Electric power systems will be operated in reliable and efficient situation considering
reactive power control and voltage stability management. Reactive power
margins are related to the voltage stability. The aspects are satisfied by designing
and operating of right voltages limits, maximizing utilization of transmission systems
and minimizing of reactive power flow. Therefore, controlling reactive power
and voltage is one of the major challenges of power system engineering.
Reactive power as the dissipated power is affected by capacitive and inductive
phenomena that they drop voltage and draw current in the form of heat or waste
energy. Reactive power is generated by the capacitors and generators, whereas it is
consumed by the inductors and is essential in the parallel connection circuits as
power factor controlling and power transmission lines.
Reactive power control and voltage stability aspects are effective in reliability of
electric power networks. Voltage instability commonly occurs as a result of reactive
power deficiency. The trends are to reduce reactive power and increase voltage
stability to improve efficiency and operation of power systems. There is a direct
relation between reactive power and voltage behavior which serves the voltage
collapse and rising effects in power systems.
Regulating the reactive power and voltage control should be done according to
flexible and fast controlled devices. Placement and adjustment of reactive power
play important roles in operation of reactive power compensation and voltage
control. Therefore, the operations of reactive power resources in the power systems
such as automatic transformer tap changer, synchronous condenser, capacitor
banks, capacitance of overhead lines and cables, static VAR compensators and
FACTS devices are very significant.
Reactive power control and voltage stability management are considered as
regional challenges to meet, which otherwise can cause the scale of blackouts
increase in the power systems. Theoretical and application issues in these areas help
us to identify problems related to reliability and stability of the power systems and
prevent the system degradation.