figure 2.6. This configuration is used in low power wind generator and solarpanel applications (Chan, 2002, 2007; Chan et al. , 1993). In this circuit configuration, output voltage and current regulation are difficult to be controlled since both tile sources used could have intermittent character (Chan & Chau, 1997; Marwali et al. , 2000; Glavin & Hurley, 2006). The main drawbacks of such systems are that output current flows through both converters and therefore power loss is high (Hirachi et al. , 1995; Sopitpan et al. , 2000). Furthermore, gating signals for both input voltage sources are conjunctive which might create a circulating current in tile two input sources.
Nowadays when fossils fuel is degrading continuously, renewable energy is playing an important role in facing the continuous demand for electricity without damaging the environment. Generally, solar panels are widely used for producing electrical energy as it does not create any harm to the environment. The output of these panels is variable, therefore to achieve a constant output, Buck-Boost converters are used. DC-DC converters are important topology which can improve the performance of renewable energy sources . DC-DC converters are used to change voltage levels of DC source from one level to other. These converters can both step-up or step-down the initial voltage . In higher power rating inductor of Buck-Boostconverter become bulkier. This inductor causes an increment in voltage and current ripple of the converter. In addition, most of the DC-DC converters have drawback of pulsating input and output current which creates high noise and makes control of system complicated due to current limitations . To avoid these ripple and drawbacks without compromising power rating of the system an Interleaved Buck-BoostConverter can be used. In Interleaved Buck-BoostConverter inductors are placed in the parallel configuration so net inductance gets reduced. As
The rise in the price of oil and pollution issues has increased the interest on the development of electric vehicles. This paper discusses about the application of solar energy to power up the ve- hicle. The basic principle of solar based electric vehicle is to use energy that is stored in a battery to drive the motor and it moves the vehicle in forward or reverse direction. The Photo Voltaic (PV) module may be connected either in parallel or series, and the charge controllers direct this solar power to the batteries. The DC voltage from the PV panel is then boosted up using a boostDC-DCconverter, and then an inverter, where DC power is converted to AC power, ultimately runs the Brushless DC motor which is used as the drive motor for the vehicle application. This paper focus- es on the design, simulation and implementation of the various components, namely: solarpanel, charge controller, battery, DC-DCboostconverter, DC-AC power converter (inverter circuit) and BLDC motor for the vehicle application. All these components are modeled in MATLAB/SIMULINK and in real-time, the hardware integration of the system is developed and tested to verify the si- mulation results.
The output of PV module is dependent on temperature and solar irradiation values. With the change of solar irradiation and temperature P-V and I-V curves of solar cell changes accordingly giving variation in output curve but control mechanism like algorithms of P &O and IC methods including iterative processes can track this change and can extract maximum power available in the PV cell. In this way it caters to the need of the load demand .Higher value of solar irradiation results in increased power curve.Variation in the solar irradiation results in the variation of open circuit voltage.The open circuit voltage increases with the increase of solar irradiation.This happens when more packets of photons are incidented on the panel,thereby supplying the electrons with higher excitation energy,which increases the electron mobility and so large power generated.
The figure 4.1 shows the three phase voltage source inverter. The full bridge three phase inverter consists of dc voltage source, six semiconducting switches and a load. The semiconducting switching nowadays are BJT, IGBT, Thyristor and GTO . The diodes provide as an alternate path for the load current if the power switches are turned off. Control of the circuit is accomplished by varying the turn on time of the upper and lower MOSFET of each inverter leg with the provision of never turning ON both at the same time, to avoid a short circuit of DC bus . The control pulse to the swatches may be generated by either microcontroller or DSP. A variable voltage can be obtained by varying the input dc voltage and maintaining the gain of the inverter constant. On the other hand, if the dc input voltage is fixed then variable output voltage can be obtained by varying the gain of the inverter. This can be accomplished by pulse width modulation (PWM) technique within the inverter. PWM means the width of the square pulse in positive and negative halves can be adjusted according to the RMS of the output obtained. The inverter gain is defined as ratio of ac output voltage to the dc input voltage. Here, the input to the inverter is supplied from the boostconverter and expected output voltage is 210 V.
Germany. Since Jan 2013, 1,024 Mega-solar plants is planned total capacity of Mega-solar will be 5.750[GW]. This amount of capacity is equal to 6 nuclear power generation plants with total investment about 1,500 billion yen excluding land price. For this reason, many electronic and investment companies interests on Mega-Solar business. One of the problem of interconnection was stated that some Japanese electric companies have declared that many investors and contractors are rushing to contract selling their renewable energy power to the utilities. However, they can only purchase ¼ of the electricity from Mega-Solar because interconnection limitation. As a result, when huge amount of power the reactive power of main grid is consumed and the voltages raised at the connected bus and frequency of the main grid dropped. PV system should be controlled in two ways: First using MPPT control system to control the different outputs of PV to reach and track the maximum power. Second, control DC/AC Inverter to control voltage, current and active power then connect PV to nearest utility grid. In this paper, we consider on two case study;
ABSTRACT: This paper proposes a soft switching converter with high voltage gain for ac and dc photovoltaic applications. Day to day energy usage is snowballing significantly. Dc-Dc converters are the major consequence in renewable grid connected power applications because of the low voltage PV arrays. This shortcoming is overcome by using a novel soft switching dc-dcconverter. This proposed concept is used to change the power efficiency by boosting voltage and also reduces the switching losses and efficiency. This problem is handled by using a high gain interleaveddcboostconverter with capacitor and leakage inductor. A passive clamp network round the inductors affords the recapture of energy through leakage inductance leading to upgrading in the voltage gain and efficiency. The benefit of passive clamp network is that it condenses voltage stress on the switch. This proposed converter is designed and implemented by MATLAB/Simulation software and the results are results are validated.
The high voltage gain is obtained when the converter is operating for duty cycle greater than 50% (K > 0.5), the analysis of the converter is also presented for duty cycle less than 50% (K < 0.5). The power losses are neglected for analysis. Since both converters are boost type, the voltage across each capacitor is greater than the input voltage. Assume that converter is operated in continuous conduction mode (CCM) and the two converters have same duty ratio.