International Journal of Power and Energy Conversion (13 papers in press)

Regular Issues

• Design and verification of FPGA based prototype of VSG controller  
  by Praveen Kumar, Vinendra Sairamkrishna, Sachidananda Sen 
  Abstract: As distributed generation leads to loss of inertia that causes higher fluctuations in system dynamics and reduced frequency stability. This effect is very high in the case of microgrids (MGs). A virtual synchronous generator (VSG), which is the imitation of the synchronous generator, ascertained to be a reliable way to bring back the lost inertia. However, as phase-locked loop (PLL) is nonlinear, so its use in measurement of frequency and rate of change of frequency can degrade the response time, and it can become worst with lower voltages. In this work, a VSG controller without using PLL is proposed and the controller does not depend on the magnitude of voltage. The Verilog hardware description language is used to develop the hardware prototype of the VSG controller. The hardware is developed on the FPGA board viz. SPARTAN-3E FPGA. The prototype is verified and validated by the hardware-in-loop (HIL) in a real-time environment using a real-time digital simulator. Its performance is tested under various disturbances in the MG and results are compared with MG without VSG and with simulated VSG. Results suggests that the hardware prototype of VSG is stabilising disturbances in the MG to a great extent by providing virtual inertia.
  Keywords: field programmable gate array; FPGA; microgrid; phase locked loop; PLL; virtual inertia; virtual synchronous generator; VSG.
  
  
• Mass energy transfer effects of PEM fuel cell flow channels with correlation between geometric parameters and operating conditions  
  by Hoe-Gil Lee, Dakota Messer 
  Abstract: Proton exchange membrane fuel cells (PEMFC) are integrated to explore the effects of the design and analysis of the flow channel plate in a proton exchange membrane fuel cell. It investigates three primary channel designs under different operating conditions and examines the pressure and velocity distribution across the plate. The numerical and experimental results indicate that the grid-designed channel pattern is the most efficient for achieving an even pressure and velocity distribution across the flow channel plate. Testing three flow patterns with three materials and five inlet velocities revealed the grid design’s efficiency, ensuring smooth fluid distribution, especially with graphite material at 0.004 kg/s. The roughness analyses emphasised the efficiency of a level 0, correlating with decreased pressure and velocity, aligning with expected turbulent flow. The experimental set focused on grid design thickness variations, with a 0.4-inch thickness proving efficient, particularly at 0.004 kg/s.
  Keywords: bipolar plate; PEMFC; performance analysis; CFD simulation; flow channels.
  
  
• Machine learning model for wind direction and speed prediction  
  by J. Gowrishankar, K. Tamilselvan, N. Sakthi Saravanan, B. Murali 
  Abstract: The capacity to estimate wind direction and speed is essential for both the generation of renewable energy and the forecasting of weather. Near the ground, the performance of the mechanistic models that are the foundation of conventional forecasting is quite low. We will explore a different data-driven strategy that is based on supervised learning. We train supervised learning algorithms utilising the previous history of wind data. We use data from individual locations and horizons to conduct a systematic comparison of a number of algorithms, during which we change the input/output variables, the amount of memory, and whether or not the model is linear or non-linear. According to our findings, the ideal design as well as the performance of the system varies depending on the region. Our technique achieves an improvement in performance of 0.3 m/s on average when it is applied to datasets that are accessible to the public.
  Keywords: machine learning model; input/output variables; linear vs. non-linear model.
  
  
• Synthesis, characterisation and stability testing of graphene enhanced paraffin wax phase change material for energy storage  
  by Jvalant Trivedi, Mitesh Shah, Sachin Gupta, Aditya Bais 
  Abstract: Non-conventional sources of thermal energy must be widely recognised for effective environmental protection. Solar thermal is an effective replacement for regular sources but due to its intermittent nature depends largely on environmental conditions. Passive heat storage mediums such as phase change material (PCM) stabilise the energy output of non-conventional sources. Paraffin wax is the most common PCM used in heat storage applications such as solar thermal energy storage. Paraffin wax suffers from low thermal conductivity which makes it sluggish in charging-discharging time. The current study has experimentally investigated the effect of graphene nanoplatelet in weight concentrations of 1wt%, 3wt% and 5wt% in paraffin wax as base PCM. The results indicated that after each successive addition of nanoplatelets, an increment in thermal conductivity of 20.17% (1wt%), 37.34% (3wt%), and 58.80% (5wt%) were measured respectively when compared to base PCM. At the same time, the latent heat decreased with the maximum dip observed in the 5wt% sample. A stability analysis was conducted for the effect of adding SDBS surfactant as a stabiliser on the NEPCMs’ thermal conductivity after various cycles. A good hold on thermal conductivity with the SDBS Sample was illustrated.
  Keywords: phase change; energy storage; nanoplatelets; graphene; phase change material; PCM.
  
  
• A review paper on research advancement on analysis of substation grounding design  
  by Avani Mistry, Kaustubh Vyas, Ravindrakumar Yadav 
  Abstract: For ensuring the safety of persons and equipment in substation, ground potential rise (GPR) should be within the acceptable limits, IEEE Standard 80-2013 is widely accepted guide for substation grounding system design. This review papers deals with the various grounding system parameters, their mathematical equations, designs of grounding system in the substation soil, design and development of software, evaluating the results obtained and methods for improving grounding safety by suggesting alternative measures. Various case studies have been taken into account to analyse the latest trends in this field. Softwares like ESGSD, CDEGS are designed for implementing concepts given in the IEEE 80-2013 guide into analytical domains to obtain grid design and calculating various parameters of the design. Detailed analysis of soil resistivity is also done in this paper. Thus, judiciously designed grounding system is cost effective and it also increases the level of safety of person-equipments to acceptable level.
  Keywords: grounding; ground potential rise; GPR; touch potential; step potential; ground grid; soil resistivity.
  
  
• Biomass as an alternative solution to energy production and reduction of the greenhouse gas emissions: a review  
  by Hafida Abouallal, Ayoub Najah El Idrissi, Nadia Dkhireche, Mohammed Ebn Touhami 
  Abstract: The increase in population and the expansion of transportation, agriculture, and industry drive the need for energy, leading to a reliance on fossil fuels as the primary energy source. This reliance results in heightened greenhouse gas emissions and environmental damage. To address this, efforts have been made to harness the diverse range of available biomass for energy production, including gas, heat, and electricity through various conversion methods. This article explores the global availability of biomass for energy production, current energy consumption and production trends, biomass classifications and sources, conversion techniques, challenges hindering biomass implementation, and the potential of biomass as an alternative energy source alongside wind, geothermal, and hydroelectric power to eventually replace fossil fuels. The analysis indicates that biomass holds promise for energy generation and can complement other renewable resources in transitioning away from fossil fuels.
  Keywords: biomass availability; energy conversion methods; biomass barriers; biomass energy production.
  
  
• Developing and simulating an inexpensive solar irradiance metre for photovoltaic utilisation  
  by Mohammed Rhiat, Mohammed Kerrouchi, Anas Hassari, Mustapha Melhaoui, Ilyas Atmane, Mostafa El Ouariachi, Pascal Schmitz, Bachir Benhala, Kamal Hirech 
  Abstract: Our study introduces a cost-effective design for a solar irradiance metre that uses a photovoltaic (PV) cell, offering an affordable alternative to traditionally expensive irradiance measuring devices like pyranometers. The core idea of our approach is to establish a straightforward correlation between the solar irradiance and the short circuit current produced by the PV cell. Through detailed simulations, we have shown that it is possible to accurately assess solar irradiance by monitoring the voltage difference across a shunt resistor linked to the PV cell. This voltage fluctuation is then amplified, filtered, and converted into a digital signal by a microcontroller, with real-time results promptly displayed on a small LCD screen for immediate feedback. Designed for use in solar energy projects, our system enables effective monitoring of direct solar irradiance, thus aiding in the estimation of power generation by PV panels.
  Keywords: photovoltaic cell; solar irradiance; metre; electronics; energy; power; measurement; acquisition; instrument.
  
  
• Intelligent fault prediction method for traction transformers based on IGWO-SVM and QPSO-LSTM  
  by Haigang Zhang, Zizhuo Wang, Haoqiang Zhou, Song Zeng, Ming Yin, Junpeng Xu, Bulai Wang, Jinbai Zou 
  Abstract: To address the issue of imprecise fault diagnosis and forecasting in traction transformers, this study introduces a composite algorithm that integrates IGWO-SVM and QPSO-LSTM to realise the fault prediction of traction transformer. In this research, the focus is on utilising the concentration levels of dissolved gases in the oil of traction transformers as training data. A fault diagnosis model is constructed leveraging the capabilities of support vector machine (SVM) technology. To improve the performance of the model, this paper adopts an improved grey wolf optimisation algorithm (IGWO), which adjusts the parameters of SVM, enabling it to diagnose the faults of traction transformer effectively. To predict the faults of the traction transformer, this study introduces a model based on the long short-term memory (LSTM) network, which is further enhanced by the integration of the quantum particle swarm optimisation algorithm (QPSO). The QPSO algorithm is employed to fine-tune the parameters of the LSTM network, thereby enhancing the precision and efficiency of its predictive capabilities. Through experimental comparisons with alternative methodologies, the effectiveness and superiority of the proposed algorithm in fault diagnosis and prediction are verified, and the application value of the proposed algorithm in the field of traction transformer fault prediction is demonstrated.
  Keywords: traction transformer; fault prediction; gas concentration; improved grey wolf optimisation algorithm; IGWO; support vector machine; SVM; long short-term memory; LSTM; quantum particle swarm optimisation algorithm; QPSO.
  
  
• Influence of performance and emission of diesel engine with alumina nano material-based catalyst biodiesel using IoT  
  by B. Venkatesh, Mudassir Khan, J. Chinna Babu, C.H. Nagaraju, R. Madhan Mohan 
  Abstract: In this study, the performance and emissions of Al2O3 alkaline cottonseed biodiesel-powered compression ignition engines were predicted. An experiment was conducted using different biodiesel blends made from cottonseed oil under various loading conditions. Biodiesel was produced using ethanol and Cao-mg/Al2O3 as catalysts through the transesterification process and blended with diesel to produce CBDN10, CBDN20, CBDN30, and CBDN40. The CBDN20 blends showed an evident reduction in fuel consumption by 8% and a 12% improvement in thermal efficiency at high static thrust. The use of these blends resulted in minimal CO, CO2 , and NOx emissions from engines. These emissions were monitored by an IoT system and analysed with gas analysers, which revealed CBDN20s ability to reduce nitrogen oxide and hydrocarbon emissions compared to diesel. Additionally, CBDN20 demonstrated improved thermal efficiency and reduced brake-specific fuel consumption compared to the other blends.
  Keywords: compression ignition engine; cotton seed oil; emission; IoT; performance.
  
  
• Modified T2-DAB converter with bidirectional power flow capability and reduced voltage stress suitable for DC microgrid integration  
  by Kalash Srivastava, Abhik Jitendra Gazdha, Rakesh Maurya, Shailendra Kumar 
  Abstract: This paper presents a modified three-phase dual-active bridge converter (3p-DAB) for the charging/discharging of electric vehicle (EV) batteries. The proposed converter has two distinct features namely: 1) small resistance can be used because the switches are only under one-third of their corresponding voltage stress. As a result, conduction losses are decreased; 2) all switches are turned ON/OFF with soft switching to minimise switching losses. In this paper, mathematical modelling, control, and design of suggested three-phase DAB converter (T2-DAB)-based EV battery charging system are carried out under various operating conditions. In order to control the power flow, a single-phase shift (SPS) modulation strategy is employed during the constant current (CC) and constant voltage (CV) charging modes. A prototype of the suggested T2-DAB converter is developed in the laboratory. The comparison of experimental findings to the theoretical analysis is found favourable.
  Keywords: battery charging; CC/CV charging; DAB converters; electric vehicle; soft switching.
  
  
• Power quality improvement in renewable energy integrated grid: a review  
  by Mathewos Lolamo, Rajan Kumar, Veena Sharma 
  Abstract: Incorporating renewable energy sources (RES), like wind and solar energy, is crucial for combating climate change and promoting sustainability. However, it introduces challenges to power quality (PQ) in distribution systems due to RES output variability, including voltage and frequency fluctuations and harmonics. Distributed flexible alternating current transmission system (DFACTS) devices like unified power quality conditioner and distributed static compensator effectively mitigate these challenges when appropriately controlled. Integrating energy storage systems (ESSs) like battery ESS with these devices and controlling them efficiently using traditional, AI-based, or adaptive control algorithms further enhances the mitigation performance of PQ in RES-connected grids. This review highlights PQ issues, categorisation, and mitigation strategies. It also highlights improving PQ in RES-integrated grids by enhancing DFACTS device performance through ESS combination and effective control. This review synthesises PQ enhancement strategies in RES-integrated grids from existing literature to support future research.
  Keywords: control technique; DFACTS devices; energy storage system; power quality; renewable energy source.
  
  
• Reliability assessment of Fresnel lens under UV light for concentrated photovoltaic applications in Saudi Arabia  
  by Fahad Al-Alweet, Fawaz S. Al Hadlaq, Fawwaz A. Alkhaldi, Mohamed Sabry, Effat A. Rashed, Abdul-Wali Ajlouni 
  Abstract: Reliability testing is an important part of the life cycle of any product. Before launching a product for public use it is very important to perform a reliability test under severe conditions. A concentrated photovoltaic (CPV) plant consists of many components that undergo hours of accelerated testing before making their way to the market. A typical refractive CPV module consists of a Fresnel lens, a secondary optical element (SOE), and a solar cell. The Fresnel lens collects light and focuses it onto the solar cell through SOE. Continuous operation in sunlight has deteriorating effects on the lens and all the components inside the module. The Fresnel lens must be tested for reliable performance in ultraviolet light and other weather conditions like rain, hails, wind, sand, etc. The purpose of this research is to observe and analyse the effect of Ultraviolet rays with different intensities on the Poly Methyl Methacrylate (PMMA) Fresnel lens that is used frequently in refractive CPV designs. UV radiation causes photolysis in PMMA and hence breaks down large PMMA chains into smaller MMA monomers. Hence, the transmissivity dropped by 6% on average by the end of 50kWh/m2. This is because of increased yellowness, and the efficiency dropped depending on how much light is converted by the CPV.
  Keywords: reliability testing; Fresnel lens; concentrated photovoltaic; CPV; ultra-violet.
  
  
• Solar PV-fed cascaded multilevel inverters employing zeta converter  
  by Aquib Mehdi Naqvi, Pushkar Tripathi, S.P. Singh 
  Abstract: The photovoltaic cell produces DC power, while residential, industrial loads, and most modern equipment typically require AC power. Thus, there is a need for power converters that can efficiently convert DC to AC. Although two-level inverters are commonly used for this purpose, they suffer from higher total harmonic distortion (THD) and switching stresses. Multilevel inverter (MLI) technology emerges as an effective solution for high-power medium-voltage energy control. This paper examines cascaded multilevel inverters (CMLIs) of varying levels and multiple-carrier sinusoidal switching techniques, conducting a comparative analysis to identify the most suitable switching technique for implementation in solar stand-alone MLIs. Additionally, the study adjusts the duty ratio of the Zeta converter to optimise power extraction from the solar PV system. The primary focus is on the application of CMLIs in stand-alone solar photovoltaic systems, with the study conducted in the Simulink/MATLAB environment.
  Keywords: inverter; multilevel inverter; MLI; cascaded multilevel; total harmonic distortion; THD; SPWM; Simulink; solar; photovoltaic; maximum power point tracking; MPPT; perturb and observe; P&O; zeta converter; multiple-carrier SPWM.