Study of Congestion Due To Contingency in 9-Bus Test System

Introduction. In recent years, numerous non-renewable and renewable energies are connected to the grid to meet the demand. Also, transient variation with loads poses the shortcomings for generating units, transmission and distribution networks. In this regard, the study on choice of suitable load modelling is essential to predict the system characteristics. The aspect of the research design is a ZIP load model, which, when combined with contingency criteria and constant-impedance, constant-current, and constant-power loads, produces realistic and long-term load representations. Purpose. The proposed technique, infers the single transmission line outage for obtaining the contingency ranking to ensure the system behavior. Methods. The proposed mathematical model with hybrid line stability ranking index has been used for observing the stability analysis with and without considering unified power flow controller. Results. The power system involves many unpredictable conditions or contingency conditions like single transmission line outage, double transmission line outage, generator outage and load variations. This paper mainly focuses on the single transmission line outage for obtaining the contingency ranking. Practical value. The recommended stability analysis has been very beneficial in establishing a secure transmission power system.

https://doi.org/10.20998/2074-272x.2023.1.10

Investigations on hybrid line stability ranking index with polynomial load modeling for power system security

With the recent blackouts in Texas, Manhattan, and NE US, the importance of analyzing outage is greater than ever. Contingency Analysis is helpful to increase the resiliency of power system by analyzing impact of different contingencies. The effect of single transmission line outage in a transmission network has been studied with IEEE 39 bus network. Each of the branches has been disconnected one at a time to find effect on generator constraints, voltage constraints of buses, transmission line loading and possibility of islanding. PSS®E Xplore 34 was used for the simulation. The results show that single transmission line outage may impact generator power factors, increase demand of reactive power from the generators, and overload other transmission lines. Transmission line outage may lead to several violations of system constraints leading to islanding. This study may help research on different impacts of single transmission line outage and improve power system resilience.

Single Line Outage Analysis on IEEE 39 Bus Network

AbstractThe contingency in power system occurs due to failure of any components such as transmission lines, generators, transformers, etc. Power system contingency ranking (PSCR) is an essential task of the power system engineers and planners to ensure the reliable and safe operation of the system. In this study, the PSCR is determined through two indices, i.e., voltage deviation index (VDI) and power deviation index (PDI). The VDI and PDI reflect the deviation of the voltage and line power, respectively, due to contingency. The PSCR is performed by calculating the overall index (OI) and the most vulnerable contingency is determined. Furthermore, the impact of the most vulnerable contingency is also analyzed in terms of voltage profile. The proposed PSCR method is applied on IEEE 14- and 30-bus systems. This presented study will be helpful for security analysis of the power system.KeywordsContingencyPower systemLoad flow 

Determination of Power System Contingency Ranking Using Novel Indices

The expansion of electric ships in the transportation sector, along with environmental advantages, has the potential to enhance the resilience and stability of coastline power grids during blackouts or emergencies through ship-to-grid technology. The power grids located in remote coastal and island communities often face high energy costs and are more vulnerable to blackouts due to their increased risk of natural disasters. Ship-to-grid technology offers an innovative localized solution that enables onshore utilities to avoid the need for installing excessive onland energy storage capacity to enhance stability and resiliency in the coastline power grid. Electric ships can provide a flexible source to restart power to critical facilities such as hospitals and communication networks. In this paper, a comprehensive scheme for integrating ships into the grid system is proposed, which involves a grid-forming control approach through a DClink connection. The approach employs a droop-based control strategy, current limiter control, and voltage source grid interface to regulate both voltage and frequency at various stages of the coastline power network restoration. The approach is verified using a 4-zone shipboard power system with grid-forming DClink connection, for black start of a modified IEEE 30-bus test system during a multi-step black start and re-energization process.

Black Start of Coastline Power Networks From Grid-forming Ship-to-Grid Services

Contingency analysis is significant for power system protection. It is the analysis of a power system during non-functionality of equipment(s) or device(s). Contingencies in a power system can occur due to internal component failures or due to external factors like lightning and overloading of equipment. In this paper, contingency analysis has been done for an IEEE 30 bus system. Outage of generators, transmission lines and transformers have been carried out and the results are analysed. Under transmission line contingency, single line outage, double line outage and single circuit line with a compensator outage has been performed. Load flow before and after the contingency have been analysed using PSAT software. Performance indices have been used to rank the severity of each component's contingency. Performance index is given by the sum of active power performance index and voltage performance index. Similarly, a parameter known as Severity index is used to evaluate the effect on all transmissions lines in the power system due to outage of each component.

Pragathi Manohar

Papers

Contingency analysis of an IEEE 30 bus system