A New Approach for Long-Term Stability Estimation Based on Voltage Profile Assessment for a Power Grid

Abstract

Load flow solutions refer to the steady-state stability of power systems and have a crucial role in the design and planning of slow-changing elements; e.g., in online tab changing actions, automatic generation control, over-excitation limiters and the power recovery characteristics of a load. Therefore, the purpose of this work was to show the connectivity between load flow analysis and long-term voltage stability using a generator model by introducing a novel voltage stability assessment based on the multi-machine dynamic model along with the load flow study for a power grid. The Euclidean distance (ED) was used to introduce a new voltage stability index based on the voltage phasor profile for real-time monitoring purposes. The effects of reactive power compensation, in addition to load-generation patterns and network topology changes in the system behavior, could be seen clearly on the voltage profiles of the buses. Thus, the increased values for the EDs of the buses’ voltage amplitudes—from 0 to around 1.5 (p.u.)—implied that the system was approaching the voltage collapse point, corresponding to the Jacobian matrix singularity of the load flow equation. Moreover, the weakest load bus with respect to any system change was also identified. Indeed, the criticality of any network interruption was in direct proportion to this voltage stability index. The proposed method was validated using the IEEE 118-bus test system.

Dynamic Reactive Power Allocation Method of Power Grid with High-Permeability PV Considering Transient Voltage Stability

“…The present study proposes a compensation sensitivity index (SI) that quantifies the relationship between the transient voltage stability index and the dynamic reactive power compensation amount, as depicted in Equation (22).…”

“…Ref. [22] proposed the voltage stability index, which is based on the Euclidean distance of the measured voltage vector curve, is to be utilized for the real-time monitoring of voltage. Ref.…”

“…To specifically assess the impact of installing dynamic reactive power compensation devices with identical capacity on TVDI s and TVPI s at different nodes, a 100 Mvar STATCOM is connected to each candidate node mentioned above. The sensitivity index (SI) for each node is then calculated using Equation (22). The calculation results are presented in Figure 9.…”

Multi-Indicator Fused Resilience Assessment of Power Grids Considering Wind-Photovoltaic Output Uncertainty during Typhoon Disasters

“…In the research of resilience assessment methods and indicators, some indicators describing the power grid usually include economic indicators [22], reliability indicators [23], and system stability indicators [24]. The typical performance transitions of a power grid facing disturbance events were often divided into the pre-disaster prevention stage, the mid-disaster resistance stage, and the post-disaster recovery stage [25,26].…”