Power Deficit Research Articles

Futuristic Approach of Utilisation of Hydropower in India

Hydro power is a renewable source of energy used in most parts of the world. India is very rich in hydropower potential. It is the only clean and renewable source today making significance in the world of power production. With the rising economic growth and income level India is bound to have higher demand for electricity supply. India presently has an installed power generation capacity of 284,303MW (2015) inclusive of Hydropower which is 42,623MW(2015) .The situation is highlighted by the peak power deficit—shortfall in supply of power when the demand is maximum—was 5.2% in year 2013-14.With the fast depleting natural resources, it becomes mandatory that we increase the use of Renewable Resources for Power generation .When Thermal power in 2007 was 64% of the total generation and Hydro power was 26% and in 2015 instead of the thermal graph falling and Hydro power rising we see a different picture . In 2015 thermal has grown to 70% and hydro has fallen to 15%.Hydropower is such a good source for power why do we see the graph falling every year?? The amount of land submergence required for large Dams is the biggest concern where the Forest Act and the Environment Act also offer rigidity towards the same. Relative to so much submergence arises another major problem of Rehabilitation and Resettlement .Climatic changes and other negative effects of fossil fuel for power generation are growing concerns and therefore driving the expansion of hydropower around the world. The Reservoir based hydropower projects have also come under criticism due to carbon dioxide and methane emissions beyond acceptable limits. Ecological and many more issues that are preventing Hydro power as becoming the major source of electricity generation. In this paper we will review the major issues faced due to large hydropower plants and why they are not termed as Renewable sources.

Design of Power, Propulsion, and Thermal Sub-Systems for a 3U CubeSat Measuring Earth’s Radiation Imbalance

The paper presents the development of the power, propulsion, and thermal systems for a 3U CubeSat orbiting Earth at a radius of 600 km measuring the radiation imbalance using the RAVAN (Radiometer Assessment using Vertically Aligned NanoTubes) payload developed by NASA (National Aeronautics and Space Administration). The propulsion system was selected as a Mars-Space PPTCUP -Pulsed Plasma Thruster for CubeSat Propulsion, micro-pulsed plasma thruster with satisfactory capability to provide enough impulse to overcome the generated force due to drag to maintain an altitude of 600 km and bring the CubeSat down to a graveyard orbit of 513 km. Thermal analysis for hot case found that the integration of a black high-emissivity paint and MLI was required to prevent excessive heating within the structure. Furthermore, the power system analysis successfully defined electrical consumption scenarios for the CubeSat’s 600 km orbit. The analysis concluded that a singular 7 W solar panel mounted on a sun-facing side of the CubeSat using a sun sensor could satisfactorily power the electrical system throughout the hot phase and charge the craft’s battery enough to ensure constant electrical operation during the cold phase, even with the additional integration of an active thermal heater. However, when the inevitable end-of-life degradation of the solar cell was factored into the analysis, an approximate power deficit of 2 kJ was found. This was supplemented by additional solar cell integrated into the antenna housing face.

Study of wind farm control potential based on SCADA data

In this work, a control-oriented wind farm model is validated against SCADA data from a typical on-shore wind farm, without additional instrumentation available. The comparison of model-predicted and measured power deficits due to wake impingement shows good agreement. Furthermore, the model is used to compute optimum yaw misalignments for yaw-induced wake steering, leading to an estimated 1.7% increase in annual energy production by mitigation of wake losses. Results show that wake steering based on standard SCADA data, which is usually available in operational wind farms, has promising potential for open-loop model-based wind farm control.

Primordial perturbations with pre-inflationary bounce

Based on the effective field theory (EFT) of nonsingular cosmologies, we build a stable model, without the ghost and gradient instabilities, of bounce inflation (inflation is preceded by a cosmological bounce). We perform a full simulation for the evolution of scalar perturbation, and find that the perturbation spectrum has a large-scale suppression (as expected), which is consistent with the power deficit of the cosmic microwave background (CMB) TT-spectrum at low multipoles, but unexpectedly, it also shows itself one marked lower valley, which actually provides a better fit to the dip at multipole $l\sim 20$. The depth of valley is relevant with the physics around the bounce scale, which is model-dependent.

Impaired Midline Theta Power and Connectivity During Proactive Cognitive Control in Schizophrenia

BackgroundDisrupted proactive cognitive control, a form of early selection and active goal maintenance, is hypothesized to underlie the broad cognitive deficits observed in patients with schizophrenia (SPs). Current research suggests that the disrupted activation within and connectivity between regions of the cognitive control network contribute to disrupted proactive cognitive control; however, no study has examined these mechanisms using an AX Continuous Performance Test task in schizophrenia. MethodsTwenty-six SPs (17 male subjects; mean age 34.46 ± 8.77 years) and 28 healthy control participants (HCs; 16 male subjects; mean age 31.43 ± 7.23 years) underwent an electroencephalogram while performing the AX Continuous Performance Test. To examine the extent of activation and level of connectivity within the cognitive control network, power, intertrial phase clustering, and intersite phase clustering metrics were calculated and analyzed. ResultsSPs exhibited expected general decrements in behavioral performance relative to HCs and a more selective deficit in conditions requiring proactive cognitive control. Additionally, SPs exhibited deficits in midline theta power and connectivity during proactive cognitive control trials. Specifically, HCs exhibited significantly greater theta power for B cues relative to A cues, whereas SPs exhibited no significant differences between A- and B-cue theta power. Additionally, differential theta connectivity patterns were observed in SPs and HCs. Behavioral measures of proactive cognitive control predicted functional outcomes in SPs. ConclusionsThis study suggests that low-frequency midline theta activity is selectively disrupted during proactive cognitive control in SPs. The disrupted midline theta activity may reflect a failure of SPs to proactively recruit cognitive control processes.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision 2018: Using the Evidence to Guide Physical Therapist Practice

Midportion Achilles tendinopathy is a relatively common, overuse, lower extremity soft tissue injury for individuals who are active and participate in sports. The clinical practice guideline published in the May 2018 issue of JOSPT, titled "Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision 2018," can help physical therapists engage in evidence-informed practice and reduce unnecessary clinical variation. J Orthop Sports Phys Ther 2018;48(5):425-426. doi:10.2519/jospt.2018.0505.

Kenya's lessons from two decades of experience with independent power producers

Adequate, secure, and competitively priced electricity is vital for powering economic growth and development. Privately funded, independent power producers (IPPs) are now making an important contribution to meeting overall power needs in developing countries, including in Africa. Our aim in this article is to explore what may be learned from Kenya's experience with IPPs and what lessons might be applied to other developing countries. We consider how Kenya's IPPs measure up to their public counterparts in terms of reliability and costs and possibilities for scale-up. Kenya's two decades of experience with power sector reform and IPPs makes it possible to compare changing policies, sector unbundling, regulatory frameworks, planning, and investment over a relatively long period. Kenya is also host to IPPs with different technology bases, which allow for an evaluation of their relative costs and reliability. Finally, the mix of directly negotiated and competitively bid projects facilitates a comparison of procurement practices. While power sector reform in Kenya created an enabling environment for IPPs, probably more important was the development of effective planning, tendering, and contracting capabilities, which attracted investment at competitive prices. The challenge for Kenya and other developing countries is to maintain and sustain these capabilities within clear policies that provide regular opportunities for the private sector to contribute to meeting power deficits.

Performance of solar PV-fuel cell (FC) hybrid system for stand-alone applications

This paper presents the performance of a hybrid solar PV/ Fuel Cell/ FC system with a PMDC motor load. The hybrid system supplies power to the DC motor during day and night. In order to obtain continuous supply to the load, a control strategy is implemented in the system. By using this control strategy, the solar PV and the fuel cell supply the voltage to the load by getting constant supply from the DC link during day and night. The DC-DC interleaved soft switching boost converter (ISSBC) with Incremental conductance maximum power point tracking technique (INC MPPT) is used to maintain constant DC link voltage. When the power deficit happens in the solar PV, the hydrogen stored in the tank is used by the fuel cell stack and supplies power to the load. The entire system is modeled and the performance of the hybrid system is analyzed in MATLAB/Simulink environment.

Effect of gabapentin on sleep and delta and theta EEG power in adult rats exposed to chronic intermittent ethanol vapor and protracted withdrawal during adolescence.

Adolescents and young adults with alcohol problems may also have sleep difficulties. However, whether these sleep problems are a result of a history of drinking or arise due to other comorbid disorders is difficult to disentangle in human studies. Additionally, the mechanisms underlying adolescent alcohol-induced sleep disturbances and potential targets for therapy also remain under-investigated. Recent clinical trials have demonstrated that the anticonvulsant and analgesic drug gabapentin may have therapeutic value in normalizing sleep quality in adult recovering alcoholics, yet its potential for the treatment of adolescent sleep disturbances has not been investigated. This study sought to evaluate the effects of a history of 5weeks of chronic intermittent ethanol vapor exposure, administered during adolescence (AIE), on EEG sleep, in young adult rats (n = 29). The ability of two doses of gabapentin (30, 120mg/kg) to modify sleep and slow wave activity were also investigated in these young adult rats exposed to alcohol vapor during adolescence. Adolescent vapor exposure in the rat was found to result in deficits in delta (1-4Hz) and theta (4-8Hz) power during slow wave sleep. Administration of gabapentin caused a "normalization" of the delta power deficits but did not affect theta power. This report suggests that the potential mechanisms and therapeutic targets for sleep disturbance associated with adolescent alcohol exposure can be studied in preclinical models and that gabapentin may show partial efficacy in ameliorating these sleep deficits.

Autonomous power management for interlinked AC-DC microgrids

The existing power management schemes for interlinked AC-DC microgrids have several operational drawbacks. Some of the existing control schemes are designed with the main objective of sharing power among the interlinked microgrids based on their loading conditions, while other schemes regulate the voltage of the interlinked microgrids without considering the specific loading conditions. However, the existing schemes cannot achieve both objectives efficiently. To address these issues, an autonomous power management scheme is proposed, which explicitly considers the specific loading condition of the DC microgrid before importing power from the interlinked AC microgrid. This strategy enables voltage regulation in the DC microgrid, and also reduces the number of converters in operation. The proposed scheme is fully autonomous while it retains the plug-nplay features for generators and tie-converters. The performance of the proposed control scheme has been validated under different operating scenarios. The results demonstrate the effectiveness of the proposed scheme in managing the power deficit in the DC microgrid efficiently and autonomously while maintaining the better voltage regulation in the DC microgrid.

Optimization of energy management and conversion in the water systems based on evolutionary algorithms

In this article, an application of weed optimization algorithm (WOA) for reservoir operation was proposed. In addition, genetic algorithm (GA) and particle swarm optimization algorithm (PSOA) have been used as successful algorithms in such engineering application for optimizations in order to introduce a comprehensive comparison analysis with the results of WOA. Two case studies were considered in this research. The aim of the first case study was to minimize irrigation water deficits for Aydoughmoush dam in Iran. Results showed that average solution of the operation rule of the WOA is close to the global solution and that reliability index and resiliency index for water supply, based on WOA, are higher than the GA and PSOA. Also, the operation rule achieved by the WOA has well-supplied water to match the water demands for the operation period (1991–2000). The second case study was related to minimize the electricity power deficits in Karun-4 reservoir. In fact, the water should be released such that the electricity power generation is maximized or the electricity power deficit should be minimized. Results showed that the operation rule for the water achieved by the WOA produces more electrical power than GA and PSOA. Furthermore, the average solution accomplished by WOA is very close to the global solution. Different indexes were used for evaluating the proposed methods, namely reliability index, vulnerability index, and resiliency index. For the first case study, the proposed WOA could achieve 98% reliability which is outperformed the other GA and PSOA methods. On the other hand, for the second case study, the proposed WOA method could attain electricity power 12 and 15% more than the one generated while using the GA and PSOA methods. Thus, WOA has high potential to be applied for achieving optimal operation rule for dam and reservoir operation and better water resources management and plan.

Distributed load shedding for microgrid with compensation support via wireless network

Due to the limited generation and finite inertia, microgrid suffers from the large frequency and voltage deviation which can lead to system collapse. Thus, reliable load shedding to keep frequency stable is required. Wireless network, benefiting from the high flexibility and low deployment cost, is considered as a promising technology for fine-grained management. In this paper, for balancing the supply-demand and reducing the load-shedding amount, a distributed load shedding solution via wireless network is proposed. Firstly, active power coordination of different priority loads is formulated as an optimisation problem. To solve it, a distributed load shedding algorithm based on subgradient method (DLSS) is developed for gradually shedding loads. Using this method, power compensation can be utilised and has more time to lower the power deficit so as to reduce the load-shedding amount. Secondly, to increase the response rate and enhance the reliability of our method, a multicast metropolis schedule based on TDMA (MMST) is developed. In this protocol, time slots are dedicatedly allocated and a checking and retransmission mechanism is utilised. Finally, the proposed solution is evaluated by NS3-Matlab co-simulator. The numerical results demonstrate the feasibility and effectiveness of our solution.

A new demand response algorithm for solar PV intermittency management

This paper presents a new algorithm for managing solar PV intermittency in green buildings using demand response management (DRM) technique. The proposed DRM algorithm utilizes the building air conditioning and mechanical ventilation (ACMV) system to dynamically compensate for the deficit of power generated by solar PV system from its rated capacity. For example, the developed solution will reduce the load demand of the ACMV system equal to the drop of solar generation by controlling the speed of the fan. This will ensure that the amount of power supplied by the grid to the building will remain the same (as before the drop of solar generation) and thus no impact on the grid stability. However, since ACMV system is directly linked to building occupant comfort/health, the proposed solution will also include energy storage management and priority-based load shedding programs to provide support when room temperature (air conditioning) or CO level (ventilation) is above regulatory limit. A thermal model for building temperature variation is developed to test and analyze the proposed algorithm to dynamically manage solar PV fluctuation.

Comprehensive Study on Different Possible Operations of Multiple Grid Connected Microgrids

This paper proposes an efficient strategy for control of multiple grid connected microgrids (MGs) through converters, to improve network management during normal, islanding, and fault conditions. In normal condition, the converters control the bidirectional power flow between the MGs (downstream) and the main network (upstream). When the upstream is disconnected from downstream, if one of the MGs cannot handle its local loads, the deficit of power is provided by the other MGs. Transferred powers of the MGs are controlled regarding power quality (PQ) preserving criteria of the network. If PQ in a point of common coupling of an MG degrades, its converter goes into semi-isolated mode. Furthermore, in case of fault occurrence in the upstream, the converters limit fault current contribution of the MGs, in order to preserve the MGs PQ. However, in case of fault occurrence in the MG, the converters are bypassed by the relevant static switches. Therefore, short circuit current contribution of the upstream will be maximized to improve the MGs PQ. This strategy can also overcome the problems related to the system short circuit capacity increment in case of a newly added distributed generation unit, such as loss of the over current relays coordination.

Simple moving average based capacity optimization for VRLA battery in PV power smoothing application using MCTLBO

Rapid depletion of fossil fuel reserves and alarming increase of environmental pollution shift the researchers’ attention towards renewable energy sources technologies like solar photovoltaic (PV). But solar radiation being affected by natural factors, result in uncertain power generation which leads to lower power system reliability. This paper proposes a smoothing strategy of generated PV power using gelled electrolyte valve regulated lead acid (VRLA) type battery energy storage system (BESS). The BESS stores the excess energy and releases it to meet the load demand in case of power surplus and deficit, respectively. The IEEE-RBTS is considered as the basic system for the study. But using large BESS incur humungous cost. Hence Multi-course teaching learning based multi-objective optimization technique (MCTLBO) is utilized to find out the optimal size of the PV panel, the BESS and the smoothening duration. Here, the objectives are to obtain minimum financial loss due to power outage as well as minimum BESS life cycle cost. MCTLBO is proposed here to improve the performance of the traditional teaching learning based optimization technique and it shows promising results. Factors affecting the power output of the PV panels are also considered here. The simulation is performed considering real time solar irradiance and temperature data of a city located on the eastern coast of India and the results obtained are both technically and economically viable in Indian context.

Improved UFLS with consideration of power deficit during shedding process and flexible load selection

This study presents an improved under-frequency load shedding (UFLS) scheme that can detect power deficit during the shedding process and accordingly adjust the amount of load shedding. This is achieved by continuous monitoring of the overshooting signal of the second frequency derivative of the centre of inertia. Once detected, an equivalent system inertia constant is estimated in order to quantify the new power deficit. The scheme is also equipped with an optimisation algorithm to determine the best combination of loads that is close to the amount of power deficit, which minimises frequency overshoot/undershoot. The optimisation technique selected for this work is based on particle swarm optimisation. The performance of the proposed UFLS scheme was validated using a modified IEEE 33 bus with two mini-hydro generators and one full converter wind turbine. The system and the proposed UFLS was modelled and simulated in PSCAD/EMTDC software. The results confirmed that the proposed scheme is capable of shedding loads with minimum undershoot/overshoot, and detect and estimate a new power deficit during load shedding. The results reported by the proposed scheme proved to be significantly better than those reported by conventional and adaptive load shedding schemes.

Optimization of solar energy conversion power plant parameters

Autonomous power supplies based on solar batteries (SB) and wind generators are increasingly used. The structure of such systems, in addition to the SB itself, includes a re-chargeable battery (AB), a cable network, a load switch and a charge controller that performs, with an excess of the SB power, the functions of maintaining a given charg-ing current or charging voltage AB, and power deficit SB providing a mode of selection of maximal power from SB. In this paper, a mathematical model of such a system and its elements is presented.

Potential Analysis of Ex-Coal Mining Land As Pumped Storage Hydro Powerplant In Kutai Kartanegara, East Kalimantan

The growth of electricity demand will increase 56.8% in 10 years. Meanwhile, the fulfillment of electricity in Indonesia is dominated by coal. The amount of electricity growth has not balanced yet by the amount of electricity supply. It causes the electricity deficit in some areas, especially at the peak load period. One of the areas that often have electrical power deficit is East Kalimantan, although the province is one of the biggest coal mining areas in Indonesia. The mining activities give several impacts in environmental damages especially in the ex-coal mining land which has not been well managed. The impact includes an irreversible change of landscape and huge craters caused by open mining activities. In this study, an analysis is conducted for utilization of ex-coal mining land in Kutai Kartanegara as a reservoir of energy storage system type Pumped Hydroelectric Storage (PSH). The analysis provides a comparison of three variations of the piping line system. The study uses the spatial data in the form of Digital Elevation Model (DEM) to calculate the time of starting operation system, expected generated energy, required energy for power plant operation and the efficiency of the system. This study compares some criteria based on three variations of the piping line system and the effect on the efficiency of the system.

Overcoming Solar PV Intermittency using Demand Response Management in Buildings

Singapore’s National Climate Change Policy is aimed to make energy usage in Singapore more efficient, reduce pollution and expand the nation’s green spaces. Part of the plan is to promote the integration of solar photovoltaics (PVs) on rooftops of high-rise HDB residential and commercial buildings. This initiative contributed to the significant growth in the integration of solar PV systems in the last few years. However, large-scale integration of solar PVs will put at risk the reliability and stability of Singapore’s power system due to its intermittent nature. The intermittency problem of solar PV, typically in the range of minutes, will become very significant in Singapore as the installations of PV systems continue to increase. Conventionally, large energy storage systems are deployed as an energy buffer to compensate for the deficit or surplus of power supplied by solar PV systems. However, the high capital and maintenance costs as well as large space requirement for energy storage systems makes this an unfavorable option for building owners. This paper proposes a solution that utilizes the centrifugal fans in building air conditioning and mechanical ventilation (ACMV) system to dynamically compensate for the deficit or surplus of power supplied by solar PVs. For example, the developed solution will reduce the load demand of fans in the ACMV system equal to the drop of solar generation by controlling the speed of the fan. This will ensure that the amount of power supplied by the grid to the building will remain the same (as before the drop of solar generation) and thus no impact on the grid stability. However, since ACMV system is directly linked to building occupant comfort/health, the proposed solution will also include battery management and priority-based load shedding programs to provide support when room temperature (air conditioning) or CO level (ventilation) is above regulatory limit.

Planck intermediate results

The six parameters of the standard ΛCDM model have best-fit values derived from the Planck temperature power spectrum that are shifted somewhat from the best-fit values derived from WMAP data. These shifts are driven by features in the Planck temperature power spectrum at angular scales that had never before been measured to cosmic-variance level precision. We have investigated these shifts to determine whether they are within the range of expectation and to understand their origin in the data. Taking our parameter set to be the optical depth of the reionized intergalactic medium τ, the baryon density ωb, the matter density ωm, the angular size of the sound horizon θ∗, the spectral index of the primordial power spectrum, ns, and Ase− 2τ (where As is the amplitude of the primordial power spectrum), we have examined the change in best-fit values between a WMAP-like large angular-scale data set (with multipole moment ℓ < 800 in the Planck temperature power spectrum) and an all angular-scale data set (ℓ < 2500Planck temperature power spectrum), each with a prior on τ of 0.07 ± 0.02. We find that the shifts, in units of the 1σ expected dispersion for each parameter, are { Δτ,ΔAse− 2τ,Δns,Δωm,Δωb,Δθ∗ } = { −1.7,−2.2,1.2,−2.0,1.1,0.9 }, with a χ2 value of 8.0. We find that this χ2 value is exceeded in 15% of our simulated data sets, and that a parameter deviates by more than 2.2σ in 9% of simulated data sets, meaning that the shifts are not unusually large. Comparing ℓ < 800 instead to ℓ> 800, or splitting at a different multipole, yields similar results. We examined the ℓ < 800 model residuals in the ℓ> 800 power spectrum data and find that the features there that drive these shifts are a set of oscillations across a broad range of angular scales. Although they partly appear similar to the effects of enhanced gravitational lensing, the shifts in ΛCDM parameters that arise in response to these features correspond to model spectrum changes that are predominantly due to non-lensing effects; the only exception is τ, which, at fixed Ase− 2τ, affects the ℓ> 800 temperature power spectrum solely through the associated change in As and the impact of that on the lensing potential power spectrum. We also ask, “what is it about the power spectrum at ℓ < 800 that leads to somewhat different best-fit parameters than come from the full ℓ range?” We find that if we discard the data at ℓ < 30, where there is a roughly 2σ downward fluctuation in power relative to the model that best fits the full ℓ range, the ℓ < 800 best-fit parameters shift significantly towards the ℓ < 2500 best-fit parameters. In contrast, including ℓ < 30, this previously noted “low-ℓ deficit” drives ns up and impacts parameters correlated with ns, such as ωm and H0. As expected, the ℓ < 30 data have a much greater impact on the ℓ < 800 best fit than on the ℓ < 2500 best fit. So although the shifts are not very significant, we find that they can be understood through the combined effects of an oscillatory-like set of high-ℓ residuals and the deficit in low-ℓ power, excursions consistent with sample variance that happen to map onto changes in cosmological parameters. Finally, we examine agreement between PlanckTT data and two other CMB data sets, namely the Planck lensing reconstruction and the TT power spectrum measured by the South Pole Telescope, again finding a lack of convincing evidence of any significant deviations in parameters, suggesting that current CMB data sets give an internally consistent picture of the ΛCDM model.