Coordinated Control of SVS and CSC for Damping Power System Oscillations
30 Jun 2010-International Journal on Electrical Engineering and Informatics-Vol. 2, Iss: 2, pp 84-101
TL;DR: In this article, a new SVS auxiliary controller, known as the combined derivative of reactive power and derivative of computed internal voltage (CDRPDCIV) auxiliary controller was developed and incorporated in the SVS control system located at the middle of a series compensated long transmission line to get most effective damping effect.
Abstract: In this paper the effectiveness of Static Var System (SVS) auxiliary controller in coordination with controlled series compensation has been demonstrated for damping power oscillations for wide range of operating conditions. A new SVS auxiliary controller, known as the combined derivative of reactive power and derivative of computed internal voltage (CDRPDCIV) auxiliary controller has been developed and incorporated in the SVS control system located at the middle of a series compensated long transmission line to get most effective damping effect. The first IEEE benchmark model for analysis of torsional modes has been adopted. Eigen value analysis study is conducted for various levels of power transfer and series compensation. The results of eigen value analysis are validated by carrying out time domain analysis study based on non linear model. The proposed SVS auxiliary controller in coordination with CSC with its bang - bang form of control is very effective in damping power system oscillations over a wide operating range under large disturbance conditions thus enhancing the Transient performance of the power system.
Citations
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01 Nov 2014
TL;DR: In this paper, a method is proposed to select supplementary signals for a static var compensator in IEEE first benchmark model, where different input output controllability analyses are used to assess the most appropriate supplementary signals to achieve effective damping of torsional oscillations.
Abstract: A method is proposed in this paper to select supplementary signals for a static var compensator in IEEE first benchmark model. Different input output controllability analyses are used to assess the most appropriate supplementary signals for the static var compensator (SVC) for achieving effective damping of torsional oscillations. After placing the SVCs based on their primary functions, the most appropriate input signal for supplementary controller is also selected. The eigenvalues and hankel singular values of the system are computed incorporating various supplementary signals in the SVC for selecting the best supplementary signal.
1 citations
Cites background from "Coordinated Control of SVS and CSC ..."
...Also, there are two possible ways to check the observability of the above system (17): • (A,C) is observable if and only if matrix Ψ,defined as Ψ= has full rank n. • (A,C) is observable if and only if the observability Gramian matrix defined as has full rank n and, thus, is positive definite....
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References
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TL;DR: Concepts are described which provide design engineers with the insight to control performance and the understanding needed to ensure the secure operation of the bulk transmission system.
Abstract: The design of controllers sited in the transmission network for damping interarea power oscillations requires several types of analytical tools and field verification methods. Probably the most important aspect of such control design is the selection of proper feedback measurements from the network. This paper describes concepts which provide design engineers with the insight to control performance and the understanding needed to ensure the secure operation of the bulk transmission system. Specific attention is directed to procedures for selecting feedback signals. >
385 citations
TL;DR: In this paper, a static var compensator (SVC) with a simple voltage regulator is employed at the induction-generator (IG) terminal in addition to the fixed shunt capacitor for dynamic reactive power support.
Abstract: The rapid growth of wind power systems worldwide will likely see the integration of large wind farms with electrical networks that are series compensated for ensuring stable transmission of bulk power. This may potentially lead to subsynchronous-resonance (SSR) issues. Although SSR is a well-understood phenomenon that can be mitigated with flexible ac transmission system (FACTS) devices, scant information is available on the SSR problem in a series-compensated wind farm. This paper reports the potential occurrence and mitigation of SSR caused by an induction-generator (IG) effect as well as torsional interactions, in a series-compensated wind farm. SSR suppression is achieved as an additional advantage of FACTS controllers which may already be installed in the power system for achieving other objectives. In this study, a wind farm employing a self-excited induction generator is connected to the grid through a series-compensated line. A static var compensator (SVC) with a simple voltage regulator is first employed at the IG terminal in addition to the fixed shunt capacitor for dynamic reactive power support. The same SVC is shown to effectively damp SSR when equipped with an SSR damping controller. Also, a thyristor-controlled series capacitor (TCSC) that is actually installed to increase the power transfer capability of the transmission line is also shown to damp subsynchronous oscillations when provided with closed-loop current control. While both FACTS controllers-the SVC and TCSC-can effectively mitigate SSR, the performance of TCSC is shown to be superior. Extensive simulations have been carried out using EMTDC/PSCAD to validate the performance of SVC and TCSC in damping SSR.
296 citations
TL;DR: In this paper, a robust damping control design for multiple swing mode damping in a typical power system model using global stabilizing signals is presented, based on the mixed-sensitivity formulation in a linear matrix inequality (LMI) framework.
Abstract: This paper demonstrates a robust damping control design for multiple swing mode damping in a typical power system model using global stabilizing signals. A multiple-input, single-output (MISO) controller is designed for a thyristor-controlled series capacitor (TCSC) to improve the damping of the critical interarea modes. The stabilizing signals are obtained from remote locations based on observability of the critical modes. A H/sub /spl infin// damping control design based on the mixed-sensitivity formulation in a linear matrix inequality (LMI) framework is carried out. It is shown that, with local signal, supplementary damping control through three flexible AC transmission systems (FACTS) devices is necessary to provide damping to the three dominant interarea modes. On the other hand, the use of global signals has been shown to improve the damping of all the critical interarea modes with a single controller for the TCSC only. The damping performance of the centralized controller was examined in the frequency and the time domain for various operating scenarios. The controller was found to be robust against varying power-flow patterns, load characteristics, tie-line strengths, and system nonlinearities, including saturation.
257 citations
TL;DR: In this paper, the residue method was applied to linearized power system equations and obtained a generalized form which is suitable for different controller input/output channels and therefore suitable for control devices.
Abstract: The thyristor controlled series compensator (TCSC), a prominent FACTS device, can rapidly modulate the impedance of a transmission line, resulting in improvement of power system performance. The purpose of the work reported in this paper is to design a controller to damp interarea oscillations. The authors have applied the residue method to linearized power system equations and obtained a generalized form which is suitable for different controller input/output channels and therefore suitable for different control devices. This method, together with modal sensitivities, is applied to TCSCs to determine the location, feedback signal and controller design. The damping result is illustrated by comparing changes in damping ratio and identifying the increase of transfer capacity.
210 citations
TL;DR: In this paper, the use of damping torque technique to examine the efficacy of various control signals for reactive power modulation of a midpoint-located static VAr system (SVS) in enhancing the power transfer capability of long transmission lines is considered.
Abstract: The use of a damping torque technique to examine the efficacy of various control signals, for reactive power modulation of a midpoint-located static VAr system (SVS) in enhancing the power transfer capability of long transmission lines is considered. A new auxiliary signal, the computed internal frequency (CIF), is proposed which synthesizes the internal voltage frequency of the remote generator from electrical measurements at the SVS bus. It is demonstrated that this signal is far superior to other conventional auxiliary control signals in that it allows full utilization of the network transmission capacity. The damping torque results are correlated with those obtained from eigenvalue analysis. >
186 citations
"Coordinated Control of SVS and CSC ..." refers background in this paper
...Besides, voltage control and improvement of transmission capability SVS in coordination with auxiliary controllers [3, 4, 6, 10] can be used for damping of power system oscillations....
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...In recent years SVS has been employed to an increasing extent in modern power systems [1, 4, 10] due to its capability to work as Var generation and absorption systems....
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...Constants a1 to a8 and b1to b6 are defined in [10]....
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