Performance inspection of high gain chopper designed to extract optimum output of photovoltaic source

ABSTRACT


INTRODUCTION
The goal of creating a carbon-free nation by 2050 has been set by numerous nations around the world [1].The pressing need to achieve a sustainable, eco-friendly environment demands a substantial reduction in the usage of non-renewable fossil fuels such as coal, gas, and oil.Hence a worldwide concern has emerged to replace traditional fossil fuel-driven power generation with alternative energy sources that are not reliant on these depleting resources.One possible solution is to use renewable energy sources (RESs), like solar photovoltaic (PV) systems and fuel cells (FC) that are good for the environment, are connected to the utility grid, and have power electronics devices built in [2].Due to its numerous benefits, including ease of allocation, lack of noise, 2205 longer life, lack of pollution, quick installation, and output power capability to meet the highest load requirements, photovoltaic (PV) power generation has grown in importance as a renewable energy source [3].
In practical photovoltaic (PV) systems, the load level and external factors such as temperature and solar radiation undergo continuous fluctuations effectively regulate the operating point and sustain the system at maximum power point (MPP), the adoption of a suitable control algorithm and a high-performance DC-DC converter is imperative.With the help of MPPT controllers, power converters are mostly used to adjust the output voltage according to the needs of the application.The researcher has recommended numerous algorithms for maximum power point tracking (MPPT) operation for ease of use [4], [5].P&O, Incremental conductance (IC) algorithm are the most commonly used methods.The new strategy has gained popularity in recent years, and it is based on fuzzy logic control (FLC) [6].MPPT research also uses other artificial intelligence techniques.Additionally, MPPT converters using a soft switching technique are suggested to increase overall system efficiency [7].
The choice of a suitable photovoltaic (PV) converter is contingent upon several factors, including cost, adaptability, efficiency, and energy flow.Increasing the duty cycle in typical DC-DC step-up converters reduces stability and makes the control system more complex.The SEPIC, Cuk, and buck-boost converters are examples of well-known converters that can step up and down the source voltage.However, the insufficient output voltage adjustability makes boost and buck converters undesirable.When recommending DC-DC converters, a variety of aspects can be taken into account, including expense, flexibility, input/output flow of energy, and the impact of PV arrays.The SEPIC uses a back to back capacitor to separate input from output and has a non-inverted output [8].Owing to input switching, discontinuous input current results in increased power loss in the buck and buck-boost converters' performances.Although the boost converter typically outperforms the SEPIC in terms of efficiency, the voltage output is always greater than the input, making it difficult to extract the maximum amount of power.It is feasible for the output voltage to be higher or lower than the input voltage using Cuk and SEPIC converters [6], [8].
Several studies have been done on different converter schemes, which can be split into non-isolated and isolated configurations based on how they are coupled and used to get around the problems listed above [9]- [13].To use renewable energy, dual inductor-configured Switch Inductor (SI)-designed elevated lift-up converters are proposed [14].The utilization of linked inductors in existing topologies leads to low efficiency due to the high level of leakage in the inductance coils.In contrast, the proposed converter configurations are built upon a single inductor that can generate a high voltage gain (HVG) while simultaneously maintaining exceptional efficiency.Even if the majority of these designs achieve HVG, using a large component count raises the converters' operational cost and complexity.A feedforward boost converter based on SL-SC can achieve HVG with fewer components, however, it cannot exploit high efficiency [15]- [17].Few computational kinds of research have been proposed, and there are few studies on MPPT quadratic boost converters [18], [19].
In light of the aforementioned drawbacks, this article proposes a study and theoretical analysis of a high-gain chopper with a quadratic VDC and a P&O-based MPPT controller.Ultra-high gain is achieved using only a single switch and dual inductors, where VDC is combined with a quadratic structure.High-gain configurations suggested in [20]-[28] employ dual switches and have a significantly lower voltage gain than the converter provided in this study.The proposed configuration outperforms conventional PV and a battery source.Utilization of an MPPT controller did not deteriorate circuit permanence; rather, it can effectively transmit energy at all levels of radiation.
This paper is organized into five distinct sections, each with relevant subsections.Sections and 2 provide an extensive literature review and background of the research.Following this, section 3 presents an indepth analysis of the circuit's performance, while section 4 focuses on the results obtained from the experimentation and analysis.Finally, section 5 concludes the paper by summarizing the key finding and offering concluding remarks.

DESCRIPTION OF THE MPPT CONTROLLER
Numerous environmental factors, such as arbitrary shading, pollution, and wind issues, have an impact on PV power's sporadic functionality.Sunlight intensity varies significantly depending on the location and time of day; this causes variations in the solar cell's solar temperature and radiation.The design of the inverter next to the system is impacted by temperature and total resistance.The performance of photovoltaic (PV) power is subjected to wide range of environmental factors, such as shading, pollution, and wide-related issues, The intensity of sunlight varies significantly based on the location and time of day, leading to fluctuations in solar cell temperature and radiation.
Solar incorporated converters are used to raise the panel's voltage to its peak level and supply all of the effective power needed to extract the possible maximum power from the photovoltaic panel at any given time.The MPPT analyses the solar panel's supply current and voltage and chooses the operating point to supply the load with the most generated power.To increase PV efficiency, the MPPT must accurately follow the dynamic operating region where the wattage is at its peak.There are different ways to determine the PV's peak power.The complexity, speed, accuracy, affordability, and number of sensors needed for each of these systems vary.Among the above-mentioned MPPT algorithms, P&O provides significant benefits, and numerous research projects have adopted it.In P&O, the challenges are the fluctuation issue and tracing MPP in the rapidly changing climate.However, it is not impossible to identify the correct MPP during sudden climate changes [29].The process obtains its input from the solar PV array's actual operational point (current Ipv and voltage Vpv).Modifying the operating point (IPV, VPV), which is known as the perturbation step, and then evaluating the fluctuation in power (∆P), which is termed the observational step, are the two steps used to scan the P-V curve in order to get MPP. Figure 1 depicts the proposed circuit with an MPPT block, whereas Figure 2 displays the usual P&O system's flow diagram.

PROPOSED HIGH-PERFORMANCE CHOPPER
Figure 3 shows the suggested DC-DC converter structure.In the converter, there is only one switch (S), and it has two modes of operation displayed in Figures 4(a) and 4(b), respectively.The chopper circuit includes four capacitors, five diodes (D1, D2, D3, D4, and D5), and two inductors (L1 and L2).Components L1, L2, C1, D1, and D2 are performing a quadratic operation, whereas components C2, C4, D3, and D4 are operating as a voltage doubler.The capacitor Co also discharges, and the energy it had stored is used to power the load.Figure 5 displays some significant waveforms for the power converters for both switching intervals.

𝐷𝑇
(1) where D stands for the duty cycle.Similarly, the voltage across L2 can be written as under: For the switch ON condition, it can be written as (2).

𝐷𝑇
(2) Similar to (1) and (2) for the OFF condition, changes in the current for inductors 1 and 2 can be written as ( 3) and ( 4).
Applying KVL voltage across the capacitor is as (5).

Second operating mode (𝐷𝑇 𝑆 < 𝑡 < 𝑇 𝑆 )
The switch is not conducting at this time, causing the diodes D1, D3, and D5 to be conductive while the other two are non-conductive.The equivalent circuit is depicted in Figure 4(b).Consequently, L1 and L2 function as a series-connected circuit.The energy that is stored in L1 and L2 is used to provide load support through C2 and D5, as well as to charge C1 and C2 to transfer their energy.Applying KVL at the outer loop in Figure 4(b), potential difference across the inductor can be expressed as (8).
Where in the inner loop it can be written as (9).
The potential difference across the capacitor can be expressed as (10).

Derivation of voltage gain
For inductive voltage volt second balance over one switching cycle is zero.Utilizing ( 4) and ( 6) equation it can be written as (12).
Putting the value of VC1 in (12): Using a voltage doubler circuit, the final equation will be (14).

Equation of voltage stress on semiconductor components
Applying KVL, the voltage stress across the non-conducting element can be calculated.Hence the voltage between a switch and a diode, when they are not conducting, is given as (15).

Equitation of circuit parameters
Usually, the amount of ripple (between 5 and 10%) of the notional output current is taken into account to find the ideal size and loss for the converter.

Result analysis
To verify the theoretical findings, the design of the suggested converter circuit is developed and tested with MATLAB Simulink.The PV source used for simulation in MATLAB has a single parallel string and a single series-connected module per string.The values of the elements used for simulation are given in Table 1.Figures 6 show that the data used for simulation was a flawless convention for (a) PV source input and (b) converter output, producing the desired outcomes (Vout, Iout, and Pout) with a high level of efficiency.

2211
for 36 V input.It is evident from the zoom view of the signal that the proposed circuit's simulation waveforms follow the theoretical waveform.To ensure more acceptability of the recommended circuit, the proposed design has been utilized with a battery source too.However, the inclusion of a battery source provides a more precise output which is displayed in Figure 9 in terms of input output voltage and current.The high fluctuation presents in inductor current and PV voltage in existing topology compares to the proposed topology is visible in Figure 10 to Figure 12

Comparative Analysis
In this study, a comparative analysis of the suggested converter and other existing technologies is performed based on key indicators, such as the number of inductors, capacitors, diodes, and switches, as well as the effectiveness of maximum power tracking.The results demonstrate the proposed topology has a distinct advantage in efficiently tracking maximum power, while other configurations struggle to meet this requirement.This observation is depicted in Figure 13.Additionally, Figures 14(a

CONCLUSION
The present study details the design, development, and circuit analysis of a transformer less high stepup, non-isolated DC-DC chopper that is specifically tailored for solar photovoltaic (PV) systems.The proposed chopper is capable of achieving high gain using only a single switch and a quadratic cell-based VDC.At a duty ratio of 0.5, the voltage gain of the chopper is reported to be around eight times higher and even more at increased duty ratios when connected to a battery source, which is noticeably higher when compared to other converters.While incorporating a PV source, reduced fluctuation in current has been evaluated.Reduced voltage stress between capacitors influences the choice of low-power rating capacitors, increasing the converter's effectiveness (more than 90%) and reducing its cost.The proposed configuration is working efficiently for the PV and battery sources.Utilization of the P&O-based MPPT algorithm did not affect transformation efficiency; rather, other performance parameters improved significantly.Considering all these benefits, the proposed chopper can be implemented to step up the input voltage for applications requiring medium power.
Int J Pow Elec & Dri Syst ISSN: 2088-8694  Performance inspection of high gain chopper designed to extract optimum output … (Khadiza Akter)

Figure 1 .
Figure 1.Proposed topology configuration along with MPPT controller

10 )
Int J Pow Elec & Dri Syst ISSN: 2088-8694  Performance inspection of high gain chopper designed to extract optimum output … (Khadiza Akter) the capacitor's rated voltage output as a starting point, a capacitor voltage fluctuation value of [5-10%] is assumed.

Figure 6 .
Figure 6.Power, voltage, and current output of (a) PV source and (b) converter of the proposed design

Figure 7 .Figure 8 .Figure 9 .Figure 10 .Figure 11 .Figure 12 .
Figure 7. Waveshape of current carrying by diode (a) D1, (b) D2, (c) D3, and (d) D4 the proposed topology ) and 14(b) presents a comparison of the voltage gain and conversion efficiency of the suggested topology with other designs.The supremacy of the proposed design with battery source in terms of efficiency and gain is shown in Figures15(a) and 15(b) individually.Despite using fewer components than the suggested converter, the topology in [19] cannot achieve a significant voltage gain.A converter presented in [30] is exposed to extremely high voltage stress, including a poor voltage conversion ratio.The topologies suggested in[31], [32] can achieve a high gain in terms of voltage.Nevertheless, these topologies have required more components, and the switch is under severe voltage stress.In contrast to the suggested scheme, most topologies have reduced voltage gains and efficiencies for both PV and battery sources.

Table 1 .
Parameters value chosen for simulation

Table 1
Performance inspection of high gain chopper designed to extract optimum output … (KhadizaAkter)