Description:FIELD OF THE INVENTION
This invention relates to for Microgrid Advanced Modified Voltage Multiplier DC-DC Circuit Systems
BACKGROUND OF THE INVENTION
At present, the world is facing a crucial rise in energy demand, due to rapid industrialization, urbanization towards sustainable energy. To overcome the above issue, fuel cells came as a solution to address this demand because of their ability to convert energy efficiently and cleanly. However, there are several mitigations in implementation of fuel cells as it produces low voltage output, which is not sufficient for practical applications like electrical vehicles, renewable energy system, and portable devices. To overcome this limitation, effectual power conversion is required to set up the voltage high. This paper mainly focuses on non-isolated DC-DC converter that provides high-voltage conversion ratio, used for fuel cells applications. This converter plays a crucial role in converting low voltage to high voltage efficiently to different types of loads with low energy losses. Here converter uses multi-phase interleaving and duty cycle modulation techniques to get high voltage gain. This features not only improve efficiency but also reduce the voltage ripple and improve the overall system stability. It also offers several advantages, such as improved efficiency, reduced thermal stress, fewer components, and better voltage regulation. For accurate performance simulation tools like MATLAB/Simulink and PSIM are used. This Simulink results that the proposed converter achieves high voltage conversion ratio while minimizing energy loss. In conclusion, the high-voltage non-isolated DC-DC converter presented in this paper offers a reliable, energy-efficient, and reasonable solution for fuel cell applications, making it well-suited for renewable energy systems and electric vehicles.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention.
This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
The DC-DC converter's directly coupled structure appears in Figure (1). The configuration centers around one switching semiconductor that enables large voltage gain while minimizing the duty cycle to its lowest point. Four inductors named Lx, Ly, Lz and Lu together with five diodes labeled Dx, Dy, Dz, Du, and Dv and six capacitors identified as Cx, Cy, Cz, Cu, Cv, and Cw and a single semiconductor switch designated Q1 composes the circuit structure. The proposed converter uses several different components to increase voltage but demonstrates outstanding power efficiency rates. The analysis focuses on perfect components while assuming large capacitors that remove all harmonic voltages to calculate equilibrium voltage improvements.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated embodiments of the subject matter will be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
FIGURE 1: SYSTEM ARCHITECTURE
The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
In addition, the descriptions of "first", "second", “third”, and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The DC-DC converter's directly coupled structure appears in Figure (1). The configuration centers around one switching semiconductor that enables large voltage gain while minimizing the duty cycle to its lowest point. Four inductors named Lx, Ly, Lz and Lu together with five diodes labeled Dx, Dy, Dz, Du, and Dv and six capacitors identified as Cx, Cy, Cz, Cu, Cv, and Cw and a single semiconductor switch designated Q1 composes the circuit structure. The proposed converter uses several different components to increase voltage but demonstrates outstanding power efficiency rates. The analysis focuses on perfect components while assuming large capacitors that remove all harmonic voltages to calculate equilibrium voltage improvements.
CCM (Continuous Conduction Mode):
In power electronic arrangements Continuous Conduction Mode operates as a technique that maintains reactor current flow above zero throughout each switching cycle. Industrial DC-DC converters use this operational mode to improve current flow quality while protecting critical components against extensive stress.CCM utilizes two main divergent methods referred to as Method-A and Method-B. The current flow patterns in both techniques appear in Fig 2. The methods employ contrasting techniques for transforming the current flow yet they support continuous conduction to enhance system performance and efficiency.
Method-A Operation:
The method starts with Q1 activation causing Dx to become reversed-biased while Fig 2 shows all the inductors coming into operation. The inductor Lx operates from input Voltage Vi and Ly functions with capacitor voltage VCx while Lz receives power through diode Dy to support power from VCy and VCu. The standard power supply operates on Capacitors Cz and Cv, yet Cw provides current to the load through its discharge process. The voltage relationships appear as follows:
(1)
Method-B Operation :
When Q1 (switch) enters its inactive state both Cx and Cy receive energy from the stored inductors Lx and Ly while receiving Vi voltage over Dx and Dz. The device consisting of Lz provides power to Cu through Du acting as the conducting element. The stored charge from Cz, Cv and Lu passes through diode Dv to excite Cw until it creates a supply flow for the attached load. The description of voltage connections in these systems shows the following relationships:
(2)
By using volt-second balance principle, the following equations are obtained
(3)
(4)
The values Vcx, Vcy, Vcu, Vcz and Vcv stem from the input voltage (Vi) in combination with the duty cycle δ. The anticipated configuration has the following value for its voltage conversion ratio (M):
(5)
The conversion ratio M demonstrates the relationship that exists between output voltage Vo and input voltage Vi. The symbolic waveforms show the elements' energizing and depleting operation for the anticipated converter in both Method A and Method B.
DCM (Discontinuous Conduction mode):
Three distinct operational methods run in this mode. The operating principle of Method A and Method B functions identically to CCM systems. The circuit operates like CCM during the first interval (TO < T < T1) because uninterrupted current flows through its components without interruption. The currents flowing through diodes Dx, Dz, Du, and Dv decline while the system moves from the first interval range (TO < T < T1) to the second interval range (T1 < T < T2). A decreasing current rate shows that the system moves away from maintaining uninterrupted current flow. The third interval (T2 < T < T3) leads to the elimination of currents through diodes as well as potential differences across inductors Lx, Ly, Lz and Lu. When the diodes develop a reverse-biased state they stop conducting electricity and switch off. The stored energy inside the circuit passes through to the output capacitor (Cf) which maintains a constant power supply for the load.
The equation obtained during the second interval is as follows:
(6)
The mean current passing over diodes Dx, Dz, Du and Dv is given below:
(7)
From the symbolic waveform, the average currents of the diodes Dx, Dz, Du and Dv are as follows:
(8)
δm2 is the duty factor in the subsequent (2nd) interval.
(9)
By solving equations (7) and (9), the duty cycle δm2 is
(10)
Based on volt-second principle applied to the inductors Lx, Ly, Lz and Lu in DCM operation, the duty cycle δm2 and voltage gain GDCM are given as follows:
(11)
(12)
Equations (10) and (12) can be used to get the voltage transfer gain, which is
(13)
Where the stabilized inductor time constant is denoted by KL:
¬¬ (14)
This mode is useful for operations requiring renewable energy and regulated power distribution. While DCM allows for an asymmetrical gearbox and has fewer losses compared to CCM, which maintains a continuous current throughout the switching cycle, careful design considerations are still essential to guarantee stability and efficiency.
BCM (Boundary Conduction Mode)
The power electronics functioning model uses a mechanism called BCM (Boundary Conduction Mode) to link between steady-state and Non-Continuous Conduction Mode. At the start of every new switching period after current reaches zero BCM quickly initiates inductor current rise to prevent the extended zero-current duration of DCM.
The calculation of Kb requires matching the voltage gain from GCCM with GDCM using equations (11) and (13).
(15)
During steady-state operation the parameter KL surpasses the threshold Kb which maintains inductor current flow without interruption at any time in the switching cycle. When the converter operates above the threshold Kb it becomes more efficient due to decreased losses and steady energy transfer. Increased switching losses accompany this operating mode although it proves advantageous for load conditions which help decrease circuit component stress.
 
, Claims:1. An Advanced Modified Voltage Multiplier DC-DC Converter, comprising: a single semiconductor switch, inductors, diodes, capacitors and a directly coupled topology.
2. The system as claimed as claim 1, wherein the topology enables a step-up voltage conversion with reduced switching stress and improved efficiency, without relying on extreme duty cycles.
3. The system as claimed as claim 1, wherein the capacitors (Cx, Cy, Cz, Cu, Cv, Cw), each having sufficiently large capacitance to suppress output voltage ripple.
4. The system as claimed as claim 1, wherein the diodes (Dx, Dy, Dz, Du, Dv) connected to direct current flow during switching cycles.
5. The system as claimed as claim 1, wherein the inductors (Lx, Ly, Lz, Lu) arranged to facilitate magnetic energy storage and transfer.
6. The system as claimed as claim 1, wherein the single semiconductor switch (Q1) configured to operate at a low duty cycle.
7. The system as claimed as claim 1, wherein the directly coupled topology connecting said inductors, diodes, and capacitors such that energy is transferred from a low-voltage input to a high-voltage output.