DOKa / DOKRa — oil-immersed shunt (compensation) reactors, 50–11,200 kVAr, 0.4–115 kV

Description

Oil-immersed compensation (shunt) reactors DOKa are designed to compensate the capacitive reactive power arising from the operation of synchronous machines and in long low- and medium-voltage cable networks when they are lightly loaded. The reactors protect the network from periodic excess of capacitive reactive power, limit voltage rise under light-load conditions, and help meet the system operator's requirements for reactive power exchange. The range covers powers of 50–11,200 kVAr at network voltages of 0.4–115 kV. Standard DOKa types for 6.3 kV, 15.75 kV and 21 kV are rated 75, 250, 400, 630, 800, 1000, 1600 and 2000 kVAr, and at 21 kV also 3400, 4000 and 5000 kVAr. For high-voltage networks, the DOKa 8000/115 (8000 kVAr, 115 kV) and the DOKRa 11200/110 (11,200 kVAr, 110 kV) are produced. The parameters and equipment of each reactor are agreed with the customer. Design: three-limb core of cold-rolled electrical steel with inorganic insulation; clamping studs in the middle part of the yoke ensure uniform compression of the limbs. Windings of electrolytic copper: round enamelled or shaped conductor in paper insulation; oil channels between the windings provide circulation and cooling. Screw compression of the windings excludes their vibration in operation; the fixing and design provide high dielectric strength, lightning withstand and short-circuit withstand. An earthing scheme for all structural elements is developed for overvoltage protection. The tank is a welded steel tank with stiffening ribs; heat is dissipated by sheet radiators or corrugated walls; a trolley with rollers repositionable for longitudinal and transverse movement. Operating conditions: temperate climate, outdoor installation or a ventilated room free of dust and aggressive gases, temperature −25…+40 °C (annual average up to +20 °C), altitude up to 1000 m, frequency 50 Hz; special versions are possible. Applications: distribution network substations with a large share of cable lines, renewable energy sites and industrial networks. Conformity with PN-EN 60076-6 is confirmed by certificates.

Technical specifications