This document discusses static shunt compensation on transmission lines. Shunt compensation can increase steady-state transmittable power and control voltage profiles by using shunt reactors to minimize overvoltage under light loads and shunt capacitors to maintain voltage levels under heavy loads. Midpoint shunt compensation regulates voltage along line segments by exchanging only reactive power at the midpoint, significantly increasing transmittable power as the midpoint has the maximum voltage sag. End of line shunt compensation also provides voltage support to prevent instability.

1. STATIC SHUNT COMPENSATION
Presented by
T.S.L.V.Ayyarao
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2. OBJECTIVES OF SHUNT COMPENSATION
 Steady-state transmittable power can be increased.
 Voltage profile can be controlled.
 Shunt connected reactors (fixed or mechanically
switched) are applied to minimize line over voltage
under light load conditions.
 Shunt connected capacitors are applied to maintain
voltage levels under heavy load conditions.
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3. MIDPOINT REGULATION FOR LINE
SEGMENTATION
 Consider two bus transmission model with ideal var
compensator at the midpoint.
 The compensator divides line into 2 parts.
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4. MIDPOINT REGULATION FOR LINE
SEGMENTATION
 Midpoint var compensator exchange only reactive
power with the line.
 Real power is same at each terminal
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5. MIDPOINT REGULATION FOR LINE
SEGMENTATION
 The transmitted power is
 The relation between P, Q and angle
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6. MIDPOINT REGULATION FOR LINE
SEGMENTATION
 Midpoint shunt compensation significantly increase
the transmittable power.
 Mid point of the transmission line is the best
location for the compensator.
 Voltage sag is maximum at the mid point.
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7. END OF LINE VOLTAGE SUPPORT TO PREVENT
VOLTAGE INSTABILITY
 Consider a radial Transmission line
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8. END OF LINE VOLTAGE SUPPORT TO PREVENT
VOLTAGE INSTABILITY
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