Local identification of voltage instability from load tap changer response

A comprehensive assessment to propose an improved line stability index

“…According to the results of this analysis shown in Table 10, the outage of lines 16-19 and 01-02 results in the lowest loading margin, 89 and they are the most severe contingencies. In this regard, the outage of lines 01-02 and [16][17][18][19], which occur at t = 5 s and t = 25 s, respectively, will be simulated.…”

“…It should be noted that in deriving these indicators, active power ( P ) and reactive power ( Q ) are assumed to flow from the sending bus (SB) to the receiving bus (RB). Bus voltage stability indices: These indices are used to detect the distance between existing operating point and the maximum loading (ML) of load busses, which results in identification of weakest bus in the system. It is worth mentioning that the implementation of these indices is more complicated and they have more computational burden than line stability indices. Other indices: In addition to line and bus stability indices, there are some other methods like modal analysis, sensitivity analysis, artificial intelligence tools, on‐load tap‐changer (OLTC)–based methods, P‐Q and P‐V curve‐based methods, minimum singular value (MSV) of the power‐flow Jacobian, MSV of the reduced Jacobian, equivalent node voltage collapse index, and energy functions, which can be used to assess the stability of the whole power system. The main drawback of these indices is that they have high computational burden. Obviously, among above‐mentioned tools, the one that can provide more accurate assessment and has lower computational burden will be more effective for online applications.…”

“…It is worth mentioning that the implementation of these indices is more complicated and they have more computational burden than line stability indices. • Other indices: In addition to line and bus stability indices, there are some other methods like modal analysis, 11 sensitivity analysis, 12,13 artificial intelligence tools, 14,15 on-load tap-changer (OLTC)-based methods, [16][17][18] P-Q and P-V curve-based methods, 19 minimum singular value (MSV) of the power-flow Jacobian, 20 MSV of the reduced Jacobian, 21 equivalent node voltage collapse index, 22 and energy functions, 23 which can be used to assess the stability of the whole power system. The main drawback of these indices is that they have high computational burden.…”

Agent‐based identification and control of voltage emergency situations

“…It is assumed that the outage of a single element in the power system domain does not interfere with the ICT system and vice versa. The local identification of a voltage unstable situation is performed with a modified version of the eLIVES algorithm presented in [23]. The monitoring of the system response is activated in case of LTC tap adjustment.…”

“…In previous work, the authors have developed an agent-based solution for the prevention of voltage collapse by a coordinated activation of available countermeasures [21]. In parallel, in [22,23] the local identification of voltage emergency situations (LIVES) and extended-time LIVES (eLIVES) approaches have been presented for identifying voltage emergency situations solely based on local measurements gathered at load tap changer (LTC) controlled buses. The main contribution of this study is the extension of the aforementioned solutions by combining a robust algorithm for voltage stability assessment with a closed-loop logic for the execution of control actions in a MAS with a dedicated consideration of the inter-agent communication.…”