300 questions about electric bicycle electrical knowledge-motor knowledge

Section 1 Motor 1. What is a motor? Answer: A motor is a component that converts battery electrical energy into mechanical energy and drives the wheels of an electric vehicle to rotate. 2. What is a stator? Answer: The part that does not rotate when the brush or brushless motor is working.Wheel hubThe motor shaft of a brushless or brushless toothless motor is called a stator, and this type of motor can be called an inner stator motor. 3. What is a rotor? Answer: The part that rotates when a brush or brushless motor is working. The shell of the hub-type brushed or brushless gearless motor is called the rotor, and this type of motor can be called an external rotor motor. 4. What is carbon brush? Answer: The inside of the brushed motor rests on the surface of the inverter. When the motor rotates, the electric energy is sent to the coil through the inverter. Because its main component is carbon, it is called carbon brush, which is easy to wear. It should be regularly maintained and replaced, and carbon deposits should be cleaned up. 5. What is a brush grip? Answer: The mechanical guide groove that holds and maintains the position of the carbon brush in the brushed motor. 6. What is a phase inverter? Answer: Inside the brush motor, there are mutually insulated strip metal surfaces. When the motor rotor rotates, the strip metal alternately touches the positive and negative poles of the brush to achieve alternating positive and negative changes in the current direction of the motor coil to complete the brush motor coil. Commutation. 7. What is the phase sequence? Answer: The arrangement order of the brushless motor coils. 8. What is magnetic steel? Answer: Generally used to refer to magnetic materials with high magnetic field strength. Electric vehicle motors use neodymium iron boron rare earth magnets. 9. What is a brushed motor? Answer: When the motor is working, the coil and commutator rotate, but the magnetic steel and carbon brush do not rotate. The alternating current direction of the coil is changed by the inverter and the brush that rotate with the motor. In the electric vehicle industry, brush motors are divided into high-speed (High Speed) brush motors and low-speed brush motors. There are many differences between a brushed motor and a brushless motor. From the name, you can see that the brushed motor has carbon brushes, and the brushless motor does not have carbon brushes. 10. What is a brushless motor? Answer: The controller provides direct current with different current directions to achieve the alternating current direction of the coil in the motor. There are no brushes and inverters between the rotor and the stator of the brushless motor. 11. How does the motor realize commutation? Answer: When the brushless or brushed motor is rotating, the energization direction of the coil in the motor needs to be alternately changed, so that the motor can rotate continuously. The commutation of the brush motor is completed by the commutator and the brush, and the brushless motor is completed by the controller. 12. What is lack of phase? Answer: In the three-phase circuit of the brushless motor or the brushless controller, one phase cannot work. The lack of phase is divided into the main phase lack of phase and Hall lack of phase. The performance is that the motor is shaking and can not work, or the rotation is weak and the noise is loud. The controller is easy to burn out when working in the state of lack of phase. 13. What are the common types of motors? Answer: Common motors include: brushed hub motor, brushless geared hub motor, brushless gearless hub motor, brushless geared hub motor, side mounted motor, etc. 14. How to distinguish high and low speed motors from the types of motors? Answer: A brushed geared hub motor and brushless geared hub motor are high speed motors; B brushed gearless hub motor and brushless geared hub motor are low speed motors. 15. How is the efficiency of the motor defined? Answer: The efficiency of a motor refers to the ratio of the mechanical energy output by the motor to the electrical energy provided by the power supply. It is represented by the letter "り". 16. How are brushless motors classified?Answer: From the phase angle, it can be divided into two categories, namely, the brushless motors with 60° and 120° phase angles; according to the speed (Tempo), it can be divided into high speed (High Speed) brushless motors and low speed brushless motors. Brush motor; according to whether the motor has a positionsensorCome to divide, and divide into have positionsensorBrushless motors and brushless motors without position sensors. 17. What is a sensorless brushless motor?Answer: For a position sensorless brushless motor, you must first pedal up the vehicle to make the motor have a certain degree of rotation.Rotating speedAfter the temperature (Tempo), the controller can recognize the phase of the brushless motor, and then the controller can supply power to the motor. Because it cannot achieve zero-speed start, it is rarely used. But because there is no sensor, one point of failure is missing, and its cost is lower. 18. What is the approximate range of power consumption of the brushless motor Hall? Answer: The power consumption of the brushless motor Hall is roughly in the range of 6mA-20mA. 19. What is the voltage range of the brushless motor Hall? Answer: The voltage range of the brushless motor Hall is generally 3-24V. 20. At what temperature can a general motor work normally? What temperature can the motor withstand at most? Answer: If the temperature of the measured motor cover (Guy) exceeds the ambient temperature by more than 25 degrees, it indicates that the temperature rise of the motor has exceeded the normal range. Generally, the temperature rise of the motor should be below 20 degrees. Generally, the motor coil is wound by enameled wire, and when the temperature of the enameled wire is higher than about 150 degrees, the paint film will fall off due to the high temperature, causing the coil to short circuit. When the coil temperature is above 150 degrees, the temperature of the motor housing is about 100 degrees, so if the temperature of the housing is used as the basis, the maximum temperature the motor can withstand is about 100 degrees. 21. The temperature rise of the motor should be below 20°C, that is, the temperature of the motor end cover (Guy) exceeding the ambient temperature should be less than 20°C, but what is the reason for the motor heating over 20°C? Answer: The direct cause of the motor heating is due to the large current. Generally, it may be caused by short circuit or open circuit of the coil, low efficiency of the motor in the demagnetization of the magnet, etc. The normal situation is that the motor runs for a long time with high current. 22. How to measure the phase angle of a brushless motor? Answer: Turn on the power of the controller, and the controller will supply power to the Hall element, and the phase angle of the brushless motor can be detected. The method is as follows: use the +20V DC voltage range of the multimeter, connect the red test lead to the +5V line, and the black test lead to measure the high and low voltages of the three leads (there is a trick on the usage of the red and black test leads), press 60° and 120 °The commutation table of the motor can be compared. 23. What will happen if a 60° brushless controller is used on a 120° brushless motor? How about the other way around? Answer: It will cause phase loss and cannot operate normally; however, an intelligent brushless controller developed by Tianjin Songzheng can automatically identify 60° motor or 120° motor, so that it can be compatible with the two motors, so that it can be repaired and replaced. much easier. 24. What is the intuitive difference between a brushed high-speed motor and a brushed low-speed motor?Answer: A. High Speed ​​(High Speed) motor has surpassedclutch(Function like a flywheel), turning in one direction is easy, turning in the other direction is laborious; low-speed motors are equally easy to turn in both directions. B. The high-speed (High Speed) motor has a louder noise when it rotates, and the low-speed motor has less noise when it rotates. It is easy for an experienced person to recognize it by ear. 25. How is the starting current of the motor defined? Answer: Generally, it is required that the starting current of the motor cannot exceed 2 to 5 times of its rated current. This is also an important reason why current limiting protection is implemented on the controller. 26. Why are the motor speeds on the market (Rialto) getting higher and higher and what is the impact? Answer: A. The supplier can reduce the cost by increasing the speed. It is also a low-speed motor, the speed (Tempo) is higher, the number of turns of the coil is less, the silicon steel sheet is also saved, and the number of magnets is also less. The buyer thinks that the speed (Tempo) High is good. B. When working at rated speed (Tempo), the efficiency remains unchanged, but the efficiency is significantly lower in the low-speed zone, that is, the starting is weak. C. The efficiency is low, it needs to start with a large current, the riding current is also large, the current limit of the controller is large, and it is not good for the battery. 27. How to repair the abnormal heating of the motor? Answer: The maintenance method is generally to replace the motor or perform maintenance. 28. When the no-load current of the motor is greater than the limit data of the reference table, it indicates that the motor has malfunctioned. What are the reasons? How to repair? Answer: The internal mechanical friction of the motor is large; the coil is locally short-circuited; the magnetic steel is demagnetized; the inverter of the DC motor has carbon deposits. The maintenance method is generally to replace the motor, or replace the carbon brush, and clean up the carbon deposits. 29. What is the maximum no-load current without failure of various motors? Motor type: When the rated voltage is 24V, when the rated voltage is 36V, the side-mounted motor 2.2A 1.8A high speed (High Speed) brushed motor 1.7A 1.0A low speed brushed motor 1.0A 0.6A high speed (High Speed) brushless motor 1.7A 0.6A low speed Brushless motor 1.0A 0.6A (to be continued)