Motor design rules (1)
1. The magnetic flux density of the motor core should not be too high or too low. When the core material, frequency and thickness of the silicon steel sheet are constant, the iron loss is determined by the magnetic flux density Ø, the magnetic flux density is too high, the iron loss is increased, and the motor efficiency is lowered. The iron core heat increases the temperature rise of the motor. Because the excitation power increases the motor power factor, the magnetic flux density of the core should not be too high. Try to avoid the supersaturation of the magnetization curve. If the magnetic density is too low, the motor material dosage will be used. Increase, the cost increases. The chip tooth is narrow, the magnetic density is high, that is, the slot entry line is large, that is, the core slot is larger.
2, motor slot full rate should not be too high or too low. Generally take 75 ~ 85% slot full rate low motor running wire loose in the slot. Easy to damage insulation. In addition, there are many gaps in the slot, due to poor air conduction, affecting the coil Heat dissipation increases the temperature rise of the motor.
3. The design of the motor slot shape should use the parallel tooth trapezoidal groove as much as possible and the grooved edge should not have sharp corners. Try to use the round bottom groove. Because the round groove is filled with aluminum, it is easy to mold and the stator chip is easy to insert.
4, the coil current density should not be too large or too small: the motor coil has a certain resistance. When the current passes through the coil, it will cause loss. The winding temperature rises, the motor design wants to reduce the resistance, to reduce the loss, improve the efficiency. Bold Wire diameter, reduce current density can reduce resistance, but the amount of coil material increases. Due to the increase of the groove area, the core magnetic density increases, which increases the excitation current and iron loss of the motor. Usually the induction motor j takes 3~7A/mm2 (The slot area is large, that is, the core slot is large when the chip is designed)
5. The width of the motor slot should not be too large. The slot is too large to make the air gap flux distribution uneven. The tooth harmonic increases and the additional loss increases, usually about 3.5mm. It is too small to enter the line.
6. The number of stator slots should not be too much or too small. The number of stator slots of the asynchronous motor is large, the magnetic potential, the potential waveform is good, the additional loss is small, and the motor efficiency is high. The number of slots also increases the contact area between the coil and the core, and the coil heats up well. Low temperature rise. Good performance but difficult production process. High cost
