Hamidreza Zareipour

A review of wind power and wind speed forecasting methods with different time horizons

In recent years, environmental considerations have prompted the use of wind power as a renewable energy resource. However, the biggest challenge in integrating wind power into the electric grid is its intermittency. One approach to deal with wind intermittency is forecasting future values of wind power production. Thus, several wind power or wind speed forecasting methods have been reported in the literature over the past few years. This paper provides insight on the foremost forecasting techniques, associated with wind power and speed, based on numeric weather prediction (NWP), statistical approaches, artificial neural network (ANN) and hybrid techniques over different time-scales. An overview of comparative analysis of various available forecasting techniques is discussed as well. In addition, this paper further gives emphasis on the major challenges and problems associated with wind power prediction.

Short-Term Load Forecast of Microgrids by a New Bilevel Prediction Strategy

Microgrids are a rapidly growing sector of smart grids, which will be an essential component in the trend toward distributed electricity generation. In the operation of a microgrid, forecasting the short-term load is an important task. With a more accurate short-term loaf forecast (STLF), the microgrid can enhance the management of its renewable and conventional resources and improve the economics of energy trade with electricity markets. However, STLF for microgrids is a complex forecast process, mainly because of the highly nonsmooth and nonlinear behavior of the load time series. In this paper, characteristics of the load time series of a typical microgrid are discussed and the differences with the load time series of traditional power systems are described. In addition, a new bilevel prediction strategy is proposed for STLF of microgrids. The proposed strategy is composed of a feature selection technique and a forecast engine (including neural network and evolutionary algorithm) in the lower level as the forecaster and an enhanced differential evolution algorithm in the upper level for optimizing the performance of the forecaster. The effectiveness of the proposed prediction strategy is evaluated by the real-life data of a university campus in Canada.

Wind Power Prediction by a New Forecast Engine Composed of Modified Hybrid Neural Network and Enhanced Particle Swarm Optimization

Following the growing share of wind energy in electric power systems, several wind power forecasting techniques have been reported in the literature in recent years. In this paper, a wind power forecasting strategy composed of a feature selection component and a forecasting engine is proposed. The feature selection component applies an irrelevancy filter and a redundancy filter to the set of candidate inputs. The forecasting engine includes a new enhanced particle swarm optimization component and a hybrid neural network. The proposed wind power forecasting strategy is applied to real-life data from wind power producers in Alberta, Canada and Oklahoma, U.S. The presented numerical results demonstrate the efficiency of the proposed strategy, compared to some other existing wind power forecasting methods.

Application of information-gap decision theory to risk-constrained self-scheduling of GenCos

In a competitive electricity market, a generation company (GenCo) optimizes its operation schedules, referred to as self-scheduling, in order to maximize its profit. However, various sources of uncertainty, such as market price fluctuations or forced outage of generating units, may impact the GenCos profit. In this paper, a non-probabilistic information-gap model is proposed to model the uncertainties in short-term scheduling of a GenCo. The self-scheduling problem is formulated for risk-neutral, risk-averse, and risk-seeker GenCos. Robustness of the decisions against low market prices are evaluated using a robustness model. Furthermore, windfall higher profit due to unpredicted higher market prices is modeled using an opportunity function. The proposed models are applied to a 54-unit thermal GenCo.

Classification of Future Electricity Market Prices

Forecasting short-term electricity market prices has been the focus of several studies in recent years. Although various approaches have been examined, achieving sufficiently low forecasting errors has not been always possible. However, certain applications, such as demand-side management, do not require exact values for future prices but utilize specific price thresholds as the basis for making short-term scheduling decisions. In this paper, classification of future electricity market prices with respect to pre-specified price thresholds is introduced. Two alternative models based on support vector machines are proposed in a multi-class, multi-step-ahead price classification context. Numerical results are provided for classifying prices in Ontarios and Albertas markets.

Probabilistic Power Flow by Monte Carlo Simulation With Latin Supercube Sampling

In this paper, a Latin supercube sampling (LSS) combined with Monte Carlo simulation is presented to efficiently sample random variables in the probabilistic power flow (PPF) problem. The results of the LSS method are compared with other techniques, namely Latin hypercube sampling (LHS) and simple random sampling (SRS), using bin-by-bin histogram comparison. The simulation results are presented for the case of IEEE 118-bus test system.

Data centres in the ancillary services market

Ancillary services are the mechanisms power grids use to address short-term variability in supply and demand as well as the impact of power plant or transmission line failures. Organizations providing such services can earn revenue, or at least reduce their energy costs. This paper explores options for large data centres to reduce costs in this way. Simulation results are presented for a system that models the processing of a workload and the resulting energy use, focusing on the impact of providing specific types of ancillary services. Trace data recording the workload from three supercomputing facilities along with pricing information from a US-based electrical grid are used. Results presented show energy costs reduced by up to 12% with only a small impact on the quality of service provided to users of the data centre. Further reductions in energy costs are shown for data centres willing to cede more control over short-term energy consumption.

Economic Impact of Electricity Market Price Forecasting Errors: A Demand-Side Analysis

Several techniques have been proposed in the literature to forecast electricity market prices and improve forecast accuracy. However, no studies have been reported examining the economic impact of price forecast inaccuracies on forecast users. Therefore, in this paper, the application of electricity market price forecasts to short-term operation scheduling of two typical and inherently different industrial loads is examined and the associated economic impact is analyzed. Using electricity market price forecasts as the expected next-day electricity prices, optimal operating schedules and the associated costs are determined for each load. These costs are compared with those of a ¿perfect¿ price forecast scenario in which actual prices are used to determine the operating schedules. Numerical results and discussions are provided based on price forecasts with different error characteristics.

Wind power ramp events classification and forecasting: A data mining approach

Available wind power forecasting tools predict the future values of wind power production. System operators use those predictions to estimate the severity of wind power ramp up/down events, and determine the set of actions needed to manage those events. In this paper, a direct approach for predicting the severity of wind power ramp events is presented. Ramp events are categorized into ‘classes’, and available data are used to predict the class of future ramps. Support vector machines (SVM) are used as classifiers and an elaborate model for forming the set of inputs to the classifier is proposed. Numerical results based on the wind power data in Alberta, Canada, is presented.

Equilibria in an Oligopolistic Market With Wind Power Production

This paper proposes an approach for analyzing the impacts of large-scale wind power integration on electricity market equilibria. A pool-based oligopolistic electricity market is considered including a day-ahead market and a number of real-time markets. Wind power is considered within the generation portfolio of the strategic producers, and the uncertainty of wind power production is modeled through a set of plausible scenarios. The strategic behavior of each producer is modeled through a stochastic bilevel model. The resulting nonlinear equilibrium problem with equilibrium constraints (EPEC) is linearized and then solved. Numerical results for a test case with increasing levels of the wind power penetration is provided.