The problem of defining and classifying power system stability has been addressed by several previous CIGRE and IEEE Task Force reports. These earlier efforts, however, do not completely reflect current industry needs, experiences and understanding. In particular, the definitions are not precise and the classifications do not encompass all practical instability scenarios. This report developed by a Task Force, set up jointly by the CIGRE Study Committee 38 and the IEEE Power System Dynamic Performance Committee, addresses the issue of stability definition and classification in power systems from a fundamental viewpoint and closely examines the practical ramifications. The report aims to define power system stability more precisely, provide a systematic basis for its classification, and discuss linkages to related issues such as power system reliability and security.

Definition and classification of power system stability IEEE/CIGRE joint task force on stability terms and definitions

Characteristics of the UK wind resource: Long-term patterns and relationship to electricity demand

The demand of energy is increasing at an escalating pace and cannot be fulfilled entirely by conventional energy systems, due to their limited supplies. In addition to this they have a radical impact on the environment. In comparison to them hybrid energy systems are a suitable combination of renewable and non-renewable energy systems which keeps into account the advantages of both these systems, thus able to achieve reduction in cost of implementation and maintenance of the system, limited emission levels, improvement in reliability of the overall system etc. Designing of hybrid energy system for a locality and its implementation is an uphill task as the input parameters of the sources considered are randomly varying with time and are also independent of the load requirements. The paper encompasses review on various important sectors needed to be considered while designing and implementation of hybrid energy system; this includes configurations, criteria selection, sizing methodologies and control & energy management. This will help the designer to use suitable design constraints required while implementing hybrid energy system for grid connected or in off grid modes as per the requirement of the locality.

A review on configurations, control and sizing methodologies of hybrid energy systems

A review on sizing methodologies of photovoltaic array and storage battery in a standalone photovoltaic system

The paper describes and examines a technique which permits the power-flow problem in a power system to be analysed probabilistically instead of using normal deterministic methods. All the nodal loads and generation are defined as random variables and the power flow in each line is computed in terms of a probability density function. The expected values and standard deviation of each power flow are also calculated, and, in addition, the overall balance of power in the system is determined in terms of a density function. The purpose of this analysis is to account for the errors and statistical variations known to exist in the operation and planning of systems within one solution. This enables the power-flow problem to be treated objectively and allows quantitative assessment of reliability and security. The paper compares the results obtained probabilistically with those that would be obtained deterministically, and shows the much wider range of information gained in this type of analysis.

A. Bonaert

Papers

Power system reliability evaluation