Multi-layer spectral clustering approach to intentional islanding in bulk power systems

Abstract

Intentional controlled islanding (ICI) is a final resort for preventing a cascading failure and catastrophic power system blackouts. This paper proposes a controlled islanding algorithm that uses spectral clustering over multilayer graphs to find a suitable islanding solution. The multicriteria objective function used in this controlled islanding algorithm involves the correlation coefficients between bus frequency components and minimal active and reactive power flow disruption. Similar to the previous studies, the algorithm is applied in two stages. In the first stage, groups of coherent buses are identified with the help of modularity clustering using correlation coefficients between bus frequency components. In the second stage, the ICI solution with minimum active and reactive power flow disruption and satisfying bus coherency is determined by grouping all nodes using spectral clustering on the multi-layer graph. Simulation studies on the IEEE 39-bus test system demonstrate the effectiveness of the method in determining an islanding solution in real time while addressing the generator coherency problem.

An Effective Multi-Solution Approach for Power System Islanding

“…In this section, the performance of the proposed algorithm is compared with two state-of-the-art methods on the IEEE 39-bus model ( [17], [18]). The islanding methods in both papers are based on the spectral clustering approach (similar to the proposed method).…”

“…In [17], the main objectives are to minimize the active and reactive powers (P, Q) flow disruptions. In [18], correlation coefficients between bus frequency (f) components are also considered in the objective function beside active and reactive powers (P, Q).…”

“…The comparison analysis with [18] is also summarized in Table 4. As shown, the total power shortage is the same for both methods (199 MW).…”

“…Since the reactive power control is usually a local issue, complicating the algorithm in [17] does not result in significant improvement in the separation outcomes. This method is improved in [18] by adding the correction coefficients between bus frequency components in the algorithm.…”

“…• Proposing a straightforward islanding method that is easy to implement: In contrast to the state-of-the-art methods ( [17], [18]), which use active and reactive power and bus frequency, the proposed algorithm is based only on the active power flow in transmission lines and consequently, it is much simpler.…”