NOVELTY - The apparatus comprises an inductor (120) comprising an inner face, an outer face, a first side, a second side and an annular core, coolant containment parts having an outer surface and an inner surface, a first tapered inductor mount, a tapered second inductor mount, first heat sink fins connected to the outer surface of the coolant containment parts, second heat sink fins connected to the inner surface of the coolant containment parts, a mounting system holding the inductor, a source holding coolant during use, and a heat exchanger for removing heat from the coolant.    USE - The apparatus is useful for cooling an inverter/converter system of an electrical system such as a backup power system including superconducting magnets, batteries, flywheels, digital virtual aerodynamics range (DVAR) technologies and renewable energy systems including solar cells, fuel cells, wind turbines, hydrogen converters and natural gas turbines.    ADVANTAGE - The apparatus is capable of efficiently and economically cooling the inverter/converter system thus enhancing performance, reliability and operating characteristics of the electrical system.    DETAILED DESCRIPTION - The apparatus comprises an inductor (120) comprising an inner face, an outer face, a first side, a second side and an annular core, coolant containment parts having an outer surface and an inner surface, a first tapered inductor mount, a tapered second inductor mount, first heat sink fins connected to the outer surface of the coolant containment parts, second heat sink fins connected to the inner surface of the coolant containment parts, a mounting system holding the inductor, a source holding coolant during use, a heat exchanger for removing heat from the coolant, and a return pipe connected to the heat exchanger. The coolant containment parts hold a non-conductive coolant within one-quarter inch of the inductor during use. The first inductor mount minimizes shaking of the inductor during use, and extends, from the inductor, beyond a plane formed by the first side of the inductor yielding room for the coolant during use. The second mount extends beyond a plane formed by the second side of the inductor yielding room for the coolant during use. The second inductor mount comprises a tapered outer surface contacting a rounded edge of the inner face of the inductor, and grooves, for flow of the coolant, on the tapered outer surface. The coolant comprises a halocarbon. The second heat sink fins directly contact the coolant during use. The mounting system prevents direct contact of the outer face of the inductor. The first side of the inductor and the second side of the inductor with the inner surface of the containment parts yield a gap for the coolant. The first and second tapered inductor mounts comprise holes for flow of the coolant, and contact a rounded edge of the inner surface of the inductor. The inductor exhibits: a permeability of less than 10 delta Gauss per delta Oersted at a load of 400 Oersteds; a linear inductance of -4400 B at 400 H to 4400 B at 400 H; linear flux density response to magnetizing forces over a range of -400 to 400 H; and a magnetic field of less than 5000 gauss at 200 Oersteds. The source delivers the coolant into the coolant containment parts. The return pipe returns the coolant to the source. An INDEPENDENT CLAIM is included for a method for controlling an operating temperature of an electrical system.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an electrical system.    Electromagnetic component (110)    Voltage or current source (114)    Switching system or element (116)    Inductor (120)    Capacitor. (122)