The control of voltage and reactive power is a major
issue in power system operation, since the power system supplies power to a
vast number of loads and is feeding from many generating units, there is a
problem of maintaining voltages within required limits. As load varies, the
reactive power requirements of the transmission system vary. Since the reactive
power cannot be transferred or transported over long distances, voltage control
has to be effected by using special devices located through the system which
possess difficulties in keeping sufficient levels of voltage in the power
system network (Vournas, Sauer & Pai, 2006).
issue in power system operation, since the power system supplies power to a
vast number of loads and is feeding from many generating units, there is a
problem of maintaining voltages within required limits. As load varies, the
reactive power requirements of the transmission system vary. Since the reactive
power cannot be transferred or transported over long distances, voltage control
has to be effected by using special devices located through the system which
possess difficulties in keeping sufficient levels of voltage in the power
system network (Vournas, Sauer & Pai, 2006).
These difficulties have been occurring practically
since the first power systems started. Increasing requirements regarding both
the supply reliability and quality of supplied power force using more modern
(faster, more reliable, with a broader range of applications) devices. The
proper selection and coordination of equipment for controlling reactive power
and voltage stability are among the major challenges of power system
engineering (Devitt, 2011). These challenges gave birth to some selected
devices to control or compensate reactive power. In order to cover the
additional demand for reactive power and maintain the ability to control
voltage stability within the target range, various sources of reactive power, such
as SVC (Static Var Compensator) – static compensators of reactive power,
STATCOM – type systems (Static Compensator) static reactive power generators
and systems that combine both these solutions, which are referred to as SVC
based on STATCOM (Clair, 2013).
since the first power systems started. Increasing requirements regarding both
the supply reliability and quality of supplied power force using more modern
(faster, more reliable, with a broader range of applications) devices. The
proper selection and coordination of equipment for controlling reactive power
and voltage stability are among the major challenges of power system
engineering (Devitt, 2011). These challenges gave birth to some selected
devices to control or compensate reactive power. In order to cover the
additional demand for reactive power and maintain the ability to control
voltage stability within the target range, various sources of reactive power, such
as SVC (Static Var Compensator) – static compensators of reactive power,
STATCOM – type systems (Static Compensator) static reactive power generators
and systems that combine both these solutions, which are referred to as SVC
based on STATCOM (Clair, 2013).
In recent decades, there has been significant
progress in terms of equipment designed to improve the stability of voltage in
power systems. This is mainly due to the development of power supply systems in
the world, which requires seeking better ways of adjusting and controlling
power flows and voltage levels. Almost all power transported or consumed in
alternating current (AC) networks, supply or consume two of powers: real power
and reactive power. Real power accomplishes useful work while reactive power
supports the voltage that must be controlled for system reliability. Reactive
power is essential to move active power through the transmission and
distribution system to the customer (Larson, 2010).
progress in terms of equipment designed to improve the stability of voltage in
power systems. This is mainly due to the development of power supply systems in
the world, which requires seeking better ways of adjusting and controlling
power flows and voltage levels. Almost all power transported or consumed in
alternating current (AC) networks, supply or consume two of powers: real power
and reactive power. Real power accomplishes useful work while reactive power
supports the voltage that must be controlled for system reliability. Reactive
power is essential to move active power through the transmission and
distribution system to the customer (Larson, 2010).
For AC systems, voltage and current pulsate at the
system frequency. Although AC voltage and current pulsate at same frequency,
they peak at different time power is the algebraic product of voltage and
current. Real power is the average of power over cycle and measured by
volt-amperes or watt. The portion of power with zero average value called
reactive power measured in volt-amperes reactive or vars.
system frequency. Although AC voltage and current pulsate at same frequency,
they peak at different time power is the algebraic product of voltage and
current. Real power is the average of power over cycle and measured by
volt-amperes or watt. The portion of power with zero average value called
reactive power measured in volt-amperes reactive or vars.
