直流电动机依靠直流电源运行,可分为永磁及励磁两大类。小功率直流电动机的磁场系统采用一块或多块永久磁铁构成,这种电机称为永磁直流电动机。而绝大多数直流电动机的主磁极都由直流电流来励磁。按励磁方式不同,又分为他励及自励两种类型:励磁电流由其他直流电源单独供给的为他励;励磁电流由电机自身供给的为自励。按励磁绕组联接方式的不同,自励型又分为并励、串励、复励三种。并励直流电动机的励磁绕组与电枢的两 DC motors rely on DC power supply can be divided into permanent magnet and excitation two categories. Low-power DC motor magnetic field system using one or more pieces of permanent magnets, this type of motor is called a permanent magnet DC motor. The vast majority of DC motor’s main pole by the DC current to excitation. Excitation by the different ways, is divided into two types of self-excitation and self-excitation: Excitation current from other DC power supply alone for his excitation; excitation current supplied by the motor itself is self-excitation. According to the different excitation winding connection, self-excitation type is divided into parallel excitation, string excitation, complex excitation three. Excitation DC motor excitation windings and armature of the two