Annual Energy Outlook 2008 With Projections to 2030

ライブラリー Annual Energy Outlook 2000

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In the last few years, the application of Model Predictive Control (MPC) for energy management in buildings has received significant attention from the research community. MPC is becoming more and more viable because of the increase in computational power of building automation systems and the availability of a significant amount of monitored building data. MPC has found successful implementation in building thermal regulation, fully exploiting the potential of building thermal mass. Moreover, MPC has been positively applied to active energy storage systems, as well as to the optimal management of on-site renewable energy sources. MPC also opens up several opportunities for enhancing energy efficiency in the operation of Heating Ventilation and Air Conditioning (HVAC) systems because of its ability to consider constraints, prediction of disturbances and multiple conflicting objectives, such as indoor thermal comfort and building energy demand. Despite the application of MPC algorithms in building control has been thoroughly investigated in various works, a unified framework that fully describes and formulates the implementation is still lacking. Firstly, this work introduces a common dictionary and taxonomy that gives a common ground to all the engineering disciplines involved in building design and control. Secondly the main scope of this paper is to define the MPC formulation framework and critically discuss the outcomes of different existing MPC algorithms for building and HVAC system management. The potential benefits of the application of MPC in improving energy efficiency in buildings were highlighted.

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Model Predictive Control (MPC) for Enhancing Building and HVAC System Energy Efficiency: Problem Formulation, Applications and Opportunities

This paper investigates heat pump systems in smart grids, focussing on fields of application and control approaches that have emerged in academic literature. Based on a review of published literatu ...

https://zenodo.org/record/895978/files/article.pdf

On heat pumps in smart grids: A review

This paper deals with the design optimization of iron-cored linear motor with trapezoidal permanent magnets (PMs) configurations. Such motor is a short-stroke, single-phase tubular linear permanent magnet motor (TLPMM). The motor equipped with a quasi-Halbach magnetized moving-magnet armature and stator with a single slot and a single coil. The predicted magnetic field distribution in the airgap, flux-linkage and winding inductance of the proposed design, are already presented in a previous papers. The design optimization of the proposed TLPMM for the leading design parameters has been conducted. The optimal values of the axial length of the magnet at the center to the pole-pitch ratio and the split ratio are found to be 0.64 and 0.52. The efficiencies at these optimal values are 93.13 % and 93.8 %, respectively. Also, the angle of the trapezoidal PMs is optimized, and it is found to be equal 60°. Meanwhile, the losses of the motor, such as iron loss and copper loss are predicted and analyzed. The finite-element analysis (FEA) was successfully implemented for this study.

Optimization of iron-cored linear motor with trapezoidal magnet using finite-element analysis

The application of the Phasor Measurement Unit (PMU) in the power system is expanding day by day since it provides a higher reliability through fast symmetrically monitoring and protection and assists in controlling power systems. For power systems, islanding is a significant event due to its hazardous consequences. To detect islanding events, several schemes have been previously proposed but inappropriate threshold setting, higher computational time, and false tripping are the main limitations. In addition, differentiating between real island events and transient faults is another limitation. However, appropriate threshold setting plays a considerable part in detecting the island event, which is also important to differentiate between real and non-island events. Phasor Measurement Unit can assist in islanding detection, but it can generate 30 samples/s, so there is always the possibility of making particular period data disappear. The principal contribution of this review article is its detailed discussion of real-time symmetrical PMU data and it further presents different PMU data analytic techniques and the proposed schemes for the islanding detection system. An appropriate methodology tried to understand how to incorporate missing PMU data techniques along with the islanding detection system to ensure the higher reliability of the network.

/pdf/review-of-the-techniques-of-the-data-analytics-and-islanding-24qt309z.pdf

Review of the Techniques of the Data Analytics and Islanding Detection of Distribution Systems Using Phasor Measurement Unit Data

Comparison of Power System Harmonic Prediction

The volatile fossil fuel price currently creates an opportunity for the development of alternative approaches in electricity generation. Comprehensive and concerted efforts are focused at developing solar electricity generating system (SEGS). One of the challenges faced by SEGS is the apparent trajectory of the sun. Often, SEGS designers use standard testing conditions, whereby the level of solar insolation is taken to be a constant value of 1000W/m2. The only value of solar insolation that is taken to be constant is known as solar constant, which is approximately 1353W/m2. Solar constant is the solar insolation received outside the earth's atmosphere. This value drops significantly as the solar radiation passes through the atmosphere, where the typical range is between 150 W/m2 and 1000W/m2. The reducing intensity of solar insolation is also due to the apparent trajectory of the sun. The sun's path changes daily, and in this project, a novel design of the sun tracker has been tested and is able to do two-axis tracking for photovoltaic based SEGS.

Development of two-axis sun tracking system

Medium voltage (MV) crosslink polyethylene (XLPE) power cables are extensively utilized in power distribution networks throughout the world. Reliable power delivery depends on the condition of the power cable and distribution system network components. Failure of power cables can cause loss in terms of power outages, capital, and human resources. This is a prime area for research. Degradation of the physical properties of the insulation over time is the usual cause of power cable failure. Factors responsible for XLPE cable degradation include but are not limited to mechanical, electrical and chemical stresses, flaws in manufacturing, and conditions in the environment. The aforesaid degradation factors cause water trees, electrical trees and partial discharge, and finally result into power cable failure. The nonlinear nature of a water tree results in harmonic generation in the AC loss current. The magnitude of the higher harmonics thus generated, depends on the amount of nonlinearity, therefore, amplitude and phase angel of the third harmonic current can be utilized to detect and quantify the degradation level. The main objective of this papers is to present a brief review on methods introduced in literature to utilize the third harmonic current as a diagnostic tool to identify and quantify the power cable degradation.

Nursyarizal Mohd Nor

Papers

Optimization of iron-cored linear motor with trapezoidal magnet using finite-element analysis

Review of the Techniques of the Data Analytics and Islanding Detection of Distribution Systems Using Phasor Measurement Unit Data

Comparison of Power System Harmonic Prediction

Development of two-axis sun tracking system

Review of third harmonic current characteristic based diagnostic methods of medium voltage power cable insulation