AC Inverter Research Articles

Design, techno-economic evaluation, and experimental testing of grid connected rooftop solar photovoltaic systems for commercial buildings

This study aims to investigate the potential of rooftop solar photovoltaic systems for commercial buildings. Helio-Scope software is utilized to perform simulations to determine the ideal rooftop area for photovoltaic panels. The efficiency of photovoltaic systems is impacted by the shading effects of photovoltaic modules installed in parallel rows. To enhance energy output, the optimal distance between rows is determined, and it is found that 5-feet inter-row spacing provides the best results. The simulation results indicate that with 5-feet inter-row spacing, photovoltaic system has an energy generation of 371.6 MWh, specific yield of 1508.0 kWh/kWp, performance ratio of 82.1%, solar access rate of 98.9%, total solar resource fraction of 96.3% and a total irradiance of 1655.9 kWh/m2. The annual nameplate energy is 425.1 MWh, output energy at irradiance levels is 423.1 MWh, optimal DC output is 378.5 MWh, inverter output is 373.5 MWh, and total energy delivered to the national power grid is 371.6 MWh. The average daily DC inverter input power is 158881.5110 W and the average daily AC inverter output power is 152231.6311 W, showing an inverter efficiency of approximately 95.93%. Moreover, detailed testing of the installed PV system is performed on-site to make sure that equipment’s performance guarantees are achieved, the system is properly installed and its configuration is suitable for commercial operations. The maximum daily output energy generation of an installed photovoltaic (PV) system is 1.33 MWh, and its average energy generation is 1.09 MWh. The voltage of all strings is within the rated range of the inverter, with a maximum voltage of 835 V and a minimum of 698 V, as tested by PV string open-circuit voltage. The inverter efficiency test is also performed, with a maximum efficiency of 98.83% and fill factors ranging from 81.37% to 82.34%. The payback period of a photovoltaic system is 4.22 years and LCOE is 0.0229$/kWh. PV system saved 215569.818 metric tons of CO2 in the first year and a total of approximately 5068976.99 metric tons in 25 years.

Bifurcation analysis and control in a DC–AC inverter with PID controller

AbstractAiming at the rich bifurcation and chaotic characteristics in the inverter with proportion integral derivative (PID) controller, the discrete iterative model of such an inverter was derived based on the stroboscopic mapping theory; the nonlinear evolution and the cause of instability in this inverter are analyzed. It was observed that the low‐frequency oscillation following instability was due to the Hopf bifurcation, which will decrease the power supplied quality by the inverter. To address the potential issue of the system instability caused by nonlinear behaviors, an improved exponential time‐delay feedback control scheme was proposed. The controlled object's output current first subtracted its own delay a period of time to form a difference term, which was subsequently fed into an exponential link to make difference with the constant 1. The resulting value was then fed into a proportional link to obtain the control term, which was applied to the PID controlled inverter in a feedback manner. Moreover, the range of the feedback proportional coefficient was solved via the Jury criterion. Finally, the effectiveness of this scheme was verified through the comparative simulations, demonstrating that this scheme can not only increase the stability domain for each parameter by more than 50% in the PID controlled inverter but also stabilize the quasi‐periodic behavior due to the low scale oscillation caused by the Hopf bifurcation at the switching frequency.

Single‐stage single‐phase multiport DC–AC inverter suitable for standalone applications due to its notable performance in different operation modes

AbstractA new multiport DC–AC converter is proposed for standalone and off‐grid tied applications. The configuration converts power from DC to AC form in a single stage with suitable voltage gain. To increase the certainty of supporting power, the converter is designed to operate in four modes, including battery‐alone mode. The other advantage of the presented work is supplying the output power during unbalanced voltage conditions of the input ports. The advanced features of the converter for being used in standalone applications are related to the suitable placement and structure of the bidirectional port. In addition, the configuration is designed in a way to contain appropriate structural properties such as the existence of a common ground between the DC section and inverter, continuity of input currents, configured by an acceptable number of components, and low‐voltage stress on the DC–DC section's switches. Furthermore, it has an impedance network to protect the inverter's switches in a shoot‐through state. To confirm the converter advantages from the mentioned points of view, it has been compared with similar configurations. A prototype rated at 110 V is prepared to demonstrate the advantages of the converter performance per different conditions. The results of the steady‐state and transient experiments validate the suitability of the presented converter.

Impact on Annual Energy Cost due to Air-Conditioner selection for Hotel Business setup in North India

Energy consumption is a critical factor in determining the overall cost and profitability of a hotel. High energy consumption can significantly increase operating costs, which directly impacts the overall financial performance of a hotel (Filimonau et al., 2011). By reducing energy consumption, hotels can effectively lower their operating costs and increase profitability. This can be achieved through various measures such as implementing energy-efficient lighting systems, optimizing HVAC systems, using smart technologies for better control and monitoring of energy usage, and adopting energy-saving practices in areas such as heating, cooling, and ventilation. Implementing these energy-saving measures can not only reduce the hotel's carbon footprint but also improve its competitiveness in the market (Čingoski & Petrevska, 2018). Additionally, promoting energy conservation in a hotel can also contribute to enhancing its reputation and attracting environmentally conscious guests (Filimonau et al., 2011). Overall, the impact of energy consumption on the cost and profit of a hotel is significant. Keywords Energy consumption, Air-Conditioner Selection, Advance Technologies, Energy Saving, AC Star Rating, Five Star AC, Inverter AC, Split AC, Window AC.

Development of a portable small wind turbine for integration into a mobile cooling technology

In this study, a small wind turbine prototype was developed to provide electric power for a mobile cooling unit The aim of this study was to design and develop a 600-W small wind turbine that can generate electric energy to power a mobile cooling unit used for the storage of fruits and vegetables, mainly for the benefit of smallholder farmers. Smallholder farmers suffer from high postharvest losses, approximated at 50%, some of which can be avoided by using efficient low-cost cooling units, rather than open transport. Cooling slows down the metabolic rate which consequently extends the produce's shelf life and prevents spoilage, allowing farmers to provide high-quality produce to the market. This could potentially increase the farmers’ monetary returns. The study was conducted in KwaZulu-Natal on the road that stretches between Pietermaritzburg and Estcourt. The wind turbine is made of a 600-mm-diameter rotor with three PVC blades, a permanent magnet synchronous generator, a bridge rectifier, a 230-V AC inverter and a battery for energy storage. The wind turbine was tested against three vehicle speeds of 60, 80, and 100 km h−1, and the two opening levels, level 1 at 45∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ$$\\end{document} and level 2 at 80∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ$$\\end{document} relative to the louvre mechanism frame. The results of this study revealed that the power generated by the wind turbine is greatly influenced (p < 0.001) by both the vehicle travelling speed and louvre opening level. The power output of 113.4, 159.6 and 210.0 W per hour was observed for the vehicle speeds of 60, 80 and 100 km h−1, respectively, on louvre opening level 1. The power output of 142.8 W h−1, 268.8 W h−1 and 294.0 W h−1 were observed for a wind speed of 60 km h−1, 80 km h−1, and 100 km h−1, respectively, on Louvre opening level 2. This shows that higher wind speeds (vehicle speeds) produce high-power output which accounts for the small size of the wind turbine rotor. A maximum power coefficient of 0.49 was achieved for this study. The wind turbine can generate the power required to run a cooling technology to a limited extent, thus must have a backup power supply from the diesel engine or be used in a hybrid system.

Offline Parameter Self-Learning Method for Low-Impedance Dual Three-Phase PMSMs: Addressing AC Losses and Inverter Nonlinearity

Offline Parameter Self-Learning Method for Low-Impedance Dual Three-Phase PMSMs: Addressing AC Losses and Inverter Nonlinearity

Real-time thermodynamic monitoring of split inverter ACs: amicrocontroller-driven investigation of performance

Recent technological advancements, particularly in air conditioning cooling systems, have led to rapid developments such as inverter technology. Inverter technology provides various advantages including energy savings compared to non-inverter air conditioners. Globally, the inverter modulates the compressor to continue operation despite reaching the set temperature. This study aimed to monitor the performance of split inverter air conditioners utilizing microcontroller technology. The microcontroller model employed was the ATmega2560, capable of logging each test parameter and displaying in real-time. Additionally, the ATmega2560 integrated sensors including the DS18B20 temperature sensor and PZEM 004-T multifunction electrical sensor. Monitoring occurred over one hour of operation on a 8525 Btu/h capacity split inverter AC. Experimental monitoring results showed the lowest Tsupply at T1 compared to other temperatures, reaching 8°C. At Treturn, both T1 and T2 exhibited identical decreasing trends to 25.5°C around 3000 s. The minimum power variation occurred at P5 relative to other variations. The average power consumption of the split inverter AC was approximately 750 W. The minimum energy consumption observed was at E5 during the study, while the maximum was at E1 with peak energy consumption of 0.96 kWh. Microcontroller-based experimental monitoring can provide real-time results and shows promise for monitoring split inverter AC performance.

Hardware simulator of DC–AC inverters for electric compressors

Hardware simulator of DC–AC inverters for electric compressors

Design and implementation of pulse width modulation gate control signals for two-level three-phase inverters

The switching control circuit in a DC to AC inverter is the critical part that is applied to control the power transistors insulated-gate bipolar transistor (IGBTs) and metal-oxide semiconductor field-effect transistor (MOSFETs). This paper proposes a high-performance and low-cost pulse width modulation (PWM) control signal with a 120º phase shift circuit for a two-level three-phase inverter. Typically, a PWM signal with a 120º phase shift for three-phase inverters is generated with the help of analogue components with more complicated designs and power losses or by using a microcontroller with necessary programming or coding. The proposed solution is to design a 120° three-phase shift circuit based on D flip-flops and the 555-timer to generate the clock signal for the flip-flop input in addition to the dead-time control circuit. The proposed circuit is controlled by one square wave signal as an input signal to generate six output PWM control signals at 50 Hz to operate six MOSFETs in the three-phase inverter. Simulation results in power simulation software PSIM and PROTEUS simulation tools are used to verify the proposed circuit. Hardware implementation of the proposed circuit and three-phase inverter is carried out to validate the performance of the proposed design.

Conceptual design and analysis of a tricycle mounted solar-powered photovoltaic cold room system

Energy crisis in developing countries is worrisome, and this has made the preservation and transportation of medical and perishable food items a common problem. Most conventional refrigeration systems operate with electricity; however, there are regions where it is difficult or not cost efficient to provide electric service. Therefore, this research seeks to solve the problems of inconsistent, irregular and complete non availability of power supply required to keep food products and drugs refrigerated over a long period of time by designing a tricycle mounted solar-powered cold room. The tricycle mounted solar-powered cold room designed consists of a refrigeration system having a compressor, a condenser, an expansion valve and an evaporator; a solar system having a photovoltaic (PV) module, charge regulator, storage battery and DC to AC inverter; and a tricycle for easy distribution and safe delivery of refrigerated items. A comprehensive analytical design was performed on each of the systems and the design results showed that the solar-powered cold room has refrigerating cooling load, PV array size, battery cap, and inverter power of 986 W, 275 W, 94 kWh, and 8000 W respectively. A structural analysis was also carried out on the tricycle chassis using the finite element method on Autodesk Inventor software. The results showed that the maximum von misses stress experienced by tricycle chassis was 56.96 MPa which is significantly lower than the yield strength of the chassis material used in the design, indicating a robust structural integrity and can therefore be used to carry the loads that it will be subjected to without deformation.

Reduced stage three phase multisource hybrid converter for integration of PV and grid power

A three-phase-based Modified Dual Source Inverter has been proposed in this manuscript. The existing three-phase system is plagued with multistage power conversion, reducing its efficiency. The proposed converter can integrate two sources (AC and DC) simultaneously and supplies power to the three-phase load. It can switch its operation from the grid to grid-solar, solar to grid, as per the availability of the source. The inverter can operate as a three-phase DC to AC inverter, AC to AC inverter, and it can use grid and PV power directly with the help of a sino-squo-sino waveform. The system has been studied when switching from one mode to another. The system behavior has been analyzed on MATLAB SIMULINK and experimental setup. The proposed approach has been experimentally validated and operated using a TEXAS-based microcontroller (TMS320F28739d). The proposed method has reduced the THD to 4.32% when operated on solar and grid. The THD is 0.25% when operated on the grid power. The proposed system has also been compared based on components. It uses six IGBTs, One Mosfet and three Bidirectional switches.The reduced number of components reduces switching losses, which increases the system's efficacy and performance.

Analysis of the Willingness to Pay for Energy-Efficient Inverter AC using the Contingent Valuation Method (CVM)

Consumers tend to pay less attention to the hidden long-term energy costs than the more noticeable upfront purchase prices. Regarding this condition, this study will estimate the acceptable additional price for an energy-efficient inverter AC by applying the Contingent Valuation Method (CVM). The study gathers primary data by delivering the questionnaire with the payment card inside to the 328 Semarang City participants as the research sample. Nevertheless, nine respondents indicated their reluctance to buy at an extra price. Hence, this study modified the number of samples to 319 respondents. Based on the data processing, this study found that individual characteristics are critical in determining willingness to purchase energy-efficient inverters AC. The monthly income level factor seems to positively influence the willingness to pay a premium price for an energy-efficient inverter AC. This study also indicated that consumers with higher education levels, especially those familiar with energy-saving concepts, positively impact their willingness to pay a premium price for energy-efficient inverters AC.

Effect Of AC Compressor Modification on Fuel Consumption in Car

The cooling system is a refrigeration technology that is growing, especially regarding the cooling medium (refrigerant), new vehicles nowadays mostly use air conditioning to condition the air in the vehicle's cabin, but for now, there are still many aspects that have not been given much attention, especially the compressor. Compressor systems in vehicles still rely on the engine as a direct drive resulting in increasingly wasteful fuel consumption and reducing the performance of the vehicle. This study analyzes the results of modifying a conventional compressor into an electric compressor by utilizing a split AC compressor whose supply voltage is obtained from a DC to AC inverter on vehicle fuel consumption and the required electrical energy. Inverter modification is highly recommended in the application of car air conditioners, split AC compressors, and others. The results of this research show that AC compressors using split compressors affect fuel consumption.

Robust energy storage system for stable in wind and solar

Energy storage systems (ESS) have become a conspicuous research hotspot since they store power and supply it during peak hours. Existing storage systems must be replaced by advanced energy storage with improved performance, energy management, and a control interface due to issues with size, dependability, and charging/discharging. The suggested robust energy retention system uses a battery and a super-capacitor to generate power from wind and solar energy. A Multiport DC converter with a buck-boost capacitor is used to properly discharge the stored energy to DC loads via a DC bus. The inverter is then delivered to a Power Flow Controller (PFC) and a Voltage Source Inverter (VSI). The Gravitational Search Algorithm (GSA) method optimizes the power controller settings based on the fluctuation of the system's active and reactive power. The optimization method ensures improved power flow while dealing with the least amount of power variance in imbalanced load situations. Based on the power variation, the proposed method generates appropriate control signals for the inverter system. The covers convert the inverter and reduce harmonics with a controller. Furthermore, the inverter AC supplied to the AC bus is converted into reactive power by an inductive load, and unwanted signals and harmonics are extracted using a Cascaded C-type filter. As a result, the described method has preserved total harmonic distortion, electrical efficiency, and finer transient stability.

A coordinated power flow control strategy to enhance the reliability of hybrid ac/dc power grids during cascading faults

Cascading fault is a newly emerging challenge in hybrid ac/dc grids including current source converters (CSCs) which commences from a dc or a long-lasting severe inverter ac fault and ultimately provokes a total blackout at the inverter ac side. Nevertheless, since the cascading faults emanating from dc faults are not accompanied by commutation failure, the prevailing commutation failure elimination strategies are unable to inhibit these contingencies. To obviate such a challenge, this paper proposes a coordinated power flow control strategy which can preclude the blackouts caused by cascading faults initiated from either dc or inverter ac faults, thereby improving the reliability of hybrid ac/dc power grids. To achieve this, a back-to-back voltage source converter (B2B-VSC) is employed which is responsible for controlling both the inverter ac bus voltage and the active power flow of its connected ac line. This would not only mitigate the probability of commutation failure due to the reinforced inverter ac bus voltage, but also enhance the power flow flexibility of the power grid during both normal and fault conditions. In addition, the cost associated with implementation of the proposed strategy is much less than installing several backup parallel lines which are useless under no-fault circumstances. Finally, the practical viability of the proposed strategy is scrutinized through laboratory testing using co-simulation of RTDS and Opal-RT simulators. The obtained results show that the developed strategy can effectively manage the power flow of B2B-VSC and CSC-HVDC systems during different possible fault cases so that the power outage at the inverter ac side is minimized.

Design of 10 kW, 400 kHz AC Power Supply for Ferrite Inductively Coupled Plasma

This article describes the design and implementation of a 10 kW, 400 kHz ac power supply for a ferrite inductively coupled plasma (ICP) reactor. The developed power supply is composed of an ac inverter and a front-end converter not only to offer stable dc input voltage for the inverter but also to respond to the dynamic load characteristic of the plasma reactor. A brief introduction of a series-parallel resonant converter (SPRC) with a trapezoidal approximation and determining a design point considering a wide load range are described. In the case of the inverter, a low-loaded quality factor design method based on the analysis of a series-parallel resonant inverter (SPRI) to obtain high efficiency is proposed. With respect to the plasma ignition, a control logic without an additional plasma ignition circuit is proposed. Finally, the performance of the developed power supply is demonstrated under various experimental conditions including an experiment with a ferrite ICP load.

Voltage-Fed single stage inverter for generating systems with Multi-Input inverter using Pulse Width Modulation

A voltage-fed single-stage multiple-input inverter is developed for hybrid wind/photovoltaic energy generating systems. In this research proposes a revolutionary multi-input inverter that simplifies and reduces the power system's cost. Inverter comprises the DC-DC converters and full-bridge ac inverters, which are buck/buck-boost. This study proposed a multi-input converter for hybrid photovoltaic and wind energy systems, with the basis and enhanced functionalities created by the scholars included in the design. A Novel Predictive Current Control Algorithm (NPCCA) is proposed for Hybrid a renewable energy source which depends on improved space-vector Pulse-Width-Modulation (PWM) to provide high-quality current and quick dynamic reaction to incorporate changes. Also discussed are the solar array and wind turbine output power characteristics. The Maximum Power Point-Tracking (MPPT) methodology is accomplished using the perturbation and observation methods to resist all non-linearities in the typical I-V curves. The proposed multi-input converters results in lower production costs for the converters since they use fewer semiconductors and take up less space. Soft-starting and circuit safety features are added for real-world uses. The simulation outcome of the NPCCA framework attained in terms of accuracy is 92% and efficiency is 92% when compared with the other existing approaches.

Three-phase bidirectional active split source inverter for automotive traction application

The Split Source Inverter (SSI) is an attractive single-stage boost DC–AC converter topology. It requires fewer components than the Z-source inverter to achieve the boost function and also maintains a continuous input current. However, a significant drawback of this topology is its limited DC-bus voltage utilization. This paper introduces a new inverter topology derived from the SSI, aimed at addressing the DC voltage utilization issue and assessing its viability for traction applications. The new three-phase single-stage boost DC–AC inverter topology is named B-ASSI, and a potential modulation scheme is proposed to accompany it. To verify their functionality, the proposed converter and modulation scheme are simulated using Matlab/Simulink. Furthermore, a Proof of Concept (POC) is executed to experimentally validate the performance of the proposed inverter topology.

Unsustainable competitive advantage: a case of Exalta

Learning outcomes The case deals with the issue of gaining a sustainable competitive advantage (SCA) in the solar energy market. After completing the case, the student will be able to– develop and apply conventional models of competitive advantage and core competency;– comprehend each step of the business process from a core competency viewpoint;– consider the value of sustainability solutions from a strategic standpoint; and– offer practical templates for creating and implementing a strategy. Case overview/synopsis This case depicts the challenges faced by Exalta in gaining a SCA because of the imitation of its products by competitors. Exalta, formed in 2008, was among the well-known innovative companies in the solar energy industry in India. In the first 12 years, the company focused primarily on unmet customer demand and developed innovative solar products to address those demands. Overall, over 300 products were launched in the initial years to address the new emerging customer demands. Solar AC, bikes and ventilators were among the popular ones. However, all of its product technology was copied by competitors. In 2021, troubled Exalta was incubated at IIT-Kanpur primarily for a single product, “Magic Inverter,” with substantial funding and IP protection. Despite attempts, Exalta could not capture a recognized market share. In this case, the company’s founder and CEO, Ashutosh Verma, is contemplating two options to gain an SCA: hold the existing and new products or fold the old ones and continue with one or two flagship products, i.e. Magic Inverter and Solar AC. Complexity academic level Graduate, postgraduate level and executive-level courses. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes. Subject code CSS 11: Strategy. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/EEMCS-12-2022-0526/

Auxiliary Power Supply System with Parallel-Connected DC–AC Inverters for Low-Floor Light Rail Vehicle

This research proposes a roof-mounted auxiliary power supply (APS) system for 600 VDC low-floor light rail vehicles (LRVs). The proposed APS system consists of five parallel-connected dc–ac inverter modules (modules 1–5). Inverter modules 1 and 2 are three-phase dc–ac inverters for the compressor motors of the air conditioning system, and inverter modules 3 and 4 are three-phase dc–ac inverters for the air pump motors of the air supply system. Inverter module 5 is a single-phase dc–ac inverter for the 220 VAC power supply of onboard electric loads. Simulations and experiments were carried out under variable load torques and output frequencies for modules 1–4 and under full and no resistive loads for module 5. The measured total input current and total input power of the proposed APS system under the full-load condition are 114.36 A and 68.84 kW. The total efficiency of the proposed APS system (modules 1–5) is 97.05%. The proposed APS system is suitable for 600 VDC low-floor LRVs. The novelty of this research lies in the use of five parallel-connected inverter modules, as opposed to the three-phase output transformer or isolated dc–dc converter in the early and conventional APS systems. Specifically, the proposed APS system requires neither a three-phase output transformer nor an isolated dc–dc converter.