Online coherence identification using dynamic time warping for controlled islanding

Abstract

Controlled islanding is considered to be the last countermeasure to prevent system-wide blackouts in case of cascading failures. It splits the system into self-sustained islands to maintain transient stability at the expense of possible loss of load. Generator coherence identification is critical to controlled islanding scheme as it helps identify the optimal cutset to maintain system transient stability. This paper presents a novel approach for online generator coherency identification using phasor measurement unit (PMU) data and dynamic time warping (DTW). Results from the coherence identification are used to further cluster non-generator buses using spectral clustering with the objective of minimizing power flow disruption. The proposed approach is validated and compared to existing methods on the IEEE 39-bus system, through which its advantages are demonstrated.

A New Index based on Power Splitting Indices for Predicting Proper Time of Controlled Islanding

“…The matrix has interesting properties that can be extracted by applying a simple algebraic process. The diagonal elements of matrix KsGM represent the strength of coherency in each group while the off-diagonal elements show how strong is the coherency among different groups [17][18][19][20]. Moreover, the Laplacian matrix and its eigenvalues present valuable information about the power system.…”

A Robust Scheme for Coherency Detection in Power Systems

“…For ICI to be effective, correct, and adaptive, online identification of generators' coherency are essential. Moreover, the coherency between groups of generators can change over time, due to changing network topology and operating conditions, thus necessitating real-time coherency identification [4,5]. Online measurement-based coherency determination is made feasible due to the increasing deployment of phasor measurement units (PMU) in wide-area measurement systems (WAMS).…”

A novel measurement-based procedure for dynamic equivalents of electric power systems for stability studies using improved sine cosine algorithm

“…The only concern in measurement based approaches is their need for fast and accurate dynamic responses of the power system. Fortunately, current power systems are equipped with Wide Area Measurement System (WAMS) that utilize Phasor Measurement Units (PMUs) to collect data in real time, so with the aid of GPS and high-speed communication links, signals recorded by PMUs may be used to achieve online identification of dynamic equivalents [18,19].…”