scholarly journals Multi-Step Energy Demand and Generation Forecasting with Confidence Used for Specification-Free Aggregate Demand Optimization

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3162
Author(s):  
Nikolaos Kolokas ◽  
Dimosthenis Ioannidis ◽  
Dimitrios Tzovaras

Energy demand and generation are common variables that need to be forecast in recent years, due to the necessity for energy self-consumption via storage and Demand Side Management. This work studies multi-step time series forecasting models for energy with confidence intervals for each time point, accompanied by a demand optimization algorithm, for energy management in partly or completely isolated islands. Particularly, the forecasting is performed via numerous traditional and contemporary machine learning regression models, which receive as input past energy data and weather forecasts. During pre-processing, the historical data are grouped into sets of months and days of week based on clustering models, and a separate regression model is automatically selected for each of them, as well as for each forecasting horizon. Furthermore, the multi-criteria optimization algorithm is implemented for demand scheduling with load shifting, assuming that, at each time point, demand is within its confidence interval resulting from the forecasting algorithm. Both clustering and multiple model training proved to be beneficial to forecasting compared to traditional training. The Normalized Root Mean Square Error of the forecasting models ranged approximately from 0.17 to 0.71, depending on the forecasting difficulty. It also appeared that the optimization algorithm can simultaneously increase renewable penetration and achieve load peak shaving, while also saving consumption cost in one of the tested islands. The global improvement estimation of the optimization algorithm ranged approximately from 5% to 38%, depending on the flexibility of the demand patterns.

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 352
Author(s):  
Saad Ullah Khan ◽  
Khawaja Khalid Mehmood ◽  
Zunaib Maqsood Haider ◽  
Muhammad Kashif Rafique ◽  
Muhammad Omer Khan ◽  
...  

In this paper, a coordination method of multiple electric vehicle (EV) aggregators has been devised to flatten the system load profile. The proposed scheme tends to reduce the peak demand by discharging EVs and fills the valley gap through EV charging in the off-peak period. Upper level fair proportional power distribution to the EV aggregators is exercised by the system operator which provides coordination among the aggregators based on their aggregated energy demand or capacity. The lower level min max objective function is implemented at each aggregator to distribute power to the EVs. Each aggregator ensures that the EV customers’ driving requirements are not relinquished in spite of their employment to support the grid. The scheme has been tested on IEEE 13-node distribution system and an actual distribution system situated in Seoul, Republic of Korea whilst utilizing actual EV mobility data. The results show that the system load profile is smoothed by the coordination of aggregators under peak shaving and valley filling goals. Also, the EVs are fully charged before departure while maintaining a minimum energy for emergency travel.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Ali Hatamizadeh ◽  
Yuanping Song ◽  
Jonathan B. Hopkins

We introduce a new computational tool called the Boundary Learning Optimization Tool (BLOT) that identifies the boundaries of the performance capabilities achieved by general flexure system topologies if their geometric parameters are allowed to vary from their smallest allowable feature sizes to their largest geometrically compatible feature sizes for given constituent materials. The boundaries generated by the BLOT fully define the design spaces of flexure systems and allow designers to visually identify which geometric versions of their synthesized topologies best achieve desired combinations of performance capabilities. The BLOT was created as a complementary tool to the freedom and constraint topologies (FACT) synthesis approach in that the BLOT is intended to optimize the geometry of the flexure topologies synthesized using the FACT approach. The BLOT trains artificial neural networks to create models of parameterized flexure topologies using numerically generated performance solutions from different design instantiations of those topologies. These models are then used by an optimization algorithm to plot the desired topology’s performance boundary. The model-training and boundary-plotting processes iterate using additional numerically generated solutions from each updated boundary generated until the final boundary is guaranteed to be accurate within any average error set by the user. A FACT-synthesized flexure topology is optimized using the BLOT as a simple case study.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zongxi Qu ◽  
Kequan Zhang ◽  
Jianzhou Wang ◽  
Wenyu Zhang ◽  
Wennan Leng

As a type of clean and renewable energy, the superiority of wind power has increasingly captured the world’s attention. Reliable and precise wind speed prediction is vital for wind power generation systems. Thus, a more effective and precise prediction model is essentially needed in the field of wind speed forecasting. Most previous forecasting models could adapt to various wind speed series data; however, these models ignored the importance of the data preprocessing and model parameter optimization. In view of its importance, a novel hybrid ensemble learning paradigm is proposed. In this model, the original wind speed data is firstly divided into a finite set of signal components by ensemble empirical mode decomposition, and then each signal is predicted by several artificial intelligence models with optimized parameters by using the fruit fly optimization algorithm and the final prediction values were obtained by reconstructing the refined series. To estimate the forecasting ability of the proposed model, 15 min wind speed data for wind farms in the coastal areas of China was performed to forecast as a case study. The empirical results show that the proposed hybrid model is superior to some existing traditional forecasting models regarding forecast performance.


2016 ◽  
Vol 10 (4) ◽  
pp. 576-593
Author(s):  
Hesam Nazari ◽  
Aliyeh Kazemi

Purpose This paper aims to select the best scenario for energy demand forecast of residential and commercial sectors in Iran by using particle swarm optimization algorithm. Design/methodology/approach In this study, using variables affecting energy demand of residential and commercial sectors in Iran, the future status of energy demand in these sectors is predicted. Using the particle swarm optimization algorithm, both linear and exponential forms of energy demand equations were studied under 72 different scenarios with various variables. The data from 1968 to 2011 were applied for model development and the appropriate scenario choice. Findings An exponential model with inputs including total value added minus that of the oil sector, value of made buildings, total number of households and consumer energy price index is the most suitable model. Finally, energy demand of residential and commercial sectors is estimated up to the year 2032. Results show that the energy demand of the sectors will achieve a level of about 1,718 million barrels of oil equivalent per year by 2032. Originality/value To the best of our knowledge in this study a suitable model is selected for energy demand forecast of residential and commercial sectors by evaluation of various models with different variables as inputs.


2018 ◽  
Vol 45 ◽  
pp. 00037
Author(s):  
Magdalena Krzywda ◽  
Jakub Jurasz ◽  
Jerzy Mikulik

The use of electric vehicles and photovoltaics is perceived as a viable option to reduce the human impact on the natural environment. This paper investigates the opportunity of managing a fleet of EVs along with PV installation in such a manner that shaves the peak load in an office building. The simulation used hourly load data representative for a small office building located in Cracow (Poland). For the same location hourly irradiation data was obtained. A deterministic model was created and implemented in MS Excel software. The study showed that 30 kW installed capacity in photovoltaics can reduce the observed peak load by 36% (from 19.8 kW to 14.52 kW) in a building consuming on an annual basis 54.7 MWh of electricity. Additionally, an appropriate management of the charging process of electric vehicles can increase the energy from photovoltaics self-consumption and level the observed energy demand in normal office building operating hours.


2021 ◽  
pp. 1-10
Author(s):  
Ceyda Tanyolaç Bilgiç ◽  
Boğaç Bilgiç ◽  
Ferhan Çebi

It is significant that the forecasting models give the closest result to the true value. Forecasting models are widespread in the literature. The grey model gives successful results with limited data. The existing Triangular Fuzzy Grey Model (TFGM (1,1)) in the literature is very useful in that it gives the maximum, minimum and average value directly in the data. A novel combined forecasting model named, Moth Flame Optimization Algorithm optimization of Triangular Fuzzy Grey Model, MFO-TFGM (1,1), is presented in this study. The existing TFGM (1,1) model parameters are optimized by a new nature- inspired heuristic algorithm named Moth-Flame Optimization algorithm which is inspired by the moths flying path. Unlike the studies in the literature, in order to improve the forecasting accuracy, six parameters (λL, λM, λR, α, β and γ) were optimized. After the steps of the model is presented, a forecasting implementation has been made with the proposed model. Turkey’s hourly electricity consumption data is utilized to show the success of the prediction model. Prediction results of proposed model is compared with TFGM (1,1). MFO-TFGM (1,1) performs higher forecasting accuracy.


2021 ◽  
Author(s):  
Irtaza Mohammad Syed

Harnessing green and renewable sources of energy is a future solution that addresses rising energy demands and growing environmental concerns. Among these, tapping wind energy using wind turbines appears to be one of the most promising solutions. A wind energy conversion system captures kinetic energy of wind and converts it into electrical energy. By nature, availability of wind energy is stochastic and intermittent. In contrast, electric power system expects a steady and planned supply of energy. This thesis addresses the gap in characteristics of wind energy supply and conventional electric energy demand. This thesis considers a doubly fed induction generator (DFIG) connected to a wind turbine to harness wind energy. The proposed topology connects a Supercapacitor through a buck-boost chopper to the DC link of rotor circuit. The Supercapacitor works to perform the job of a flywheel. The thesis proposes an appropriate control system that controls the output of the DFIG to constant value (Pref) eliminating short-term fluctuations. This control system works to control the buck-boost chopper and works as a inner control loop. Thereafter, this thesis proposes and optimization algorithm that considers short-term forecasted wind speeds (energy) for several minutes. It then optimizes to determine a minimum set of output values of the DFIG (Pref). It ensures that output of the DFIG has minimum changes thus minimizing intermittency in the DFIG output. This optimization algorithm forms the outer loop in the overall control strategy. The complete system is implemented in Matlab/Simulink and analysed in this thesis. The results demonstrate that the inner and outer control loops work to minimize output power oscillations and improve power quality.


2020 ◽  
Vol 61 (5) ◽  
pp. 118-124
Author(s):  
Thong Minh Le ◽  

Energy plays a very important role in the development of a country in many aspects of economic, social, environmental to security and defense. Correct forecasting of energy demand will make an important contribution to the implementation of energy, socio-economic and environmental policies and ensure the sustainable development of the country. Therefore, the selection of an appropriate energy forecasting model will play an important role in setting appropriate strategies and policies in the future. This article will synthesize energy forecasting models in the world, in-depth exploration of the POLES model and consider its applicability in energy forecasting in Vietnam.


2021 ◽  
Author(s):  
Irtaza Mohammad Syed

Harnessing green and renewable sources of energy is a future solution that addresses rising energy demands and growing environmental concerns. Among these, tapping wind energy using wind turbines appears to be one of the most promising solutions. A wind energy conversion system captures kinetic energy of wind and converts it into electrical energy. By nature, availability of wind energy is stochastic and intermittent. In contrast, electric power system expects a steady and planned supply of energy. This thesis addresses the gap in characteristics of wind energy supply and conventional electric energy demand. This thesis considers a doubly fed induction generator (DFIG) connected to a wind turbine to harness wind energy. The proposed topology connects a Supercapacitor through a buck-boost chopper to the DC link of rotor circuit. The Supercapacitor works to perform the job of a flywheel. The thesis proposes an appropriate control system that controls the output of the DFIG to constant value (Pref) eliminating short-term fluctuations. This control system works to control the buck-boost chopper and works as a inner control loop. Thereafter, this thesis proposes and optimization algorithm that considers short-term forecasted wind speeds (energy) for several minutes. It then optimizes to determine a minimum set of output values of the DFIG (Pref). It ensures that output of the DFIG has minimum changes thus minimizing intermittency in the DFIG output. This optimization algorithm forms the outer loop in the overall control strategy. The complete system is implemented in Matlab/Simulink and analysed in this thesis. The results demonstrate that the inner and outer control loops work to minimize output power oscillations and improve power quality.


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