Instantaneous Relaxation-Based Real-Time Transient Stability Simulation

Abstract

Real-time transient stability simulation is of paramount importance for system security assessment and to initiate preventive control actions before catastrophic events such as blackouts happen. Transient stability simulation of realistic power systems involves the solution of a large set of nonlinear differential-algebraic equations in the time-domain which requires significant computational resources. Exploitation of parallel processing techniques can provide an efficient and cost-effective solution to this problem. This paper proposes a fully parallel method known as instantaneous relaxation (IR) for real-time transient stability simulation. To validate the proposed method, two test systems have been implemented on an advanced PC-cluster-based real-time simulator. A comparison of the captured real-time results with those from the PSS/E software shows high accuracy.

Power System Dynamic Simulations Using a Parallel Two-Level Schur-Complement Decomposition

“…After each solution, waveforms are exchanged between neighboring sub-systems, and this process is repeated until global convergence. If the time interval of the WR is restricted to only one time step, then the Instantaneous Relaxation method [11] is formulated. These techniques provide significant acceleration, however, their convergence strongly depends on the partitioning and on the time window interval [12], [13].…”

“…Thus, at the k-th iteration, the systems (11)(12)(13)(14) are formulated. Equations (11) and (12) Equations (13) and (14) stem from the linearization of Eq.…”

“…First, the parallel update of the (11)(12)(13)(14) is shown in the upper shaded block. Next, the L + 1 sub-domain reduced systems are computed in parallel in the second shaded block, where each parallel task updates one of the systems (15)(16).…”

A new methodology for the purpose of real-time local control of transient stability

“…This stable equilibrium state (δ e , 0) is referred to as the instantaneous stable equilibrium state. Here, δ e is the instantaneous stable LPS angle that can be obtained from (5b) by setting its left side equal to zero and using (6a) and (9). However, if the values of E T and P T sustain, the instantaneous stable equilibrium becomes the stable equilibrium of the LPS.…”

“…Some new recent developments in transient stability assessment are reported in [7]- [8]. There are also research efforts in using parallel processing [9]- [10] to speed-up the time-domain simulations.…”