• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.62-68
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• 2015

Subsynchronous Resonance is a condition where the electrical power systems composed of generator and transmission line exchange energy with mechanical turbine-generator system at the frequency of the combined below the subsynchronous frequency. Therefore, the frequency of power systems should be associated with the subsynchronous resonance. This paper describes subsynchronous resonance by flexible frequency operation. It focuses on the characteristics and behavior of subsynchronous resonance. The subsynchronous resonance is being conducted by real-time digital simulator and the IEEE benchmark model for subsynchronous resonance have been utilized for the test systems.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.67-73
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• 1996

Subsynchronous resonance(SSR) causes a torsional shaft torque on the generator. Damages resulting from the uncontrolled SSR have resulted in the breakdown in the shaft and costs for replacement power. This paper is to determine the feasibility of controlling SSR by the fast modulation of series compensation capacitors. The presence of subsynchronous currents in the system was detected by a subsynchronous relay which was modeled by the transient analysis of control systems(TACS) in electromagnetic transients program (EMTP). The capacitor segments were switched by bi-directional thyristor switches. These were modeled into EMTP. The strategy to switch the capacitors were modeled as a closed loop system. The paper proves that effective control of SSR can be obtained only by the detuning of the system and the removal or blocking of subsynchronous energy from the system. (author). refs., figs., tabs.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.434-436
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• 1995

This paper was to determine the feasibility of controlling subsynchronous resonance(SSR) by the fast modulation of series compensation capacitors. The presence of subsynchronous currents in the system was detected by a subsynchronous relay which was modeled by the transient analysis of control systems (TACS) in the electromagnetic transients program (EMTP). The capacitor segments were switched by bi-directional thyristor swtiches. The paper proved that effective control of SSR can be obtained only by the detuning of the system and the removal or blocking of subsynchronous energy from the system.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.57-60
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• 1988

The investigation of subsynchronous resonance by utilities has resulted in proposed and applied method to mitigate or eliminate SSRdamage to turbine generators. Many papers presented various methods and devices that can be used as countermeasures for the SSR. This paper introduced the availability of Superconducting magnet energy storage as an countermeasure for the SSR in the capacitor compensated transmission line.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1017-1023
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• 2019

The increase of the alternate current frequency results in increased rotational speed of the electrical motors and connected pumps. The consequence for the reactor coolant pumps is increased flow in primary coolant system. Increase of the current frequency can be initiated by the subsynchronous resonance phenomenon (SSR). This paper analyses the implications of the SSR and consequential increase of the frequency on the nuclear power plant safety. The Simulink $MATLAB^{(R)}$ model of the steam turbine and governor system and RELAP5 computer code of the pressurized water reactor are used in the analysis. The SSR results in fast increase of reactor coolant pumps speed and flow in the primary coolant system. The turbine trip value is reached in short time following SSR. The increase of flow of reactor coolant pumps results in increase of heat removal from reactor core. This results in positive reactivity insertion with reactor power increase of 0.5% before reactor trip is initiated by the turbine trip. The main parameters of the plant did not exceed the values of reactor trip set points. The pressure drop over reactor core is small discarding the possibility of core barrel lift.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.3
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• pp.136-141
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• 2000

This paper presents the design of an H$\infty$ based robust Static Synchronous Compensator (STATCOM) supplementary controller to suppress the subsynchronous resonance (SSR) in the series-compensated system. The IEEE second benchmark, System-l model is employed for this study. In order to design the effective controller, the modal controllability and observability indices to the oscillation modes are considered. Comprehensive time domain simulations using a nonlinear system model that the proposed STATCOM supplementary controller can suppress the SSR efficiently in spite of the variations of power system operating conditions.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.143-145
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• 2001

In this paper, we present the modeling and resonance frequency of M/G set simulator, which is designed for SSR(Subsynchronous Resonance) phenomenon. Resonance frequency analysis is performed by modeling and simulation. This simulation is preparation for experiments. So, simulation scenario is constructed in basis of detail experiments and simulation is performed by Matlab.

• KIEE International Transactions on Power Engineering
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• v.3A no.3
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• pp.139-147
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• 2003

The paper presents a novel approach of constructing the state matrix of the multi-machine power system for SSR (subsynchronous resonance) analysis using the linearized equations of individual devices including electrical transmission network dynamics. The machine models in the local d-q reference frame are integrated with the network models in the common R-I reference frame by simply transforming their output equations into the R-I frame where the transformed output is used as the input to the network dynamics or vice versa. The salient feature of the formulation is that it allows for modular construction of various component models without rearranging the overall state space formulation. This universal SSR small signal stability program provides a flexible tool for systematic analyses of SSR small-signal stability impacts of both conventional devices such as generation systems and novel devices such as power electronic apparatus and their controllers. The paper also presents its application results to IEEE benchmark models.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.479-481
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• 1996

This paper describes a simulation model to analyze the dynamic performance of Unified Power Flow Controller which ran flexibly adjust the active and reactive power flow through the ac transmission line. An equivalent circuit to analyze the basic principle for the whole system operation was developed and a control system for the Unified Power Flow Controller was derived using vector control method. A computer simulation model with EMTP code was also conceived to evaluate the performance of the Unified power Flow Controller. The simulation results show that Unified Power flow Controller is very effective for controlling the power flow and damping the subsynchronous resonance in the power system.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.88-90
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• 2000

This paper presents a new method for representing complex power system phenomena using 3-D computer graphics animation. The proposed method was tested on both the generator dynamics phenomena and subsynchronous resonance phenomena. It is anticipated that the proposed method would be helpful for the operator training as well as power system education.