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Voltage Stability

The ability of a power system to maintain steady voltages close to nominal value.

Definition in an Article by a Task Force

Source: 1

Voltage stability refers to the ability of a power system to maintain steady voltages close to nominal value at all buses in the system after being subjected to a disturbance.

Short-term voltage stability involves dynamics of fast acting load components such as induction motors, electronically controlled loads, HVDC links and inverter-based generators. The study period of interest is in the order of several seconds, similar to rotor angle stability or converter-driven stability (slow interaction type). Accordingly, models with the same degree of detail as for the above stability classes must be used. In addition, for short-term voltage stability, the dynamic modeling of loads is essential, and short circuit faults near loads are the main concern.

Long-term voltage stability involves slower acting equipment such as tap-changing transformers, thermostatically controlled loads, and generator current limiters. It usually occurs in the form of a progressive reduction of voltages at some network buses. The maximum power transfer and voltage support are further limited when some of the generators hit their field and/or armature current time-overload capability limits. The study period of interest may extend to several minutes, and long-term simulations are required for analysis of system dynamic performance.

Definition in a European Union Regulation

Source: 2 (p6)

'voltage stability' means the ability of a transmission system to maintain acceptable voltages at all nodes in the transmission system in the N-situation and after being subjected to a disturbance;

Definition in China grid operation code

Source: 3 (p8)

电压稳定：电力系统受到扰动后，系统电压能够保持或恢复到允许的范围内，不发生电压崩溃的能力。

Translation:

Voltage Stability: The ability of a power system to maintain or restore system voltage within an allowable range after being subjected to a disturbance, without the occurrence of voltage collapse.

Last modified: 2026-01-18

Related: stability · frequency-stability · rotor-angle-stability · n-situation

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  1. N. Hatziargyriou and others (2021). Definition and Classification of Power System Stability - Revisited & Extended. https://doi.org/10.1109/TPWRS.2020.3041774 ↩

  2. (2017). Commission Regulation (EU) 2017/1485 of 2 August 2017 establishing a guideline on electricity transmission system operation. http://data.europa.eu/eli/reg/2017/1485/oj ↩

  3. SAMR and SAC (2022). GB/T 31464-2022: The Grid Operation Code. https://openstd.samr.gov.cn/bzgk/std/newGbInfo?hcno=2E138E6A6D540124290DBBA47FFA1E14 ↩