| 摘要 |
A single phase universal electric motor (100) of a portable electric tool, i.e. a motor having stator (2) and rotor windings (7) connected in series, the motor also including a motor control system (400) including: - a current measuring means (402) for directly or indirectly measuring the electric current in the rotor windings (7) providing a rotor current value/s, - an ambient temperature measuring/estimation means (404) for measuring or estimating the ambient air temperature providing an air temperature value/s, - a rotor temperature estimation means (406, 407, 408, 409, 410, 411) for estimating a rotor temperature at least based on the rotor current value/s and the air temperature value/s. |
