The statistical tools of Complex Network Analysis are of useful to understand salient properties of complex systems, may these be natural or pertaining human engineered infrastructures. One of these that is receiving growing attention for its societal relevance is that of electricity distribution. In this paper, we present a survey of the most relevant scientific studies investigating the properties of different Power Grids infrastructures using Complex Network Analysis techniques and methodologies. We categorize and explore the most relevant literature works considering general topological properties, physical properties, and differences between the various graph-related indicators and reliability aspects. We also trace the evolution in such field of the approach of study during the years to see the improvement achieved in the analysis.

/pdf/the-power-grid-as-a-complex-network-a-survey-1ypu7fix7j.pdf

The Power Grid as a Complex Network: a Survey

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.

/pdf/online-short-term-solar-power-forecasting-1ljgpbshkb.pdf

Online Short-term Solar Power Forecasting

Advances and trends of energy storage technology in Microgrid

The statistical tools of Complex Network Analysis are of great use to understand salient properties of complex systems, may these be natural or pertaining human engineered infrastructures. One of these that is receiving growing attention for its societal relevance is that of electricity distribution. In this paper, we present a survey of the most important scientific studies investigating the properties of different Power Grids infrastructures using Complex Network Analysis techniques and methodologies. We categorize and explore the most relevant literature works considering general topological properties, differences between the various graph-related indicators and reliability aspects.

This paper provides a comprehensive survey on the state-of-the-art condition monitoring and fault diagnostic technologies for wind turbines. The Part II of this survey focuses on the signals and signal processing methods used for wind turbine condition monitoring and fault diagnosis.

/pdf/a-survey-on-wind-turbine-condition-monitoring-and-fault-3150r9pj27.pdf

A Survey on Wind Turbine Condition Monitoring and Fault Diagnosis—Part II: Signals and Signal Processing Methods

Large-scale blackouts have occurred frequently throughout the world. The blackouts that have occurred in recent years not only seriously affect the lives of local residents, but they also cause substantial economic losses. In particular, as modern society increasingly depends on electricity, power outages occurring at any time may result in devastating consequences. Accordingly, identifying the reasons for blackouts and implementing proper restoration measures are of particular importance. This paper analyses the sphere of influence, the scale of the effects, the restoration measures and the causes of previous worldwide blackouts. Based on the findings, suggestions for the development of China׳s power industry are then offered.

An analysis of previous blackouts in the world: Lessons for China׳s power industry

A microgrid can integrate distributed energy resources for satisfying load demand, moreover, solve reliability, safety and environment issues. Spinning reserves in microgrid such as battery, gas and diesel generator can provide support for more sustainable operation in distributed networks. Critical loads for microgrid are crucial for the system to support at any cost, whereas, a non-critical loads can be rescheduled based on the status of supply and demand mechanism. Microgrid is perfect for renewable energy integration, such as wind and solar, thus, it eliminates intermittency issues of these sources with proper operation and control strategy. In short, a proper secondary control is the key to achieve economic benefits from microgrid. Microgrid is also used to generate profit by sending excess power to the main grid via net metering approach and makes traditional consumer of power into producer at the same time. This study will provide insights into state-of-the-art energy management as well as generation/consumption prediction issues, practices and research status. This review study will embark the deep foundation to study the energy management or prediction related study for microgrids.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-gtd.2017.0354

Energy management system, generation and demand predictors: a review

Widespread application of distributed generation systems (DGS) will bring about new opportunities and challenges to power grid operation, control and electricity market The microgrid technology that integrates DGS, energy storage element and loads will be an effective approach to solve the interconnection of large-scale DGS with power grid In this paper the concept relevant to microgrid, present research situation and advancement of microgrid technology in other countries are presented in detail; the features and superiority of microgrid technology in operation, control, protection and economy are overall expounded Combining with the feasibility and economy of microgrid technology, the development prospect and research direction of microgrid technology are analyzed in depth, and it is pointed out that the microgrid can provide more reliable power supply for sensitive consumers under islanded operation

A Review on Microgrid Technology Containing Distributed Generation System

The vulnerability assessment algorithm of the bulk power grid based on complex network theory is proposed in this paper. The traditional research model of the power grid based on complex network theory is a graph with no direction and no weight at present. Because this model is far from the real power system, sometimes the wrong results may be gotten. In this paper, the models of components in the power grid are constructed detailedly, furthermore the weighted and directional graph is provided. First, the connecting formings among buses (instead in the traditional methods only substations are considered), lines, transformers and generators are simulated detailedly. Second, the power flow direction in the power grid is considered, and the components' tolerance to disturbances is also considered. Based on the proposed model, the power grid's tolerance to errors and attacks is analyzed. The key components and weak areas are indicated. At last, the robustness and fault dissemination mechanism of the power grid under cascading failures are analyzed based on the proposed method. The North China power grid is used as an example to validate the proposed method.

Vulnerability assessment of bulk power grid based on complex network theory

The interconnection of MW scale micro-turbine as a set of small, modular generation system at the LV distribution level have a significant impact on micro-grid performance. According to the dynamic characteristics of the Micro-turbine system, a complete mathematic model which considers the Micro-turbine and other electrical components as a whole is established in PACAD/EMTDC. The proposal model is built based on dynamics of each part and their interconnections. In addition, the double-SPWM control strategy of converter at power electronic interface is adopted as well. The simulation results show the model can maintain the output voltage and meet the power demand when the load changes, as well as mitigate the variation of DC voltage and value of DC side capacitor between rectifier and inverter to some extent, and thus greatly improve the capability of undertaking the influence of load variation. On the basis of the simulation results, the model is suitable for transient study and analysis in island mode of the microgrid as well as grid-connected operation.

Zhang Jianhua

Papers

An analysis of previous blackouts in the world: Lessons for China׳s power industry

Energy management system, generation and demand predictors: a review

A Review on Microgrid Technology Containing Distributed Generation System

Vulnerability assessment of bulk power grid based on complex network theory

Dynamic modelling and simulation of a Micro-turbine generation system in the microgrid