IEEE C57.135-2011 pdf free.IEEE Guide for the Application, Specification, and Testing of Phase-Shifting Transformers.
rated kVA of a phase-shifting transformer (PST): The apparent power at rated voltage for which the PST is designed.
rated phase angle or a phase-shilling transFormer (PST): The phase angle measured between the S and L terminals at maximum advance and/or retard tap position under no-load condition.
rated voltage of a phase-shifting transformer (PST): The phase-to-phase voltage to which operating and performance characteristics are referred. The voltage ratings are to be defined at no-load and based on turn ratios.
regulated circuit of a phase-shifting transformer (PST): The circuit on the output side of the PST in which it is desired to control the voltage, the phase relation, or both.
NOTE—In the regulated circuit the voltage may be held Constant, or may vary with or without relation to the phase angle depending on the type of PST.6
regulating bsinding: The winding of a single-core phase-shifting transformer (PST) or of the exciting unit of a two-core PST in which taps are changed to vary the phase angle.
retard phase angle: The phase angle expressed in degrees that results when the L terminal voltage lags the S terminal voltage.
series unit of a two-core phase-shifting transformer (PST): The core and coil unit that has one or more windings connected in series with the line circuit.
series inding(s) of a two-core phase-shifting transformer (PST): The winding(s) of the series unit that is(are) connected in series in the line circuit.
single-core design: A single-core phase-shifting transllwmer (PST) has all windings mounted on a single core.
S terminal: The S terminal is the terminal that is used as the fixed reference point when measuring the voltage phase angle of a phase-shifting transformer (PST).
6 Notes in text, tables, and figures of a standard are given tbr information only and do not contain ruircmcnts needed to implement this standard.
tis 0-core design: A two-core phase-shifting transformer(PST) consists of a series unit and a exciting unit. The series and the exciting unit can be either in one tank or in separate tanks.
4. ApplicatIon and theory of PSTs
4.1 Introduction
The development of large. high-voltage power grids has enabled power consumers to enjoy the benefits of more reliable and efficient service and has allowed generation sources to be. in sonic cases, located long distances from large load centers. Although large interconnected grids strengthen a power System’S reliability, complications can arise with the control of steady-state power flow along certain segments of the system. These complications can be attributed to several factors, including the impedance of parallel paths in the power grid, variation in power generation output, and variation in loads and load center phase angles.IEEE C57.135 pdf free download.