Download PDF Article Open access Published: 29 May 2025 Neutral point clamped inverter for enhanced grid connected PV system performance based on hexagonal space vector modulation R.

Palanisamy1, K. Vijayakumar1, Mohammad Imtiyaz Gulbarga2, Mohammed Al Awadh3,4 & …Liew Tze Hui5 Show authors Scientific Reports volume 15, Article number: 18881 (2025) Cite this article

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costs. Despite these advantages, challenges such as high total harmonic distortion (THD), common mode voltage (CMV) issues, and neutral current imbalance must be addressed to ensure reliable

grid integration. This research investigates a transformerless five-level neutral point clamped (NPC) inverter for grid-connected PV applications, aiming to overcome these challenges. The

study focuses on analysing THD, mitigating CMV to enhance system reliability, and optimizing output voltage levels to meet grid standards. The proposed transformerless five-level NPC

inverter, incorporating a coupled inductor, is controlled using Hexagonal Space Vector Modulation (HSVM) to improve performance. Additionally, the research evaluates neutral current behavior

to ensure stability and compliance with grid codes. Simulation and experimental results validate the proposed system’s effectiveness under varying operating conditions, highlighting its

potential as a high-efficiency, cost-effective solution for sustainable energy integration into the grid.

transformerless photo voltaic inverter Article Open access 26 March 2025 Implementation of adaptive hysteresis current controller in grid tied multilevel converter with battery storage

system Article Open access 23 May 2025 Low cost and compact six switch seven level grid tied transformerless PV inverter Article Open access 14 March 2025 Introduction

Photovoltaic (PV) systems have emerged as a reliable and sustainable energy source, addressing the growing global demand for clean electricity1. With advancements in PV technology,

grid-connected PV systems are now widely deployed in residential, commercial, and industrial applications2. Efficient inverters are necessary for PV system integration with the power grid to

transform the DC output from PV panels into AC voltage that is compatible with the grid3. Transformerless inverters are becoming more and more popular among different inverter topologies

because of their lower cost, weight, and size as well as their higher overall efficiency4,5,6.

In a grid-connected PV system, the inverter plays a critical role in ensuring high energy conversion efficiency while meeting stringent grid standards for power quality and safety7. In this

context, the five-level Neutral Point Clamped (NPC) inverter is a desirable architecture because it provides low switching loss, lower THD, and greater voltage levels than conventional

two-level or three-level inverters. Moreover, the transformerless configuration eliminates the bulky transformer, further improving efficiency and cost-effectiveness, while requiring careful

management of leakage currents and common-mode voltage to ensure safety and reliability8. Its importance can be highlighted as follows: most electrical grids and household appliances

operate on AC. The inverter ensures that the DC output from PV panels is efficiently transformed into usable AC power. For grid-connected systems, the inverter synchronizes the output

voltage, frequency, and phase with the grid, ensuring seamless integration. Modern inverters minimize Total Harmonic Distortion (THD) and provide high-quality AC output, improving system

efficiency and reliability9. Advanced inverters optimize the power extraction from PV panels by continuously adjusting to the panels’ maximum power point under varying conditions10,11,12.

Multilevel inverters (MLIs) are an essential advancement in power electronics, particularly for applications involving renewable energy integration, industrial drives, and high-voltage

systems. Their unique ability to synthesize high-quality voltage waveforms with multiple voltage levels offers several advantages over conventional two-level inverters13,14,15. The

importance of multilevel inverters includes: MLIs produce output waveforms that closely approximate sinusoidal AC, significantly reducing THD. This improves power quality, minimizing the

need for large filter components and reducing electromagnetic interference16. By operating at lower voltage steps, MLIs minimize switching losses compared to two-level inverters, leading to

higher overall system efficiency. MLIs can handle higher voltage levels without requiring high-voltage-rated semiconductor devices17. This makes them appropriate for high-power usages like

grid-tied renewable energy systems, industrial motor drives, and electric vehicles. The stepped output waveform of MLIs reduces voltage stress on power electronic devices, increasing their

lifespan and reliability. Multilevel inverters can be configured in numerous topologies, such as NPC method, CHB method, and Flying Capacitor. This modularity allows designers to choose the

most suitable configuration for specific applications. The smoother voltage transitions in MLIs help in reducing electromagnetic interference, enhancing the electromagnetic compatibility of

the system18. MLIs are ideal for interfacing renewable energy sources like solar PV and wind turbines with the grid due to their ability to handle variable DC input and produce high-quality

AC output. MLIs facilitate better synchronization with the grid by providing high-quality output voltage, meeting stringent grid codes for harmonic limits and power factor19.

Since they establish the switching states of power semiconductor devices to construct the required output voltage and current, pulse width modulation (PWM) techniques are crucial for

regulating inverters20. Several PWM techniques have been created for multilevel inverters to enhance performance indicators such power quality, efficiency, and total harmonic distortion

(THD). SPWM has a limited modulation index and increased switching losses at low frequencies because it generates switching signals by comparing a sinusoidal reference signal with one or

more triangular carrier waves21. LSPWM is a specific form of SPWM used in multilevel inverters, where multiple triangular carrier waves are shifted in levels corresponding to the number of

voltage steps, here demerit is imbalanced capacitor voltages in certain topologies22. In Phase-Shifted PWM, the triangular carriers for each leg are phase-shifted relative to each other;

implementation is complex in higher-level inverters23. In Selective Harmonic Elimination, calculating specific switching angles to eliminate selected harmonic components24-25. By

synthesizing the reference voltage vector from the inverter’s discrete switching states, the conventional SVM employs the idea of space vectors to control the inverter. It has several

advantages, including a higher modulation index, better DC-link voltage utilization, and a lower THD.

Schematic diagram of proposed research work.

This article deals with investigation of Hexagonal SVM Transformerless five-level NPCI for grid connected PV system, which provides reduced THD of the output waveform, mitigating Common Mode

Voltage (CMV) to enhance reliability, and optimizing output voltage levels to meet grid standards. Various PWM methods are utilized in multilevel inverters, each with its unique benefits

and trade-offs. Among these, Space Vector Modulation (SVM) stands out as a versatile and efficient technique, offering superior DC-link voltage utilization, low THD, and reduced switching

losses. Its advantages make SVM particularly suitable for transformerless five-level Neutral Point Clamped (NPC) inverters, ensuring high-performance and reliable operation in grid-connected

PV systems. The Schematic diagram of proposed research work is shown in Fig. 1.

Using solar panels to transfers sunlight into direct current (DC) electricity, a photovoltaic (PV) system uses the sun’s energy to establish electricity26. Multiple solar cells composed of

semiconductor materials, such as silicon, that display the photovoltaic effect make up each panel. The cells produce an electric current in response to the incident solar irradiation when

they are exposed to sunlight. PV systems are modular, scalable, and environmentally friendly, making them a key component of renewable energy solutions. They can be deployed in standalone

configurations for off-grid applications or integrated with the electrical grid to support large-scale power generation.

A PV system’s performance is influenced by a number of variables, such as temperature, shading, solar irradiation, and the electrical load that is connected to the system. For optimal energy

generation, PV systems are typically paired with power electronics such as DC-DC converters and inverters to regulate voltage, current, and power output. In grid-connected systems, the

inverter plays a crucial role in synchronizing the PV-generated power with the grid. Accurate modelling of PV systems is essential to predict their behaviour under varying environmental

conditions and to design efficient power management strategies. The equivalent PV system and I-V characteristics of PV panel is shown in Fig. 2.

Based on fuzzy logic An intelligent and flexible method called Maximum Power Point Tracking (MPPT) is intended to maximize a photovoltaic system’s power output in the face of changing

climatic conditions.

$$\:{\text{I}}_{\text{d}}={\text{I}}_{0}({\text{e}}^{\text{q}{\text{v}}_{\text{d}}/\text{k}\text{T}}-1)$$ (2) Fig. 2

PV structure a) equivalent circuit b) IV characteristics.

a) P-Vi characteristics of cell b) Fuzzy based MPPT with varying irradiance.

Fuzzy logic MPPT does not necessitate a comprehensive mathematical model of the PV array, in contrast to standard MPPT procedures like Perturb and Observe (P&O) or Incremental Conductance.

Instead, it makes judgments based on the relationship between input variables, including the change in voltage (ΔV) and power (ΔP), using a rule-based system. The algorithm makes sure that

the PV system runs at its maximum power point even in the face of rapidly fluctuating temperature or irradiance by continuously modifying the duty cycle of the DC-DC converter. Fuzzy logic

MPPT’s resilience and capacity to manage the nonlinear properties of PV systems are two of its many noteworthy benefits. It can swiftly and oscillation-free converge to the maximum power

point in situations including partial shading. The fuzzy logic controller consists of three stages: fuzzification, where input variables are converted into fuzzy sets; inference, where

decision rules are applied; and defuzzification, where the output is converted into a crisp control signal. This method is ideal for contemporary renewable energy applications since it not

only increases the PV system’s efficiency but also guarantees steady and dependable operation. Figure 3 displays the photovoltaic cell’s P-V characteristics curve and the tracking of an

MPP-based fuzzy system under various irradiance levels. To track the maximum power from the PV system, fuzzy MPPT control is used. Figure 4 displays the surface view of fuzzy rules along

with the error membership function, duty cycle membership function, and error rete membership function.

Fuzzy MPPT control (a) error membership functions (b) error rete membership function (c) duty cycle (d) surface view of fuzzy rules.

point clamped inverter

A transformerless five-level NPCI (Fig. 5) is a highly efficient and compact power conversion system widely used in renewable energy applications, especially grid-connected photovoltaic (PV)

systems. Unlike traditional transformer-based inverters, transformerless designs eliminate the bulky transformer, resulting in reduced cost, size, and weight. The five-level NPC inverter

further enhances power quality by synthesizing output voltages with five discrete levels, which closely approximate a sinusoidal waveform. This significantly reduces THD, minimizes the need

for large output filters, and improves overall efficiency. Its ability to produce high-quality voltage and current waveforms makes it ideal for complying with grid standards and ensuring

compatibility with sensitive electrical equipment.

The transformerless design introduces challenges, such as common-mode voltage and leakage currents, which can compromise system performance and safety. However, the five-level NPC topology

addresses these issues by employing innovative modulation techniques, such as Space Vector Modulation (SVM), to minimize common-mode voltage and reduce leakage currents effectively.

Additionally, the five-level NPC inverter offers benefits like lower switching losses, balanced voltage stress across components, and modularity for scalability in high-power applications.

These advantages make it a preferred choice for modern PV systems aiming to achieve high efficiency, compactness, and grid compliance without compromising safety and performance.

Circuit of transformerless five-level NPC inverter with coupled inductor.

The use of coupled inductors instead of transformers in inverter-fed grid-connected systems offers several advantages. Coupled inductors eliminate leakage currents caused by parasitic

capacitance, which is common in transformers, thereby enhancing system performance. They are smaller, lighter, and more cost-effective, making the overall system compact and economical. With

lower core losses and no magnetizing current, coupled inductors improve efficiency and reliability by reducing the risk of failure and avoiding issues like DC magnetization and saturation

that transformers often face. Additionally, their simpler design reduces circuit complexity and component count. Coupled inductors provide better filtering characteristics, leading to

improved power quality and reduced harmonic distortion, while also lowering electromagnetic interference (EMI). Furthermore, they are easier to scale for various voltage levels and power

ratings, making them more flexible for modern renewable energy applications. These benefits make coupled inductors a superior choice over transformers in grid-connected inverter

systems.

Operating methods of transformerless five-level NPCI (a) Vdc/2 V (b) -Vdc/2 V (c) Vdc/4 V.

The transformerless five-level NPCI with a coupled inductor, as shown in Fig. 6, is designed to eliminate the need for a transformer, thereby reducing system complexity and addressing

leakage current issues associated with transformers. Each leg of the inverter consists of 8 IGBT power switches, 6 clamping diodes, and 2 coupled inductors. The coupled inductors play a

crucial role in maintaining voltage stability without the use of a transformer. The DC power source is divided across four capacitors (C1, C2, C3, C4) to produce multiple voltage levels.

To produce different output voltage levels, the inverter has 125 switching modes in total. Among these, Fig. 6 depicts three ways of operation. The output voltage is + Vdc/2 in Fig. 6a,

where switches Sa1, Sa2, Sa3, and Sa4 are turned on and capacitors C1 and C2 are energized. The output voltage is − Vdc/2 in Fig. 6b, where switches Sa5, Sa6, Sa7, and Sa8 are turned on and

capacitors C3 and C4 are activated. The output voltage is + Vdc/4 in Fig. 6c, where switches Sa2, Sa3, and Sa4 are turned on and capacitor C1 is activated. The suggested inverter can

efficiently reach the required voltage levels under a variety of switching configurations. The 3-phase, five-level NPCI’s switching modes and voltage level are displayed in Table 1. Here

@-switches ON.

Hexagonal SVM is an advanced control technique used for transformerless five-level NPCI, offering high-quality output waveforms, enhanced efficiency, and improved DC bus voltage utilization.

In this approach, the inverter’s voltage vectors are represented in a hexagonal coordinate system, where the 125 switching states of the five-level NPC inverter form a multi-level hexagonal

structure. The hexagon is divided into six main sectors, each containing subregions that correspond to specific switching combinations, which is represented in Fig. 7. HSVM determines the

reference voltage vector within this hexagonal space and decomposes it into nearby vectors for smooth transitions and minimal voltage ripple.

Capacitor voltage unbalance is one of the major drawback of a NPCI. Generally during the ideal condition, the voltage across the capacitors is equal. In non-ideal condition the voltage

across the capacitors is not equal. The causes for capacitor voltage unbalance is due to the non-uniform in the switching of the power device, dc link capacitors are in non-ideal condition,

unequal commutation of semiconductor devices, asymmetrical phase currents in switching states and injection of third harmonic current in the neutral point. Due to the above reasons the

capacitor voltage imbalance occurs in NPCI. The effects of capacitor voltage unbalance are leads to affects performance of inverter, increase voltage stress increase across the switch,

additional harmonic content in the inverter output voltage and increase in load current magnitude, which leads to increase bearing current and will damage motor bearing of the ac drives.

The modulation technique optimizes switching sequences to reduce power losses and maintain capacitor voltage balance among C1,C2,C3, and C4, which is critical for stable operation in

transformerless systems. By ensuring a continuous common-mode voltage profile, HSVM also minimizes high-frequency leakage currents, a key challenge in transformerless configurations. The

implementation involves calculating the reference vector based on the desired output voltage and phase angle, identifying the sector and subregion, selecting appropriate switching vectors,

and allocating time durations for each vector. This enables precise generation of the output waveform while maintaining system efficiency and reliability. HSVM’s ability to reduce switching

losses, improve harmonic performance, and balance capacitor voltages makes it ideal for applications such as grid-connected renewable energy systems, electric vehicle chargers, and

high-performance motor drives, where it ensures optimal performance and minimal leakage currents.

There are 125 different switching modes in a three-phase, five-level NPC inverter, with each leg having five different switching states: +Vdc/2, +Vdc/4, 0, −Vdc/4, and − Vdc/2. These consist

of 30 medium and big vectors, 60 small vectors, and 5 null (or zero) vectors. Only small vectors exhibit duplicate switching states in the Hexagonal SVM approach, which represents all

switching vectors within a hexagonal region. Each of the six sectors that make up the hexagonal region has four triangular subregions. Figure 8 illustrates the Nearest Switching Vector (NSV)

technique, which is used to choose the switching vectors to efficiently balance the capacitor voltages. This approach prioritizes the use of medium and large vectors, minimizing

fluctuations at the neutral point and ensuring stable inverter operation.

The control strategy employs six sectors, with each sector further divided into sixteen triangles. To achieve voltage balance across the capacitor, NSV technique utilizes various switching

state voltage vectors. Neutral point fluctuations are minimized by using large and medium state vectors.

Demonstration of Hexagonal SVM for five-level NPCI.

The reference vectors are chosen to control the system’s output current and increase the output voltage. The following is the mathematical expression for these

vectors:

where δS1, δS2, and δM1 are the SV1, SV2, and MV of different triangles located in the hexagonal margin, and V* is the reference vector. The following steps are involved in the process for

identifying the reference vector:

Identifying the position of the various sector.

Locating the specific triangle within the sector.

Generating the gating pulses.

The gating time for the NPCI is computed using the equation:

Gating time calculations for Sector − 1.

In relation to M1, M3 and M4’s positions vary by 1.0 and 0.5 h, respectively. When we enter these magnitude values into the equation above, so

obtain,

$$\:and\:T_{M1}=T\:-\:(T_{M4}\:+\:T_{M3})$$ (10)

The same Eq. (6) through (10), can be used to determine the gating time for the other triangles. The 3-phase, five-level NPCI’s switching pulses are produced based on the switching

time.

The average conduction loss of the power switch and diode is calculated as,

Here PCS and PCD are average conduction loss of switch and diode; ICav & IDav are average Switch and Diode currents; ISrms & IDrms are rms current of switch and diode; UCD, UCS, rC & rD are

the voltage and internal resistance of switch and diode, which is taken from the datasheets.

The Efficiency of the 3-level NPC inverter is,

The energy loss during ON period of the switch is obtained

by,

(13)

Here, EON is energy loss during ON period of the switch; RG gate resistance of the switch; IcON is current through switch during ON period; VDC(ON) is applied dc input voltage of inverter;

Tj is junction temperature of the switch.

The total switching loss of the NPC inverter is,

Where SE(ON) & SE(OFF) are energy loss during ON & OFF period of the power switch; fT is fundamental frequency.

The efficiency of the NPC inverter is attained by,

Basen on the equations the power losses and efficiency of the 3-level NPC inverter of the proposed system is obtained.

The simulation of a Hexagonal SVM strategy for a transformerless five-level NPCI integrated into a grid-connected PV system was carried out using MATLAB/Simulink. The results demonstrate

improved output voltage waveforms with reduced Total Harmonic Distortion (THD), ensuring compliance with grid standards. The hexagonal SVM effectively balanced the capacitor voltage while

minimizing neutral point fluctuations, leading to stable operation under varying solar irradiance and load conditions. Efficient power transmission and unity power factor were confirmed by

the inverter’s output voltage and current being synchronized with the grid.

Furthermore, switching losses and component thermal stress were significantly reduced by the switching technique. The resilience of the control technique was confirmed by the system’s

performance under dynamic situations, establishing it as a dependable option for grid-connected PV applications. Figure 9 displays the PV system’s output voltage and current. In Fig. 10, the

suggested system’s rectified output voltage is displayed. Figure 11a and b depict the dynamic operating temperature and the comparison of the optimal DC power obtained with various MPPT

controllers. The fuzzy logic-based MPPT controller offers superior tracking when compared to other traditional MPPT tracking techniques.

PV scheme output current & voltage.

Boosted output of PV voltage.

(a) Dynamic temperature range (b) optimum DC power obtained using various MPPT schemes.

Mitigation of CMV for five-level NPCI (a) SPWM (b) Hysteresis control (c) Hexagonal SVM.

Output voltage of transformerless five-level NPC inverter.

Figure 12 illustrates the common mode voltage mitigation for the suggested transformerless five-level NPCI with connected inductor. This is proof that the suggested hexagonal SVM offers

superior CMV mitigation when compared to other traditional PWM control strategies. Figure 12a illustrates CMV mitigation using the SPWM method with a voltage of 248 V, which is Vdc/2 times

of applied dc input voltage; Fig. 12b illustrates CMV mitigation using the hysteresis control method with a voltage of 168 V, which is Vdc/3 times of applied dc input voltage; and Fig. 12c

illustrates CMV mitigation using the hexagonal SVM method with a voltage of 84 V, which is Vdc/6 times of applied dc input voltage.

displays the transformerless five-level NPCI output voltage, which is 499.6 V. Figure 14 displays the system’s THD analysis; Fig. 14a shows the THD for output voltage, which is 0.42%, and

Fig. 14b shows the THD for output current, which is 3.63%. Figure 15 illustrates the capacitor voltage balancing spanning C1 to C4, where the capacitors’ imbalance is decreased to 1.2%.

Figure 16 displays the output voltage of a transformerless five-level NPCI with a linked inductor, which does away with the need for a transformer and other synchronization devices. Figure 

17 illustrates how hexagonal SVM is used to generate switching pulses for transformerless five-level NPC inverters.

THD mitigation (a) Voltage (b) current.

Capacitor voltage balancing across C1 to C4.

Output voltage of transformerless five-level NPCI with coupled inductor.

control pulses for leg-1 using H-SVM.

The experimental validation of the Transformerless five-Level NPCI employing Hexagonal SVM was conducted using a test bench comprising 16 A IGBT power switches and an FPGA Spartan 6

controller. The results exhibited a high-quality output voltage waveform with significantly mitigated THD, meeting grid interconnection standards. The FPGA-based control ensured precise

implementation of Hexagonal SVM, leading to balanced capacitor voltages and reduced neutral point fluctuations. During operation, the inverter achieved efficient power transfer with minimal

switching losses, maintaining a unity power factor. Under varying load and PV irradiance conditions, the system demonstrated stability and robustness, with the grid-synchronized output

current closely matching the reference waveform. The thermal performance of the IGBT switches indicated uniform heat distribution, ensuring reliable operation. With the potential for

scalability and increased energy efficiency, our results validate the feasibility of the suggested system for sophisticated grid-connected PV applications. Figure 18 displays the five-level

NPC inverter’s experimental output voltage. Additionally, Fig. 19 illustrates the use of hexagonal SVM for capacitor voltage imbalance minimization.

Experimental output voltage of five-level NPC inverter.

Capacitor voltage unbalance minimization using hexagonal SVM.

CMV Mitigation (a) Hysteresis control (b) Hexagonal SVM.

illustrates the CMV mitigation of a transformerless five-level NPCI. Hysteresis control is depicted in Fig. 20a with a voltage of 179 V, or Vdc three times the input voltage, and a hexagonal

SVM with a voltage of 88 V, or Vdc two times the input voltage, in Fig. 20b. Voltage and current experimental THD-FFT analyses are displayed in Fig. 21a and b with 1.26% and 4.98%,

respectively. A transformerless five-level NPC inverter with a linked inductor is demonstrated experimentally in Fig. 22. The experimental setup is a configuration of the suggested

transformerless five-level NPCI with connected inductor system. Comparative analysis of various PWM methods for various inverter parameters is shown in Fig. 23. Table 2 presents a comparison

of different PWM techniques for output voltage, THD reduction, CMV, and capacitor voltage control. Power loss & efficiency comparison for various PWM methods is shown in Table 3.

size imageFig. 22

Experimental THD-FFT analysis (a) For voltage (b) For current.

Comparative analysis of various PWM methods for various inverter parameters.

size tableTable 3 Power loss & efficiency comparison for various PWM methods.Full size tableConclusion

This research presents a transformerless five-level neutral point clamped (NPC) inverter with a coupled inductor for grid-connected PV systems, addressing key challenges such as total

harmonic distortion (THD) reduction, common mode voltage (CMV) mitigation, and neutral current balancing. The proposed system is controlled using Hexagonal Space Vector Modulation (HSVM) to

optimize output voltage levels and enhance overall performance. Through simulation and experimental validation, the proposed inverter demonstrates high efficiency, improved power quality,

and compliance with grid standards under varying operating conditions. The results confirm the effectiveness of the topology in minimizing CMV, reducing THD, and ensuring system stability.

The findings suggest that the proposed system offers a cost-effective and reliable solution for integrating renewable energy into the grid, making it a promising approach for future

sustainable power generation applications.

The highlight of the work includes:

The CMV level is reduced to Vdc/6 times of applied input voltage.

The capacitor unbalance is minimized to 1.2%.

The THD range is minimized to 1.26% for output voltage and 4.98% for output current.

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.

Photovoltaic

Maximum Power Point Tracking

Neutral Point Clamped inverter

Perturb and Observe

Voltage Source Inverter

Total Harmonic Distortion

Nearest Switching Vector

Common Mode Voltage

Capacitor Voltage Unbalance

Modulation Index

Neutral Point Fluctuation

Field Programmable Gate Array

Electromagnetic Interference

Pulse width modulation

Hexagonal Space Vector pulse width modulation

Supply voltage

Output voltage

Photo generated current

Diode current

Shunt current

Output current

Medium Vectors

Small Vectors

Large Vectors

Switching frequency

Capacitor Voltage

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The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work under Grant No. RGP2/306/44. This research was partially funded

by a grant from Multimedia University, Malaysia (MMUI/220086).

Author informationAuthors and Affiliations Department of Electrical and Electronics Engineering, College of Engineering and Technology, SRM Institute of Science and Technology,

Kattankulathur, Chennai, Tamilnadu, 603203, India

R. Palanisamy & K. Vijayakumar

Faculty of Engineering and Informatics, Department of Computer Science & Engineering, Ala-Too International University, Bishkek, Kyrgyzstan

Mohammad Imtiyaz Gulbarga

Department of Industrial Engineering, College of Engineering, King Khalid University, P.O. Box 394, Abha, 61421, Saudi Arabia

Mohammed Al Awadh

Center for Engineering and Technology Innovations, King Khalid University, Abha, 61421, Saudi Arabia

Mohammed Al Awadh

Centre for Intelligent Cloud Computing (CICC), COE of Advanced Cloud, Faculty of Information Science & Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, Melaka, 75450,

Malaysia

Liew Tze Hui

AuthorsR. PalanisamyView author publications You can also search for this author inPubMed Google Scholar

K. VijayakumarView author publications You can also search for this author inPubMed Google Scholar

Mohammad Imtiyaz GulbargaView author publications You can also search for this author inPubMed Google Scholar

Mohammed Al AwadhView author publications You can also search for this author inPubMed Google Scholar

Liew Tze HuiView author publications You can also search for this author inPubMed Google Scholar

R. Palanisamy: Writing – original draft, Methodology, Investigation, Formal analysis, Conceptualization. Vijayakumar K: Writing – original draft, Validation, Methodology, Investigation,

Formal analysis, Conceptualization. Mohammad Imtiyaz Gulbarga: Formal analysis, Methodology, Software, Validation. Mohammed Al Awadh: Visualization, Validation, Methodology, Investigation,

Formal analysis, Conceptualization. Liew Tze Hui : Investigation, Methodology, Software, Validation, Visualization, Writing – review & editing.

Corresponding authors Correspondence to R. Palanisamy or Liew Tze Hui.

The authors declare no competing interests.

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About this articleCite this article Palanisamy, R., Vijayakumar, K., Gulbarga, M.I. et al. Neutral point clamped inverter for enhanced grid connected PV system performance based on hexagonal

space vector modulation. Sci Rep 15, 18881 (2025). https://doi.org/10.1038/s41598-025-02506-w

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Received: 13 January 2025

Accepted: 13 May 2025

Published: 29 May 2025

DOI: https://doi.org/10.1038/s41598-025-02506-w

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KeywordsPhotovoltaic (PV) systemsTotal harmonic distortion (THD)Common mode voltage (CMV)Transformerless five-level neutral point clamped (NPCI) inverterCapacitor voltage unbalance (CVU)