Energooszczędność napędów o regulowanej prędkości obrotowej

Energy-saving electrical drive (Fig.1) is the type of drive working at its minimum required rotational speed (1). The algorithm of energy-saving drive operation can be applied to (Fig.2): - d.c. motor with electromagnetic excitation, - d.c. motor with permanent magnet excitation (Fig.4), - cage induction motor, - brushless motor with electronic commutator. The paper gives the comparison of these four motor types. The comparison criterion is the motor's volume, i.e. all the motors have identical outer dimensions as shown in Fig.3. If it is assumed that during steady-state operation the active power loss in all motors is kept constant deltaP-4900 W, then each motor's ratings (power and efficiency) are different (Table 1). The brushless motor is characterized by highest rated power (77 kW) and efficiency (94%). If rated power of brushless motor is decreased down to 53 kW, i.e. to the induction motor rated power value, then power loss in brushless motor drops down to 2300 W, and the efficiency rises to 95,8%.