IEEE 1277-2020 pdf free.IEEE Standard General Requirements and Test Code for Dry-Type and Oil-Immersed Smoothing Reactors and for Dry-Type Converter Reactors for DC Power Transmission.
The temperature-rise limits of reactors should be adjusted if the cooling air ambient temperature exceeds the limits described in 5.1.2. If the cooling air ambient temperature at site exceeds either of the limits, then the specified temperature-rise limits for the reactor shall be reduced by the same amount as the excess. The adjusted temperature-rise limits shall be rounded to the nearest whole number of degrees Celsius.
Minimum ambient temperatures below 40°C should be specified as they may have an impact on the reactor.
If a particular current rating versus ambient temperature performance is required without additional loss of life, this shall be clearly defined in the specification.
For indoor reactors, the ambient temperature inside the reactor hall usually exceeds the limits described in 5.1 2 Higher ambient air temperature results in lower air density that contributes to reduce the dielectric withstand of air insulation. Thus, the specified dielectric withstand voltages shall be associated with the reactor hall ambient air conditions (e.g., maximum air temperature and associated minimum air humidity).
If dielectric tests are performed at usual laboratory ambient air conditions, correction flictors shall be applied to test voltages in order to take into account the most stringent ambient conditions prevailing in the reactor hail. Correction factors shall be calculated according to the methodology defined in IEEE Std 4TM,NOTE—Smoothing and converter reactors may be uniquely (custom) specified and designed for a specific location and set of operating conditions and, therefore, loading versus ambient temperature condition may be the norm, Establishing a current rating vcrsLls ambient temperature, etc., involves a number of considerations such as the thermal capability of the insulation system versus the winding operating temperature under rated conditions. This may be affected by a significant loss evaluation orother aspects of the specification. which reduces the temperature risc of the winding below the insulation system thermal capabilities.
For both oil-immersed and dry-type smoothing reactors, as wel las for dry-type converter reactors, the dielectric strength, which depends in whole or in part upon air for insulation, decreases as the altitude increases because of decreased air density. In the case of dry-type reactors, the encapsulated windings depend in part on air for dielectric strength. and the support insulators depend in total on air for dielectric strength. For oil-immersed smoothing reactors, the bushings depend in part on air for dielectric strength. If dielectric margins are adjusted in the specification to accommodate the operation of the smoothing reactor at a higher altitude, the dielectric test levels shall be as specified. Otherwise, for dry-type reactors specified for operation at altitudes between 1000 ni and 3000 m above sea level, but tested at normal altitude, the test voltages for external insulatioti (air insulation) shall be increased using the correction factors from Table I in IEEE Std C57.i2.00”-2015. For oil-immersed smoothing reactors, the bushings shall be tested at an appropriately increased test level, but the windings shall be tested at nominal value. In the case of dry-type reactors, both the insulators and windings shall be tested at the appropriate higher voltage. In any case, the purchaser’s specification shall state if the specified test levels have taken the higher operating altitude into account.IEEE 1277 pdf download.