Power Generation Supply Research Articles

A new generation of power supplies for pulsed loads

Pulsed power supply systems are employed in many fusion projects and in other scientific applications. A novel power supply approach and a first prototype unit were specifically developed to feed pulsed loads (low duty cycle), as the resistive or superconducting coils used to produce high magnetic fields for some seconds or longer.Thanks to the integrated energy storage, the high pulsed power required for the load is not drawn directly from the electrical grid. In fact, a huge amount of energy can be stored at low power (even through a single-phase 10 A plug, as normally used for household appliance). A significant fraction of the energy stored in the load can be recovered for successive operations. Without such energy storage, all the power supply devices and the upstream chain must be oversized and installed only in locations provided with adequate power.The first power supply unit (2 kA) was able to replace a previous system with comparable performances, but the old system occupies an extremely larger volume and needs a 20-kV connection at the input. Moreover, a specific solution was implemented to achieve a very fast (600 kW) energization of the magnets.The energy storage capability is intrinsically scalable: the setup can be rearranged and the storable energy can be updated even after the installation (for example, to increase the pulse duration).

Solid-State High-Voltage Pulse Generator for Low Temperature Plasma Ion Mobility Spectrometry

Low-temperature plasma ion mobility spectrometry (LTP-IMS) is the method to identify some materials by measuring concentration of gas phase ions. IMS used in a wide range of laboratory-based biomedical research studies. A nanosecond pulse generator is necessary for LTP-IMS apparatus to enable direct analysis of various chemical compounds without having to evaporate the analyte or seek a solvent or any reagent. In this paper, a dual Marx pulsed generator for LTP-IMS Ionization power supply is proposed based on a new combination of some solid-state switches including insulated gate bipolar transistor (IGBT) and avalanche bipolar junction transistors (BJTs). The compact dual Marx generator is composed of a series of avalanche BJTs and an IGBT as the trigger switch, where its rise time is reduced from 100 to 5 ns by using an avalanche BJT in its command circuit. In this way, a controllable high-voltage pulse generator has designed, built, and tested. The proposed circuit can be used to generate the repetitive high-voltage pulses necessary for low temperature ionization in advanced IMS apparatus. The output voltage has an amplitude of up to 6 kV with pulse widths in the range of 40–1000 ns and pulse repetition rates up to 2 kHz, having rise time and fall time less than 10 ns independent of the load specifications.

Development and testing of the genetic algorithm to select a scenario of distributed generation power supply system

The rapid development of small distributed energy economy requires the justification and design of methods and models for planning the development of energy systems using distributed generation sources. We have studied the possibility of using the genetic algorithm to solve the problem of selecting a scenario of distributed generation power supply system. To do this, a problem-solving mechanism was developed in the MATLAB environment based on the genetic algorithm and its program code was built. In order to test the created genetic algorithm for a hypothetical large consumer of electrical and heat power with typical load curves, an optimal scenario of a power supply system based on distributed generation was searched. The analysis of the calculation results carried out using the proposed algorithm, evaluation of the model’s behavior when the initial data changes, indicate its efficiency and effectiveness.

Influence of Inter-turn Short-Circuit Fault Considering Loop Current on Electromagnetic Field of High-Speed Permanent Magnet Generator with Gramme Ring Windings

As a kind of emergency power supply in military field, the high-speed permanent magnet generator (HSPMG) has attracted wide attention to its healthy condition. The loop current (LC) of the inter-turn short-circuit (ITSC) fault seriously endangers the generator unit operation stability and power supply reliability. In order to study the influence of pulsating magnetic field produced by LC on the electromagnetic field, the two-dimensional finite element model (FEM) of the 117 kW, 60000 rpm HSPMG is established. By comparing calculation result and test data, the accuracy of the model is verified. The field-circuit coupling method is used to reveal the change mechanism of magnetic field symmetry when ITSC fault occurs. By comparing the spatial distribution of the air-gap flux density, the relationship among the spatial distribution of the air-gap flux density, the elliptical rotating magneto-motive force (MMF) and the current phase angle is determined. The variation of the amplitude of the air-gap flux density space harmonic under different fault degree is studied, and the fault characteristics of ITSC fault are obtained, which provides a reference for ITSC fault diagnosis and fault degree identification. In addition, the research also laid a theoretical foundation for the next analysis of the loss and temperature field.

A novel hybrid renewable solar energy solution for continuous heat and power supply to standalone-alone applications with ultimate reliability and cost effectiveness

This study investigates an integrated energy system designed to supply 100% heat and power to a remote application, renewably. The system comprises a solar photovoltaic (PV) system with hydrogen-based energy storage (SH), a fuel cell heat recovery arrangement, an electric inline heater (powered by the PVs), and a solar thermal system (ST), altogether operating as a renewable combined heat and power solution. A theoretical simulation model is developed in MATLAB to conduct this study. The addition of the inline heater (powered by the PVs) resulted in improving the overall reliability of this integrated renewable energy arrangement from ∼95% to 100% with no additional costs. Additionally, the system is competitive against diesel generator (for power supply) and gas hot water system that is mostly used conventionally in remote areas.

Reduction of Crude Oil Production Cost in Nigerian Indigenous Company using Activity Based Costing

The aim of this study is to investigate the impact of activity based costing in reducing crude oil production cost in Nigerian indigenous oil and gas company. This research work identified strategies to effectively reduce the cost of crude oil production by adopting a cost reduction tool for crude oil production and to establish a good crude oil flow to the surface for production. Activity based costing was the cost reduction tool used for this work. The tool helps to differentiate between value added costing and non-value added costing. Non-value added costs must be reduced or eliminated during production so as to maximise profit. Data was collected from an indigenous oil service company. The collated data were tabulated and graphs were plotted with the aid of Microsoft excel. The analysis revealed a total sum of ? 416,978,977 was wrongly spent for a duration of three years on crude oil production due to non-value added costing. The activities are: poor transportation of crude oil, that is, use of mobile tanker for haulage instead of laying 4 inches coated pipes for a distance of 5km and contracting the treatment of produced water to a contractor instead of setting up a water treatment plant. Also, using a diesel engine generator for electric power supply while gas was available as a fuel gas for natural gas consuming generator was a non-value added activity. Lastly, inadequate oil well flowing practice by flowing the well through an adjustable choke for a long period of time instead of using a fixed choke. This is a huge loss for indigenous oil producing fields operated by an indigenous oil service company in Nigeria. The loss was due to inability of the producers/field location owners to set up few equipment to meet up with complete operation standard.

Reduction of Crude Oil Production Cost in Nigerian Indigenous Company using Activity Based Costing

The aim of this study is to investigate the impact of activity based costing in reducing crude oil production cost in Nigerian indigenous oil and gas company. This research work identified strategies to effectively reduce the cost of crude oil production by adopting a cost reduction tool for crude oil production and to establish a good crude oil flow to the surface for production. Activity based costing was the cost reduction tool used for this work. The tool helps to differentiate between value added costing and non-value added costing. Non-value added costs must be reduced or eliminated during production so as to maximise profit. Data was collected from an indigenous oil service company. The collated data were tabulated and graphs were plotted with the aid of Microsoft excel. The analysis revealed a total sum of ₦ 416,978,977 was wrongly spent for a duration of three years on crude oil production due to non-value added costing. The activities are: poor transportation of crude oil, that is, use of mobile tanker for haulage instead of laying 4 inches coated pipes for a distance of 5km and contracting the treatment of produced water to a contractor instead of setting up a water treatment plant. Also, using a diesel engine generator for electric power supply while gas was available as a fuel gas for natural gas consuming generator was a non-value added activity. Lastly, inadequate oil well flowing practice by flowing the well through an adjustable choke for a long period of time instead of using a fixed choke. This is a huge loss for indigenous oil producing fields operated by an indigenous oil service company in Nigeria. The loss was due to inability of the producers/field location owners to set up few equipment to meet up with complete operation standard.

A Novel, Low-Cost and Reliable Workbench for Optimal Voltage Distribution on Piezoelectric Array Actuators

The vibration control of structures is a valuable technique to increase their integrity and life-cycle. Among smart materials, the passive and active control systems based on piezoelectric elements have been studied in depth. Since the size and location of the piezo-elements on the structure are relevant matters for the damping efficiency, many works have focused on their placement optimization. Under certain circumstances, some structures may be excited by more vibration modes at the same time; hence, the signal conditioning system of the piezoelectric actuators must be capable of adjusting the driving signal in terms of voltage distribution, frequencies and associated amplitudes in order to maximize the damping efficiency. Moreover, in some applications, it could be useful to individually control each actuator therefore tailor-made power supply and signal generation systems are often necessary. This work suggests a low-cost and reliable workbench that overcomes the afore mentioned problems. The system consists of: (1) two arrays of 13 piezoceramic plates which have been glued on an aluminium beam, (2) ad hoc power supply equipment, and (3) mechanical relays arrays managed by a microcontroller for the individual handling of their operating modes. Furthermore, an Arduino board and an in-house software have been implemented in order to perform a task on each relay that is in turn wired to a single piezoelectric plate (PP). The performance of the developed system is evaluated in terms of noise and distortion of the testing signal measured at different points of the workbench. The results show that the proposed workbench may represent a good trade-off between affordability, accuracy and reliability and it can be used for several research purposes.

Stand-alone power supply system with DC photo-diesel source

An object of research is a diesel power supply system of the decentralized village of Tokma, Irkutsk Region, Russia. The objective is to increase the contribution of the PV part of a photo-diesel electrical system operating in parallel with a diesel power plant to a stand-alone distribution network of DC compared to parallel PV and diesel stations operating on AC; quality improvement and voltage stabilization in the electrical network; cost reduction of generated electricity. Optimization of the characteristics of a stand-alone power supply system at a DC is a difficult task, due to the impossibility of conducting tests in a real electric power system, and the use of physical modeling because of its extreme complexity. Given this fact, the task is to design software and hardware tools for optimizing the parameters of a DC photo-diesel power system. The developed models use MS Excel, MatLab/Simulink software packages, as well as weather data bases. A software tool has been developed that allows for simulation modeling of operating modes of photo-diesel power supply systems, generation, consumption and insolation level of a decentralized consumer, as well as determining rational technical and economic parameters; criteria of expediency and efficiency of constructing photo-diesel electric systems with DC have been identified. As a result, the level of voltage drop is reduced compared to the AC power supply system, the cost of 1 kWh of electrical energy is lower than in the AC power supply system, and the negative environmental impact is reduced.

Assessment of the transverse roughness of the thin-walled cooler for the robot control system made using CAM programming

The article deals with design and design of a thin-walled heat sink for the robot control system, the measurement of the transverse roughness of the touch surfaces and the programming procedure in Autodesk Inventor 2019 software. In this software, a design of the 3D model of the heat sink generated based on power supply and NC code generation for the Fanuc control system. The production it-self carried out on the CNC Vertical Machining Center Pinnacle 2100 with this control system. The longitudinal surface roughness was measured with a Mi-tutoyo SJ 400 dredger and the measurement result was the maximum Ra = 0.69 μm and Rz = 4.1 μμm.

Green hybrid power system based on triboelectric nanogenerator for wearable/portable electronics

Triboelectric nanogenerator (TENG) is an important green energy harvester. Green hybrid power system based on TENG renders as a promising solution to the sustainable and reliable power supply for wearable/portable electronics. This review aims to describe current progress on green hybrid power system based on TENG. Both of the hybrid nanogenerator, hybridization of TENG and energy storage unit, integration of hybrid nanogenerator and energy storage unit were comprehensively reviewed. Research progress on multifunctionalization of green hybrid power system based on TENG is also disscussed. The green hybrid power system based on TENG which possesses excellent service behavior would break through the existing limitations and be the new generation of green power supply. The presented development trend and design guidelines will be beneficial to research of future green micro/nano-system, including micro-electromechanical systems, remote and mobile environmental systems, homeland security systems, and so on.

Analysis on the influence of cylinder efficiency on coal consumption of an ultra-supercritical double-reheat 1000 MW steam turbine unit

Taking an ultra-supercritical double-reheat 1000 MW steam turbine as an example, the influence rule of the ultra-high pressure cylinder, high pressure cylinder, intermediate pressure cylinder and low pressure cylinder on coal consumption of steam turbine under THA, 75%THA, 50%THA and 40%THA is analyzed. According to the data of cylinder efficiency on the heat consumption rate of steam turbine, combined with the design of the efficiency of the boiler and plant electricity rate, it is worth to work out the influence rule of cylinder efficiency on the power generation coal consumption and power supply coal consumption under THA condition. The conclusion shows that the influence of cylinder efficiency on coal consumption is basically linear. The efficiency of low pressure cylinder is the most sensitive, the efficiency of intermediate pressure cylinder is second, the efficiency of high pressure cylinder and ultra-high pressure cylinder has little effect on coal consumption. The conclusion can provide technical reference for energy-conservation diagnosis and management on the ultra-supercritical double-reheat 1000 MW steam turbine.

Проектирование, оптимизация и испытание высокоскоростного магнитоэлектрического генератора для электроснабжения микробеспилотных летательных аппаратов

Проектирование, оптимизация и испытание высокоскоростного магнитоэлектрического генератора для электроснабжения микробеспилотных летательных аппаратов

Wind and Solar Radiation Potential Assessment in Kano, Nigeria Using Weibull and Samani Models

A clean, source free, environmentally friendly and renewable source of energy such as wind and solar energy can be used for providing sustainable power supply to remedy an epileptic and unreliable power supply systems. For decades, electric power supply situation in Kano, Nigeria has been a major source of serious concern. The epileptic power supply has hindered the socio-economic growth industrialization and, subsequently, increase air pollution due to individual stand-alone diesel generators. Various government incentives and policies have little or no effect to improve the availability and reliability of the electric power. The aviation industries especially the Navigation and communication equipment required, apart from availability, a reliable power sources because of their sensitivity to reliable and safe Aircraft navigation. The need for an alternate renewable energy system (RES) of power supply away from the National grid and diesel generator is inevitable at Kano. This paper proposes an assessment of wind and solar energy potentialities at Kano in Nigeria using Weibull distribution methods and the Samani model to determine the wind features and estimate global solar radiation potentials respectively for power supply generation. A six years (2009-2014) monthly mean wind speed data measured at 10 m height was collected and extrapolated to 50 m height level for statistical analysis, while 22 years monthly solar radiation, temperature amplitude and relative humidity of the location were obtained from NASA web to calibrate, validate and evaluate the Samani model, ten years (2003-2012) maximum and minimum temperature were then used to predict the global solar radiation on horizontal surface of the location. The minimum Weibull average wind speed was found to be 8.60 m/s and the maximum average wind speed was 11.24 m/s while the minimum power density was 440.03 W/m2 and the highest was 947.26 W/m2 at the 10 m height level. The lowest average global solar radiation on the horizontal surface was 17.96 MJ/m2/d and highest average global solar radiation on the horizontal surface was 26.38 MJ/m2/d. The site has been found to have great potentials for wind and solar utility power generation capacity.

Research of Active Regulation for High-Stability Flat-Top Pulsed High Magnetic Field

With large energy storage and flexible control capabilities, pulse generator is an ideal power supply for flat-top magnetic fields. However, characteristics of the pulse generator, such as nonlinearity and time variance, are a limitation on improving flat-top stability. Based on the pulse generator power supply for the flat-top magnetic field at Wuhan National High Magnetic Field Center, this paper proposes an active regulator for the flat-top magnetic field. An optimal control strategy combining selective PI control and repetitive control is proposed to restrain the circulating current between the pulse generator and the active regulator. A 50 T/140 ms flat-top magnetic field with the ripple less than 100 ppm is achieved by applying an active regulator. In order to validate the effectiveness of the optimal control strategy for the high stability flat-top magnetic field with an active regulator, experimental data about the triggering angle of the rectifier are utilized in the simulation model; the result indicates that the circulating current between the pulse generator and the active regulator is suppressed to a great extent.

ENERGY EFFICIENT DESALINATOR

Objectives The aim of the research was the development of an ultrasonic generator of technological design with a wide frequency range of output voltage. Methods The prototype works were performed and the functional scheme of the multifrequency ultrasonic generator realised in the experimental sample was developed, as well as the design of an ultrasonic piezoceramic system capable of operating at two resonant frequencies of 22 and 44 kHz. Results Based on the feature analysis of the modern composite material structure and technologies for moulding products, it was found to be expedient to introduce ultrasonic impregnation into the technological process, which can ensure increased uniformity in filling the structure with a binder as well as greater homogeneity of physicomechanical characteristics. A schema for the ultrasonic generator built into the technological equipment is developed, providing the formation of harmonic signals with a frequency alternating from 20 to 60 kHz, and power adjustable from 100 to 500 W, which will allow the implementation of highperformance ultrasonic technologies for processing materials with a heterogeneous structure formed during the manufacturing process. The studies were carried out according to parametric optimisation of the converter taking into account the specific load types. A special feature of the generator's power supply is its versatility in terms of frequency and voltage ranges, as well as the required quality indicators of the energy generated. The generator allows the reference frequency to be programmed using a laptop and then fine-tuned from the control panel in resonance with the radiator with a resolution of 10 Hz directly. The built-in microprocessor allows the reference frequency entered from the laptop to be stored in the memory. Conclusion The use of multifrequency ultrasonic sources allows the acting parameters to be optimised for ultrasonic impregnation of fibre-reinforced composite materials as well as their finishing dimensional processing, depending on the density of the structure and the reinforcement scheme used.

Energy scheduling strategy for a photovoltaic/batteries bank/diesel generator power supply system for an off-grid house

A novel algorithm is proposed to control the overall energy produced by a photovoltaic/battery bank/diesel generator renewable energy system. A renewable energy system is used to supply an off-grid connected house in Sfax, Tunisia. The algorithm computes recurrently the battery depth of discharge and diesel consumption of the diesel generator and then forecasts the photovoltaic subsystem output power every two minutes ahead. The estimated power is computed using an auto-regressive moving average model associated with a Kalman filter. During each calculation loop, hybrid system energy scheduling is accomplished considering criteria that guarantee the maximum use of generated renewable energy, minimum diesel generator operational time, and full-load need satisfaction during the whole day. Numerical simulations for two typical sunny and cloudy days in Sfax, Tunisia, are conducted in order to validate the algorithm and to compare the performance of managed system behavior with that of a standard unmanaged system. It is shown that the proposed energy management system could save fuel consumption by as much as 11.27% in the sunny day and 9.17% in the cloudy day.

Trade-Offs between Economic and Environmental Optimization of the Forest Biomass Generation Supply Chain in Inner Mongolia, China

The utilization of forest residue to produce forest biomass energy can mitigate CO2 emissions and generate additional revenue for related eco-enterprises and farmers. In China, however, the benefit of this utilization is still in question because of high costs and CO2 emissions in the entire supply chain. In this paper, a multi-objective linear programming model (MLP) is employed to analyze the trade-offs between the economic and environmental benefits of all nodes within the forest biomass power generation supply chain. The MLP model is tested in the Mao Wu Su biomass Thermoelectric Company. The optimization results show that (1) the total cost and CO2 emissions are decreased by US$98.4 thousand and 60.6 thousand kg, respectively; 3750 thousand kg of waste-wood products is reduced and 3750 thousand kg of sandy shrub stubble residue is increased; (2) 64% of chipped sandy shrub residue is transported directly from the forestland to the power plant, 36% of non-chipped sandy shrub residue is transported from the forestland to the power plant via the chipping plant; (3) transportation and chipping play a significant role in the supply chain; and (4) the results of a sensitivity analysis show that the farmer’s average transportation distance should be 84.13 km and unit chipping cost should be $0.01022 thousand for the optimization supply cost and CO2 emissions. Finally, we suggest the following: (1) develop long-term cooperation with farmers; (2) buy chain-saws for regularly used farmers; (3) build several chipping plants in areas that are rich in sandy shrub.

Small gas-turbine units for the power industry: Ways for improving the efficiency and the scale of implementation

Small power units (<1 MW) see increasing application due to enhanced growth of the distributed power generation and smart power supply systems. They are usually used for feeding facilities whose connection to centralized networks involves certain problems of engineering or economical nature. Small power generation is based on a wide range of processes and primary sources, including renewable and local ones, such as nonconventional hydrocarbon fuel comprising associated gas, biogas, coalmine methane, etc. Characteristics of small gas-turbine units (GTU) that are most widely available on the world market are reviewed. The most promising lines for the development of the new generation of small GTUs are examined. Special emphasis is placed on the three lines selected for improving the efficiency of small GTUs: increasing the fuel efficiency, cutting down the maintenance cost, and integration with local or renewable power sources. It is demonstrated that, as to the specific fuel consumption, small GTUs of the new generation can have an efficiency 20–25% higher than those of the previous generation, require no maintenance between overhauls, and can be capable of efficient integration into intelligent electrical networks with power facilities operating on renewable or local power sources.

Hardware Design of a Small UAS Helicopter for Remote Sensing Operations

This paper presents the hardware design and integration process employed to develop an Unmanned Aircraft System (UAS) helicopter. The design process evolves from the bare airframe (without any electronics), to become a complete and advanced UAS platform for remote sensing applications. The improvements, design decisions and justifications are described throughout the paper. Two airframes have been used during the design and integration process: the AF25B model and the more advanced AF30 model, from the Copterworks company. The airframe engine reliability and fuel economy have been improved by adding an Electronic Fuel Injection (EFI) and Capacitor Discharge Ignition (CDI), both managed by an Engine Control Unit (ECU). On-board power supply generation and regulation have also been designed and validated. Finally, the integration process incorporates on-board mission computation to improve the concept of operation in remote sensing applications. Several flight tests have been performed to verify the reliability of the whole system. The flight test results demonstrate the correct process of integration and the feasibility of the UAS.