Why does the motor suddenly heat up, and does the motor generally heat up?

The wiring method of the motor is determined before leaving the factory, and it generally cannot be changed, unless it is changed when the star delta starts, and the triangle connection is still in operation.

Star connection: The coil voltage is 220

Triangular: The coil voltage is 380

The Y-shaped joint and the star joint are the same, but the way of representation is different.

The difference in power between the two connections is about double, and the difference in current is also so large. If Y is connected to the power supply, the motor will generally be burned off (if it is not burned out, it will also lose the layer of skin - patent leather). Generally, the motor should have a wiring indicator diagram in the junction box.

Why does the motor suddenly heat up?

The motor has three coils and six heads, respectively, the star type is that the three coils are linked with one head and three power supplies, and the remaining one tap is linked to each other. For example, U1 is connected to phase A, V1 is connected to phase B, W1 is connected to phase C, and U2, V2, and W2 are shorted together.

A triangle is a triangle where three coils are connected end to end to form a triangle. Then the three nodes are connected to the power supply separately. For example, U1 and W2 are connected to A, V1 and U2 are connected to B, and finally W1 and V2 are connected to C.

In the star connection, the voltage at both ends of each coil of the motor is the phase voltage of the power supply, that is, 220V.

In the triangular connection, the voltage at both ends of each coil of the motor is the line voltage of the power supply, that is, 380V.

The motor suddenly heats up, the possible reasons are: the power supply is out of phase. The motor bearing is loose and the motor vibrates.

The load is too large or the motor is stalled. The power supply voltage decreases, the motor current increases, and so on. Of course, if you use the star connection method when the motor is designed, and now it becomes a triangle connection, the motor will not heat up normally.

It heats up when it runs. No more than 60 degrees.

There are three main categories of causes of hot electric vehicle motors: motor internal failure, controller failure and braking system failure.

Clause. 1. Internal fault of the motor. The internal fault of the motor may cause the motor to heat up due to the following reasons: 1. Caused by the bearing, the bearing carries the rolling speed, once the gap between the steel balls increases, it will cause the internal sweep of the motor, the stator rubs the rotor, the heat is laborious, the friction increases, and the temperature rises.

Solution: Replace high-quality bearings. 2. Caused by stator deformation.

In order to reduce costs, some motor manufacturers have poor stator rigidity and easy deformation, and they will deviate from the normal track when they rotate, and the force will be uneven and the temperature will rise. Solution: Replace the stator with good rigidity.

3. Caused by the coil. Pure copper wire winding, not only saves power but does not heat, and has strong power, but the market appears motor copper-clad aluminum, aluminum-clad copper, which will cause the temperature of the motor to rise. The heating of the motor is also related to the thickness of the motor turn, the internal material of the coil is different, the power, electricity consumption, and the heat will also be different, the thinner the line, the greater the heat.

Solution: Replace the pure copper stator.

Clause. Second, the braking system problem. The heating of the friction motor of the electric vehicle braking system may be caused by the following faults: 1. The brake line does not return.

Due to long-term use, water and rust at both ends of the brake line or scratching the outer skin of the brake line at the bottom end will make the brake not return, accompanied by the brake, and the motor temperature will rise. 2. The brake pads are worn out. Some customers have ineffective brakes, tight and tight, tight to the end, resulting in increased friction between the brake and the motor and the increase in motor temperature.

3. The brake spring is broken. It is difficult to make the brake pads pop in place by relying on the external spring, and the brake pads are not "closed", so that the brake brake brake promotes rolling resistance and increases the temperature of the motor.

Clause. 3. Controller issues. The controller regulates the speed of the motor with the help of electrical energy conversion current. Heating is a normal phenomenon, and both the motor and the controller have a large current passing through during the working process, and the heat must be dissipated through the shell.

No heat means that it is not normal, but there is a problem with overheating, the controller controls the current size, and when overloaded riding or the car is riding, it will also increase the temperature of the motor. However, if there is a fault inside the controller, it will also cause the motor to heat up. In addition, the mismatch between the controller and the motor will also cause heating, the motor small controller will cause damage to the motor, and the power of the control small motor will be insufficient, so it is recommended to use the controller for how big the motor is.

In the process of motor repair and maintenance, the causes of motor heating are summarized, and I hope to bring some guidance to the majority of motor users.

Clause. First, the main reason for the heating of the motor is that the working time is too long, which is like the human body working for a long time, there will be fatigue, the motor is also the same in a long time, the high-intensity use of the motor, it will cause the body of the motor to heat and hot, and seriously will lead to the phenomenon that the motor can not work normally.

Clause. Second, the cooling fan does not work normally during the use of the motor, and in this case, the motor heats up, so in this case, the maintenance personnel of the motor are required to clean the cooling fan of the motor to make the fan work normally, which can reduce the frequency of motor heating.

The performance of the motor is not good, the power conversion efficiency is low, and a lot of electric energy is lost in the form of thermal energy. The possible problems of the motor are: the low height of the motor magnet, the low magnetic flux of the magnetic steel grade, and the small amount of copper of the motor lead to the small regenerative electromotive force and the large current, and because the diameter of the motor copper coil is small, the copper loss is large, and the heat energy is generated.

In short, this is the result of the manufacturer's consideration of cost-saving materials. Of course, the above premise is that you have not increased the current limit of the controller without authorization, and the premise is to rule out the short circuit phenomenon of the motor coil winding.

Normally, the motor is hot for a period of time in the summer! As long as it doesn't exceed 100 degrees, it's no problem! Check if there is a problem with the brake, check whether the motor bearing is broken, and check whether the output current of the controller is too large!

Whether the distance is too far or whether it is overloaded, the above reasons will cause the motor to heat up!

Possible causes of motor heating and slower speed:

1. The system voltage is too low, or the starting motor is low voltage, resulting in slow speed and high temperature.

2. The internal short circuit of the motor wire pack will directly cause the motor to heat up and slow down the speed.

3. The motor rotor is broken and the motor is overheated.

4. The motor is overloaded, and sometimes, the motor load is too heavy.

5. Check whether the 3-phase voltage is balanced and error-free.

6. Whether the gap between the motor bearings is too large and whether there is a lack of oil, the lack of oil will lead to insufficient lubrication and slow speed.

When the motor is running, the electromagnetic eddy current generated by electromagnetic induction acts on the core, which will heat the motor

There are 21 reasons why an electric motor can generate heat:

1. The room temperature is too high.

2. Poor heat dissipation.

3. Overload. 4. Overvoltage and undervoltage or voltage imbalance.

5. Frequent start and stop or frequent forward and reverse rotation.

6. Lack of phase. 7. The fan is broken or the air inlet and outlet are blocked.

8. The bearing lacks oil.

9. The machine is stuck and blocked.

10. The moment of inertia of the load is too large, and the starting time is too long.

11. Inter-turn short circuit.

12. The internal wiring of the new motor is incorrect.

13. The star triangle wiring is wrong.

14. The star-delta or self-coupling step-down starting load has a long restart time or is not converted normally due to fault.

15. The motor is damp.

16. The rotor of the squirrel cage asynchronous motor is broken.

17. The rotor winding of the wound asynchronous motor is broken or the resistance is unbalanced.

18. a rotor sweep.

19. The harmonics of the power supply are too large, such as large rectifier equipment and high-frequency equipment nearby.

20. The magnetic flux of the core of the motor for multiple repairs is reduced.

21. Some motors have poor winding technology.

Analysis method of the cause of motor heating failure:

When analyzing the heating fault of the motor, use a non-contact infrared thermometer, or the temperature measurement gear of the multimeter (multimeter with temperature measurement) to measure the temperature of the end cover of the motor when it exceeds the ambient temperature of more than 25, indicating that the temperature rise of the motor has exceeded the normal range, and the temperature rise of the general motor should be below 20.

The direct cause of the heating of the motor is due to the high current. The relationship between the motor current i, the input electromotive force e1 of the motor, the induced electromotive force (also called the back electromotive force) e2 of the motor rotation and the motor coil resistance r is: i = (e1-e2) r, i increases, indicating that r becomes smaller or e2 decreases.

R getting smaller is generally caused by a short circuit or an open circuit in the coil. The reduction of e2 is generally caused by the demagnetization of the magnet or the short circuit of the coil

caused by open circuits. In the maintenance practice of electric vehicles, the way to deal with motor heating faults is generally to replace the motor.

1. The power supply voltage is too high: when the power supply voltage is too high, the back electromotive force, magnetic flux and magnetic flux density of the motor will increase. Since the magnitude of the iron loss is proportional to the square of the magnetic flux density, the iron loss increases, resulting in overheating of the core.

2. The power supply voltage is too low: when the power supply voltage is too low, if the electromagnetic torque of the motor remains unchanged, the magnetic flux will decrease, the rotor current will increase accordingly, and the load power component in the stator current will increase accordingly, resulting in an increase in the copper loss of the winding, resulting in overheating of the stator and rotor windings.

3. Asymmetry of power supply voltage: if the corner head of the starting equipment is burned and the one phase is not connected, it will cause the three-phase motor to go single-phase, resulting in the overheating of the two-phase winding through the high current and burning out.

4. Three-phase power supply is unbalanced: When the three-phase power supply is unbalanced, the three-phase current of the motor will be unbalanced, causing the winding to overheat.

5. The mechanical load is not working normally: although the equipment is matched, the dragged mechanical load is not working properly, the load is large and small during operation, and the motor is overloaded and heated.

6. Motor winding break: When there is a phase winding in the motor winding, or a branch in the parallel branch is broken, it will lead to three-phase current imbalance and overheat the motor.

7. Wrong motor connection: when a coil, coil group or one-phase winding is reversed, the motor is overheated.

1.The ambient temperature is too high. The inverter is made up of a myriad of electronic components and generates a lot of heat when it works, especially when the IGBT works at high frequencies.

If the ambient temperature is too high, the temperature of the internal parts of the drive will also be too high. To protect the internal return of the drive, the drive will report a high temperature fault and stop the machine. Workaround:

Reduce the temperature in the area where the inverter is located, such as installing forced cooling measures such as air conditioners or fans.

2.The inverter is poorly ventilated. If the air duct of the inverter itself is blocked or the air duct of the control cabinet is blocked, it will affect the internal heat dissipation of the inverter and cause the inverter to overheat the alarm. Solution: Regularly overhaul the inverter, remove the garbage in its air leakage, and clear the ventilation duct.

3.The fan is stuck or damaged. When the fan of the inverter is broken, a large amount of heat accumulates in the inverter and cannot be dissipated. Solution: Replace the fan.

4.The load is too heavy. When the inverter is overloaded (small horse-drawn cart), excessive current and a lot of heat will be generated, and sometimes the inverter will overheat and give an alarm. Solution: Reduce the load or increase the capacity of the drive.

It is normal for the motor to rise when it is working, and the temperature rise of Huizhao motor should not be 85 degrees. Motors that work in a short period of time and heat up rapidly may have the following situations: 1. The power supply voltage is low.

2. Short-circuit between winding turns.

3. The load of renting Bibi is too heavy.