ASC — arc suppression coil (Petersen coil), up to 130/√3 kV, up to 1000 A

Description

Arc Suppression Coil (ASC) — an arc suppression coil for resonant neutral earthing of medium- and high-voltage networks. The reactor is connected to the neutral of a power or earthing transformer and, during a single-phase earth fault, compensates the network capacitive current, reducing the current at the fault point below the self-extinction threshold of the arc (about 35 A). As a result, most unstable faults on overhead lines clear themselves without tripping the feeder, which provides low fault rates in networks with Petersen coils, used in Scandinavia and other European countries for about eighty years. The ASC design is a modern reactor with a solid (no moving parts) core, one main and one auxiliary winding. A capacitor bank is connected to the auxiliary winding; the reactor is tuned to the network capacitance by switching various combinations of its elements. This solution provides a tuning range of 10–100 % with a resolution of less than 1 % and a retuning time from minimum to maximum position of less than 1 s — according to the manufacturer, the fastest coil on the market. The ASC can operate in parallel with reactors of any type, in particular using an existing reactor as the non-adjustable part. Two versions are produced: a sealed oil-immersed reactor (ONAN cooling, maintenance-free, no oil sampling) and an oil-free version for outdoor installation in a stainless steel enclosure, where the winding is made of MV cable and its screen serves as the auxiliary winding; the oil-free version needs no oil conservator and suits environmentally sensitive sites. Main parameters: voltage up to 130/√3 kV, current up to 1000 A, continuous or 2-hour operation, 50/60 Hz, auxiliary winding 690/345 V, temperature −40…+40 °C. Acceptance and type tests are performed per IEC 60076-1 and IEC 60076-6. The manufacturer has produced ASC since 1991 and has supplied more than 1000 reactors; together with an automatic tuning controller and a fault locator the reactor forms a complete compensation system, and with an added inverter compensator — a GFN system.

Technical specifications