Parametric Problems in Power System Analysis:Recent Applications of Polynomial Approximation Based on Galerkin Method

In power systems, there are many uncertainty factors such as power outputs of distributed generations and fluctuations of loads. It is very beneficial to power system analysis to acquire an explicit function describing the relationship between these factors(namely parameters) and power system states(or performances). This problem, termed as parametric problem(PP) in this paper, can be solved by Galerkin method,which is a powerful and mathematically rigorous method aiming to seek an accurate explicit approximate function by projection techniques. This paper provides a review of the applications of polynomial approximation based on Galerkin method in power system PPs as well as stochastic problems. First, the fundamentals of polynomial approximation and Galerkin method are introduced. Then, the process of solving three types of typical PPs by polynomial approximation based on Galerkin method is elaborated. Finally, some application examples as well as several potential applications of power system PPs solved by Galerkin method are presented, namely the probabilistic power flow, approximation of static voltage stability region boundary, and parametric time-domain dynamic simulation.

Framework for Artificial Intelligence Analysis in Large-scale Power Grids Based on Digital Simulation

The planning,design,operation,control and scientific research of power systems all require a variety of simulation analysis.Thus power grid simulation analysis is a fundamental supporting technology of large-scale power grids.In power grid simulation analysis,in addition to simulation calculations,there are many links for analysis and decision-making,relying on specialists.The introduction of advanced artificial intelligence technology provides a new method to improve the efficiency and accuracy of power grid simulation analysis.Nevertheless,the research of the related artificial intelligence technologies face a great deal of new challenges due to the complexity of the largescale power grid simulation data,including massive volumes,high dimensionality,strong coupling and complex correlations.Also a great deal of knowledge and experience need to be integrated in the process of analysis.In order to deal with these challenges,based on the existing works,this paper focuses on the core scientific problem of artificial intelligence analysis and decision making related to the massive simulation results of large-scale power grids,and proposes an artificial intelligence analysis method framework for large-scale power grids based on digital simulation,which includes the power grid simulation analysis knowledge model with application method,the power grid simulation knowledge mining method and the artificial intelligence models with transfer learning ability of diversified grids as well as analyzing and calculation adjusting for largescale power grid simulation results,etc.This work is expected to open up a new technical approach for large-scale power grid simulation analysis and provide strong technical support for the safe and stable operation of large-scale power grids.

A novel method to investigate voltage stability of IEEE-14 bus wind integrated system using PSAT

The maximum demand of power utilization is increasing exponentially from base load to peak load in day to day life.This power demand may be either industrial usage or household applications.To meet this high maximum power demand by the consumer,one of the options is the integration of renewable energy resources with conventional power generation methods.In the present scenario,wind energy system is one of the methods to generate power in connection with the conventional power systems.When the load on the conventional grid system increases,various bus voltages of the system tend to decrease,causing serious voltage drop or voltage instability within the system.In view of this,identification of weak buses within the system has become necessary.This paper presents the line indices method to identify these weak buses,so that some corrective action may be taken to compensate for this drop in voltage.An attempt has been made to compensate these drops in voltages by integration of renewable energy systems.The wind energy system at one of the bus in the test system is integrated and the performance of the system is verified by calculating the power flow(PF)using the power system analysis tool box(PSAT)and line indices of the integrated test system.The PF and load flow results are used to calculate line indices for the IEEE-14 bus test system which is simulated on PSAT.

New Algorithm for Fault Superimposed Quantities Based on Superimposed Network

A new algorithm for fault superimposed quantity(FSIQ)is presented and analyzed.The network equations are built up by combining fault superimposed networks(FSIN)with the boundary conditions of FSIQ at the fault point and are solved with the Newton iterative method.The algorithm has clear physical meaning and does not require an intermediate procedure to derive FSIQ.The algorithm is implemented by computer programming,and the results of calculations show that the algorithm is fast and accurate.The method can be used not only to calculate FSIQ in the complex power systems with simple or multiple faults,but also to analyze and evaluate the performance of the protective relays and automatic devices based on FSIQ.