Cooling Solutions For High-capacity, Wide-range Voltage Regulators: The Importance Of Forced Oil Circulation

At capacity levels of wide range stabilizer for ac (typically ≥1MVA–5MVA), the internal heat generation of the equipment increases significantly. In oil-immersed structures, relying solely on natural convection cooling limits the heat exchange path and accelerates the oil temperature rise.

Therefore, when the nominal capacity of the voltage regulator reaches the 1MVA to 5MVA range, the system cooling scheme should incorporate oil pump circulation and a radiator in conjunction with a fan or water-cooling device to ensure continuous oil flow between the windings and the cooler.

In practical engineering, the design department will conduct thermal model analysis considering the voltage regulator's capacity, ambient temperature, radiator arrangement, and circulation pump parameters. If a large temperature difference is found between the top and bottom oil manifolds of the tank, or if the oil flow velocity is insufficient, it indicates that natural cooling is nearing its limit, and forced oil circulation becomes a reliable solution.