There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

On robust estimation of the location parameter

In the world, wind power is rapidly becoming a generation technology of significance. Unpredictability and variability of wind power generation is one of the fundamental difficulties faced by power system operators. Good forecasting tools are urgent needed under the relevant issues associated with the integration of wind energy into the power system. This paper gives a bibliographical survey on the general background of research and developments in the fields of wind speed and wind power forecasting. Based on the assessment of wind power forecasting models, further direction for additional research and application is proposed.

A review on the forecasting of wind speed and generated power

http://pierrepinson.com/31761/Literature/foley2012.pdf

Current methods and advances in forecasting of wind power generation

In this paper we present a new approach to detect, localize, and investigate the feasibility of classifying various types of power quality disturbances. The approach is based on wavelet transform analysis, particularly the dyadic-orthonormal wavelet transform. The key idea underlying the approach is to decompose a given disturbance signal into other signals which represent a smoothed version and a detailed version of the original signal. The decomposition is performed using multiresolution signal decomposition techniques. We demonstrate and test our proposed technique to detect and localize disturbances with actual power line disturbances. In order to enhance the detection outcomes, we utilize the squared wavelet transform coefficients of the analyzed power line signal. Based on the results of the detection and localization, we carry out an initial investigation of the ability to uniquely characterize various types of power quality disturbances. This investigation is based on characterizing the uniqueness of the squared wavelet transform coefficients for each power quality disturbance.

Power quality assessment via wavelet transform analysis

Data mining and analysis techniques in wind power system applications

Real-world power quality (PQ) events usually are infrequent and composing a dataset of significant size is a difficult task. Using simulators to generate data in wellcontrolled conditions is a very useful and popular option. This work presents a framework based on the ATP (Alternative Transient Program) simulator, which allows for evaluating data mining techniques applied to PQ events, such as fault classification using support vector machines (SVM) and neural networks.

A Framework for Evaluating Data Mining Techniques Applied to Power Quality

Event processing and analysis modules for evaluating the health conditions of transmission capacitor banks, their circuit switchers used to energize and de-energize them, and the power system condition following the energization for any evidence of significant increase in the harmonic distortion level or harmonic resonance are developed and implemented. Algorithms are based on those developed over a decade. The paper demonstrates the applications and efficacy of the modules using both simulated and actual capacitor switching event data.

Power quality event processing and analysis modules: Capacitors and their circuit switchers

The capability of routing power from one phase to another, interphase power flow (IPPF) control, has the potential to improve power systems efficiency, stability, and operation. To date, existing works on IPPF control focus on unbalanced compensation using three-phase devices. An IPPF model is proposed for capturing the general power flow caused by single-phase elements. The model reveals that the presence of a power quantity in line-to-line single-phase elements causes an IPPF of the opposite quantity; line-to-line reactive power consumption causes real power flow from leading to lagging phase while real power consumption causes reactive power flow from lagging to leading phase. Based on the model, the IPPF control is proposed for line-to-line single-phase power electronic interfaces and static var compensators (SVCs). In addition, the control is also applicable for the line-to-neutral single-phase elements connected at the wye side of delta-wye transformers. Two simulations on a multimicrogrid system and a utility feeder are provided for verification and demonstration. The application of IPPF control allows single-phase elements to route active power between phases, improving system operation and flexibility. A simple IPPF control for active power balancing at the feeder head shows reductions in both voltage unbalances and system losses.

Interphase Power Flow Control via Single-Phase Elements in Distribution Systems

This paper analyzes a blackstart operation of an unbalanced microgrid using a grid-forming inverter. The inverter sets the magnitude and frequency by generating its own frequency reference. It controls the positive- and negative-sequence voltages separately to mitigate voltage unbalance at its terminals. The current limiter of the inverter operates in the abc-frame to regulate the unbalanced current effectively. The performance of the grid-forming inverter is evaluated by blackstarting the islanded microgrid with a motor load. The inverter aims to achieve the following objectives during a blackstart process: 1) control the grid voltage at the rated value, 2) limit the inverter current during motor starting, and 3) maintain balanced voltage. The microgrid and grid-forming inverter are modeled and simulated in the PSCAD/EMTDC environment. The simulation results show that the grid-forming inverter is able to blackstart an islanded microgrid and maintain balanced voltage while supplying unbalanced loads. It is also shown that the inverter could start a motor while limiting the associated inrush current.

Surya Santoso

Papers

Data mining and analysis techniques in wind power system applications

A Framework for Evaluating Data Mining Techniques Applied to Power Quality

Power quality event processing and analysis modules: Capacitors and their circuit switchers

Interphase Power Flow Control via Single-Phase Elements in Distribution Systems

Blackstart of Unbalanced Microgrids Using Grid-Forming Inverter with Voltage Balancing Capability