Thermal-electromagnetic analysis of solid rotor induction machine

The increasing demand for high-speed direct-drive systems is driving a significant research effort on high-speed electrical machines. Thermal management becomes a significant aspect to deal with, as power loss per cooling surface area reduces as speed increases. Solid rotor induction machines are often considered at the high end of the speed spectrum as they offer a mechanically robust rotor structure. The current density distribution within their rotor structure typically results in high rotor losses and a significant portion of the total machine losses. In such machines, the current distribution in the rotor itself is highly dependent on the rotor resistance and hence on the rotor temperature distribution. This presentation details an effective model, coupling both the electromagnetic and thermal domains, to simulate the operation of solid rotor induction machines.