In motor manufacturing, copper alloys with high conductivity and high strength are widely used. The main copper parts are the stator, rotor and shaft head. In large motors, the windings need to be cooled by water or hydrogen, which is called dual water internal cooling or hydrogen cooling motors, which requires a large length of hollow wire.
Electric motors are a large consumer of electrical energy, accounting for about 60% of the total electrical energy supply. The cumulative electricity cost of a motor is very high. Generally, the cost of the motor is reached within 500 hours of initial operation, which is equivalent to 4 to 16 times the cost within a year, and can reach 200 times the cost during the entire working life. A small increase in motor efficiency can not only save energy, but also obtain significant economic benefits. The development and application of high-efficiency motors is currently a hot topic in the world. Because the energy consumption inside the motor mainly comes from the resistance loss of the winding; therefore, increasing the cross-section of the copper wire is a key measure for the development of high-efficiency motors. Compared with the first developed high-efficiency motors and traditional motors, the use of copper windings has increased by 25-100%. The U.S. Department of Energy is funding a development project to produce motor rotors using copper-cast technology.