Power transmission capability has traditionally been limited by either synchronous (or rotor angle) stability or by thermal loading capability of transmission line and equipment. Voltage stability is an important factor, which needs to be taken into consideration during the planning and operation of electrical power systems in order to avoid voltage collapse and subsequently partial or full system blackout. From the voltage stability analysis point of view, system operators need to know not only the severity of their system, but also the mechanisms that cause voltage instability. This paper presents study of different methods and techniques used to improve the voltage stability of electrical power systems. Conventional P-V curve and Q-V curve methods are taken as a basic analysis tool.

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Voltage Stability Voltage Collapse P-v Curve Q-v Curve