This paper describes a new approach to online forecasting of power production from PV systems. The method is suited to online forecasting in many applications and in this paper it is used to predict hourly values of solar power for horizons of up to 36 h. The data used is 15-min observations of solar power from 21 PV systems located on rooftops in a small village in Denmark. The suggested method is a two-stage method where first a statistical normalization of the solar power is obtained using a clear sky model. The clear sky model is found using statistical smoothing techniques. Then forecasts of the normalized solar power are calculated using adaptive linear time series models. Both autoregressive (AR) and AR with exogenous input (ARX) models are evaluated, where the latter takes numerical weather predictions (NWPs) as input. The results indicate that for forecasts up to 2 h ahead the most important input is the available observations of solar power, while for longer horizons NWPs are the most important input. A root mean square error improvement of around 35% is achieved by the ARX model compared to a proposed reference model.

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Online Short-term Solar Power Forecasting

Particle Swarm Optimization (PSO) is a biologically inspired computational search and optimization method developed in 1995 by Eberhart and Kennedy based on the social behaviors of birds flocking or fish schooling. A number of basic variations have been developed due to improve speed of convergence and quality of solution found by the PSO. On the other hand, basic PSO is more appropriate to process static, simple optimization problem. Modification PSO is developed for solving the basic PSO problem. The observation and review 46 related studies in the period between 2002 and 2010 focusing on function of PSO, advantages and disadvantages of PSO, the basic variant of PSO, Modification of PSO and applications that have implemented using PSO. The application can show which one the modified or variant PSO that haven’t been made and which one the modified or variant PSO that will be developed.

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Particle Swarm Optimization: Technique, System and Challenges

https://vbn.aau.dk/ws/files/206009396/Correction.pdf

Practical operation strategies for pumped hydroelectric energy storage (PHES) utilising electricity price arbitrage

Phasor measurement units (PMUs) are rapidly being deployed in electric power networks across the globe. Wide-area measurement system (WAMS), which builds upon PMUs and fast communication links, is consequently emerging as an advanced monitoring and control infrastructure. Rapid adaptation of such devices and technologies has led the researchers to investigate multitude of challenges and pursue opportunities in synchrophasor measurement technology, PMU structural design, PMU placement, miscellaneous applications of PMU from local perspectives, and various WAMS functionalities from the system perspective. Relevant research articles appeared in the IEEE and IET publications from 1983 through 2014 are rigorously surveyed in this paper to represent a panorama of research progress lines. This bibliography will aid academic researchers and practicing engineers in adopting appropriate topics and will stimulate utilities toward development and implementation of software packages.

Synchrophasor Measurement Technology in Power Systems: Panorama and State-of-the-Art

Experimental validation of a real time energy management system for microgrids in islanded mode using a local day-ahead electricity market and MINLP

This paper presents novel corrective control actions to alleviate overloads in transmission lines by the Particle Swarm Optimization (PSO) method. Generator rescheduling and/or load shedding is performed locally, to restore the system from abnormal to normal operating state. The appropriate identification of generators and load buses to perform the corrective control action is an important task for the operators. Anew Direct Acyclic Graph (DAG) technique for selection of participating generators and buses with respect to a contingency is presented. The effectiveness of the proposed approach is demonstrated with the help of the IEEE 30 bus system. The result shows that the proposed approach is computationally fast, reliable and efficient, in restoring the system to normal state after a contingency with minimal control actions.

/pdf/a-corrective-strategy-to-alleviate-overloading-in-2rtogftiaf.pdf

A Corrective Strategy to Alleviate Overloading in Transmission Lines Based on Particle Swarm Optimization Method

This paper proposes an implementation procedure and performance testing of an algorithm comprise of Cumulative sum algorithm and power flow methods for fault detection in micro-grid systems. The Cumulative sum algorithm is found to be better than the traditional methods in the presence of noise, system frequency deviation, and other uncertainties for radial system. By monitoring the power Flows between buses along with cumulative sum algorithm, detection of faults in micro-grid system is carried out. The proposed digital Fault detection is implemented experimentally for performance testing on a test micro-grid system. Several transient disturbances viz. grid connection, single-phase to ground fault, 2 phase fault, 3 phase to ground faults, etc. occurring in different parts of the test micro-grid system are investigated experimentally.

An Efficient Fault Detection Algorithm for Micro-Grid

This paper presents the modeling and control of grid connected wind driven doubly fed induction generator (DFIG). Mathematical model of induction machine is developed in stator flux oriented dq frame which makes possible independent control of active and reactive powers. The power injected to the grid from the DFIG system is maintained constant irrespective of the wind speed with the help of active source in the DFIG system. A Battery Energy Storage System (BESS) is connected at the dc link to provide the active power support. Super synchronous and sub synchronous modes are simulated to verify the bidirectional power flow nature of back to back converter. The power fed from rotor side and stator side are analyzed during different modes of operation.

Transient modeling and control of DFIG for grid power leveling during variable wind speed

This paper investigates the impact on operating time delay and relay maloperation when 1,2 and 3 order analog antialiasing filters are used in numerical distance protection. RC filter with cut-off frequency 90 Hz is used. Simulations are carried out for different SIR (Source to line Impedance Ratio), load, fault type and fault conditions using SIMULINK, where the voltage and current signals are fed online to the developed numerical distance relay model. Matlab is used for plotting the impedance trajectory. Investigation results shows that, about 75 % of the simulated cases, numerical distance relay operating time is not increased even-though there is a time delay when higher order filters are used. Relay maloperation (selectivity) also reduces (increases) when higher order filters are used in numerical distance protection. Keywords—Antialiasing, capacitive voltage transformers, delay estimation, discrete Fourier transform (DFT), distance measurement, low-pass filters, source to line impedance ratio (SIR), protective relaying.

/pdf/investigating-performance-of-numerical-distance-relay-with-2qb21kryh6.pdf

Investigating Performance of Numerical Distance Relay with Higher Order Antialiasing Filter

The huge penetration of wind energy sources in the micro grid makes the grid operations more intrinsic. The intermittent nature of wind fluctuates the electrical power output of the wind generator. The battery storage mechanism are usually employed to mitigate these power fluctuations to an extend. This paper presents the modeling and control of grid connected wind driven Doubly Fed Induction Generator (DFIG) with Battery Energy Storage System (BESS) to mitigate the power fluctuations which arises due to the wind speed variations. Super capacitor is employed to improve the transient response and thus life of the battery. The battery State of Charge (SoC) is considered while charging and discharging of BESS. A 0.9 MW DFIG is simulated in PSCAD/EMTDC and verified the control schemes.

K. Shanti Swarup

Papers

A Corrective Strategy to Alleviate Overloading in Transmission Lines Based on Particle Swarm Optimization Method

An Efficient Fault Detection Algorithm for Micro-Grid

Transient modeling and control of DFIG for grid power leveling during variable wind speed

Investigating Performance of Numerical Distance Relay with Higher Order Antialiasing Filter

Modeling and control of DFIG with battery management system for grid power leveling