Showing papers by "Rajiv K. Varma published in 2006"
18 Jun 2006
TL;DR: In this paper, a static var compensator with a voltage controller has been employed at the induction generator terminal to damp the subsynchronous oscillations resulting from torsional interactions as well as induction generator self-excitation effects in such a wind energy conversion system (WECS).
Abstract: Subsynchronous resonance (SSR) is a potential problem in a series compensated power system. A wind farm employing self-excited induction generator (SEIG) connected to the grid through a series compensated transmission line may experience the same problem. This paper presents a study of subsynchronous oscillations resulting from torsional interactions as well as induction generator self-excitation effects in such a wind energy conversion system (WECS). It is shown that these two phenomena may cause system instability if proper preventive measures are not taken. A static var compensator (SVC) with a voltage controller has been employed at the induction generator terminal to damp the subsynchronous oscillations. It is also found that an auxiliary subsynchronous damping controller (SSDC) improves the damping of torsional oscillations. Extensive time domain simulations have been carried out using EMTDC/PSCAD to validate the performance of the SVC in preventing SSR.
46 citations
14 Mar 2006
TL;DR: The results of the commercial relay testing show the adverse effects of mid-point shunt-FACTS compensation of transmission line on both non-pilot and DCB distance protection schemes.
Abstract: This paper presents the performance of distance protection of transmission lines when compensated with shunt Flexible AC Transmission System (FACTS) Controllers/Devices. The performance of distance protection is evaluated for shunt-FACTS Controllers applied for mid-point voltage control. The impact of two types of shunt FACTS Controllers, Static Var Compensators (SVC) and Static Synchronous Compensators (STATCOM) on the transmission line distance protection are studied for different fault types, fault locations and system conditions. The dynamics of the shunt-FACTS Controllers with their associated control systems are considered and simulated using RSCAD/RTDS testing environment. The performance of both the basic/non-pilot distance scheme and a Directional Comparison Blocking (DCB) scheme are evaluated in this paper. The results of the commercial relay testing show the adverse effects of mid-point shunt-FACTS compensation of transmission line on both non-pilot and DCB distance protection schemes.
34 citations
TL;DR: In this article, the authors present a review of the important modeling techniques employed for developing FACTs controllers and examine the role of HVDC-Light transmission in exploiting the Off-shore wind energy resources.
Abstract: With more emphasis being laid on clean and renewable sources of energy, engineers look for the best possible ways to harness the wind energy to the maximum extent. FACTs controllers that were earlier being used at the transmission level find their use at generation level when it comes to extracting reliable and quality power from Wind Energy Conversion Systems (WECS). This article presents a review of the important modeling techniques employed for developing FACTs controllers and examines the role of HVDC-Light transmission in exploiting the Off-shore wind energy resources.
19 citations
05 Jun 2006
TL;DR: An auxiliary subsynchronous damping controller (SSDC) for a static VAr compensator (SVC) using the remote generator speed as the stabilizing signal has been designed in this paper.
Abstract: Subsynchronous resonance (SSR) is a potential problem in power systems having series compensated transmission lines. Flexible AC transmission systems (FACTS) controllers are widely applied to mitigate subsynchronous oscillations (SSO). With the advent of wide area measurement (WAM) technology, it is possible to measure the states of a large interconnected power system with synchronized phasor measurement units (PMU). In this paper the concept of using remote signals acquired through PMU has been proposed to damp SSR. An auxiliary subsynchronous damping controller (SSDC) for a static VAr compensator (SVC) using the remote generator speed as the stabilizing signal has been designed to damp subsynchronous oscillations. The IEEE first benchmark model is used to show the effectiveness of the controller. Extensive simulation results in EMTDC/PSCAD show that an SVC already installed in a transmission system with the primary objective of improving power transfer capability can also damp SSR with the auxiliary controller using remote generator speed. Finally, the effect of signal transmission delay is discussed.
17 citations
TL;DR: In this article, the rotor speed of a remotely located generator that significantly participates in the lightly or negatively damped electromechanical mode of oscillation is the most effective SVC control signal in damping electromagnetic oscillations in a power system.
Abstract: Rapid advances in Wide-Area Measurement (WAM) and communication technologies have made the use of remote system data/signals for effective control and operation of power systems possible. This paper presents a new concept of damping control of Static Var Compensator (SVC) based on rotor speeds of remotely located generators. The concept is demonstrated in three study systems: a single machine infinite bus system, a two-area four-machine 11-bus system, and the Western System Coordinating Council (WSCC) three-machine nine-bus meshed system. The performance of the proposed remote generator speed signal is compared with the traditionally utilised local signals for SVC damping control through nonlinear time domain simulations. It is shown that the rotor speed of the remotely located generator that significantly participates in the lightly or negatively damped electromechanical mode of oscillation is the most effective SVC control signal in damping electromechanical oscillations in a power system.
13 citations
16 Oct 2006
TL;DR: In this paper, a bibliography of HVDC transmission technology for the year 2004-2005 is presented, which provides a listing of various journal and conference papers in this area.
Abstract: This paper presents a bibliography of HVDC transmission technology for the year 2004-2005. It provides a listing of various journal and conference papers in this area.
13 citations
16 Oct 2006
TL;DR: In this paper, a bibliography of flexible AC transmission systems (FACTS) for the years 2004 and 2005 is presented, where the authors present a detailed discussion of the characteristics of each system.
Abstract: This paper presents a bibliography of flexible AC transmission systems (FACTS) for the years 2004 and 2005.
5 citations
16 Oct 2006
TL;DR: This paper presents a second continuation of Bibliography of FACTS for the years 2004 and 2005, and presents a new meta-analyses based on the data presented in this paper up to and including the second half of 2004.
Abstract: This paper presents a second continuation of Bibliography of FACTS for the years 2004 and 2005.
4 citations
TL;DR: The proposed agent-based software integration enables to "plug-and-play" new software applications developed by any vendor or developer with no or minimal changes in the existing software system at DCC, which permits the development of the distribution automation system in a phased manner by different vendors.
Abstract: This paper proposes an agent based integration strategy for software elements at the Distribution Control Centre (DCC). The proposed agent-based software integration enables to \"plug-and-play\" new software applications developed by any vendor or developer with no or minimal changes in the existing software system at DCC. Consequently, it permits the development of the distribution automation system in a phased manner by different vendors. The strategy has been successfully implemented and tested in an actual 10 MVA, 33 kV distribution system to validate its efficacy.