A novel real-time transient stability prediction method based on post-disturbance voltage trajectories

Abstract

With the wide application of phasor measurement units (PMU) and wide area measurement system (WAMS) in power system, the real time detection and emergency control of power system transient instability based on the wide-area measurements has brought wide attention. This paper presents a novel technique for predicting transient stability status of a power system following a large disturbance. The synchronously measured samples of the fundamental frequency voltage magnitudes are used to detect the stability. A stability criterion based on the volt-second integration of post-disturbance voltage trajectory is proposed for detecting the transient instability. The drop rate of voltage magnitude after clearing the fault is embedded into the proposed criterion since it indicates the severity of disturbance in some extent. There are two integration termination criteria for fast prediction. Compare with traditional transient stability prediction methods, in which the post-fault rotor angle and angular velocity samples are used to produce the instability criteria, the proposed method improves the reliability and rapidity of transient stability detection especially for the multiple swing instability cases. Studies with both IEEE 39 test system and China Sothern Power Grid indicates that the proposed method is effective. Keywords transient instability prediction, phasor measurement unit; post-fault voltage trajectory; volt-second integration criterion; voltage drop rate___________________________________ 978-1-4244-9621-1/11/$26.00 ©2011 IEEE

Development of a WAMS based test platform for power system real time transient stability detection and control

“…Based on the OMIB system, three indexes are calculated by Eqs. (17,18,19,20 and 21) including the convexity index in the phase of angle-angle acceleration (K 1 ), the convexity index in the phase of unbalanced powerangle (K 2 ) and the changing rate of the unbalanced electric power (K 3 ). When these three indexes are positive at the same time, the system is considered as transient instable.…”

“…6. Perturbed voltage trajectory integration criterion based detection module A technique for predicting transient stability based on perturbed voltage trajectories was presented in reference [18]. The main steps are explained as follows and the detailed algorithm flow chart is shown in Fig.…”

“…Various generator power angle prediction techniques [11][12][13][14] and different transient instability detection technologies [15][16][17][18] were proposed. Reference [15] proposed an emergency EEAC based transient instability detection technique by using the measured trajectory.…”

“…Reference [17] proposed a transient instability detection technology by means of the transient unbalance energy variation rate of the most seriously perturbed generator. Reference [18] proposed a transient instability detection criterion based on perturbed voltage trajectory. However, the response-based transient instability detection technologies have not been applied in actual power systems, lots of problems need to be solved such as the integrity of wide area measurement information, the tolerance of bad data, the influence of data transmission delay, the accuracy and rapidity of detection as well as the emergency control schemes.…”

On-line determination of transient stability status using multilayer perceptron neural network

“…Researchers have proposed a number of schemes for detecting transient instability [4][5][6][7][8][9][10][11][12][13][14]. These schemes have used power system input data such as rotor angle [4][5][6][7][8][9][10], bus voltage [10][11][12][13][14], mechanical input power [7,13], electromagnetic power [7,13], line current [11,14], generator frequency [10] and rotor speed [9]. Decision making tools such as artificial neural network [4], fuzzy logic [14], support vector machine [7,10] and decision trees [9,14] have also been employed.…”