Desire Rasolomampionona

Power system stability enhancement using PSS and UPFC Lyapunov-based controllers: a comparative study

Recently it has been shown that it is possible to design a power system stabilizer (PSS) as well as an unified power flow controller (UPFC) controller using a non-linear multi-machine system model in conjunction with Lyapunovs direct method. In this paper the features of two controllers implementing the proposed control laws have been compared: the PSS constitutes a supplementary loop to the main automatic voltage regulator (AVR) and UPFC controller. Theoretical analysis is supported by the results of eigenvalues analysis and simulations tests, which highlighted the differences between the actions of compared controllers. The tests performed on a multi-machine system model have shown a good performance of both proposed controllers.

Problems Found During Testing Synchronous Digital Hierarchical Devices Used on Power Protection Systems

This paper examines testing methods and devices for sending data to line protection devices using the synchronous digital hierarchical (SDH) protocol. The paper has arisen as a result of cooperation between the Institute of Power Engineering and the Polish Power Electrical Utility Operator (PSE). The main objective of the tests was to investigate the possibilities of using already installed or new SDH telecommunication devices in power system protection systems. A range of protection functionality tests was considered along with SDH devices tests that focused on certain conditions and possible problems that may occur during normal operating conditions.

Damping of Power Swings Using a FACTS Device of the TCPS Type: Modelling and Laboratory Experiments

Considerations concerning the damping of power swings using a FACTS device like TCPS are presented in this paper. The case of a generator-infinite bus test system is taken into consideration. Phenomena have been analysed both by performing computer simulations of the mathematical model and experimental analysis in laboratory conditions. A short description is given of the laboratory set up equipped with a TCPS device used for the experimental analysis.

A modified power system model for AGC analysis

AUTOMATIC generation control (AGC) has been used for several years to meet the objective of maintaining the system frequency at nominal value and the net tie line power interchange from different areas at their scheduled values. One of the main components of AGC is Load frequency control (LFC), one of the major requirements in providing reliable and quality operation in multi-area power systems. In interconnected large power systems, variations in frequency can lead to serious large scale stability problems. A new model derived from [3] with substantial modifications is presented in this paper. One principal modification concerns the turbines and consists of the creation of aggregate turbine for each type of turbine, another important modification is the consideration of several types of turbines participating in the secondary control, and the final modification is the consideration of aggregate generation coefficient in forming the rotor angle input of the tie-line model.

Travelling wave fault location algorithm in HV lines — Simulation test results for arc and high impedance faults

This paper presents simulation test results of the travelling wave fault location algorithm used in high voltage (HV) lines. The algorithm based on a wavelet transform, is tested for different fault types, including high impedance faults (HIF) and arc faults. Automatic test procedure (with use of PSCAD/EMTDC, Matlab) enabled to perform vast number of simulations for each testing scheme. Simulation results from a PSCAD/EMTDC model are compared with EMTP-RV results in order to confirm the correctness of the testing scheme.

Evaluation of frequency deviations effects on performance of digital protection relays

Frequency deviations, which result from the changes in the dynamic balance between load and generation levels, are prime reasons of concern for power quality. The use of digital multifunction protective relays and their proper integration into power system is an important matter. However, the performance of digital relays depends on many factors and needs to be carefully evaluated. In this paper, the effects of frequency deviations on the operation and performance of multifunction digital distance relays are assessed and measured during laboratory tests in many conditions which show the weakness of relay with MHO settings to work properly during frequency deviation.

Testing methodology of modern digital power system protections

In the paper power system digital relay test types are presented. Different types of analysis to which relay communication systems should be submitted are described. Among them the following can be enumerated: communication control board, communication interface between the device and the local monitoring PC, communication monitoring systems between protective devices. Also a particular attention was paid to the description of tests which should be performed on network-based communication systems (i.e. protection devices using the UCA protocol) both on site and in laboratory conditions. Moreover test procedure of UCA-based devices and the laboratory bench destined for network-based device testing are described. Finally some test examples and their results are presented with the appropriate comments.

A simple real-time simulator for protection devices testing

The submitted paper presents the design of a simple real-time simulator devoted to protection devices tests, whose the operation principle is based on closed feedback loop. The device is the result of a series of scientific projects carried out at the the Protection and Control Laboratory of IEn-PW. The construction, the issues related to the operation principle along with some results of tests performed on the designed simulator are presented in the paper. The software part is based on MATLAB/Simulink package including libraries, while the hardware part consists of measurement cards installed in PC computers, a CMS156 amplifier and a dedicated matching circuit. The last section of the article contains a brief description of the expected possible improvements of the simulator in the future.

Next Generation of Power System Protection Automation – Virtual Power System Protections

This paper describes the concept and analysis of virtualization technology and possible virtualization scenarios, which can be used to create a new generation of intelligent electronic devices (IEDs). The overview of the concept was based on solutions used in conventional IT systems. A fully operational working lab environment, in which simulated IED models were implemented, has been successfully tested. Problems associated with environment launch are described. An analysis of the influence of virtual device time synchronization and resynchronization on their correct operations is performed. Time delays of communication when sending GOOSE messages between the IEDs using GOOSE packages are verified.

A modern laboratory test bench for power protection unit testing

In the submitted paper, a modern laboratory test bench for generating unit protections testing is described. Both physical construction and principle of operation are presented. The test bench is composed of: a laboratory stand with a functional front panel, one ABB REG 316*4 relay, one set of testing devices composed of Omicron™ CMC 156 testing unit and CMS 156 amplifier, one personal computer. Three configuration sets are used for the protection of generating units. Included is also the way how laboratory tests are conducted within the framework of student teaching process, using the above presented test bench. A few examples of tests results are presented in order to illustrate the operation of the laboratory stand.