The car generator is a relatively important presence in the car. The synchronous generator works based on the principle of electromagnetic induction. It converts mechanical energy into electrical energy through the relative movement of the magnetic field of the rotor and the stator winding. When the rotor is driven by an external force, the magnetic field of the rotor and the stator conductor move relative to each other, that is, the conductor intersects the magnetic field lines, from so that an induced electromotive force is generated in the conductor and its direction can be determined according to the right-hand rule. So, what are the reasons why the automobile generator is not producing electricity?
What are the reasons why a car generator does not produce electricity: the generator is overheated
(1) The generator does not operate according to the specified technical conditionses. For example, the. the stator voltage is too high and iron loss increases; the load current is too large, and the copper loss of the stator winding increases, which slows down the speed of the cooling fan, affecting the heat dissipation of the generator. ; the power factor is too low, which increases the rotor excitation current, causing the rotor to heat up. Check whether the monitoring instrument indication is normal. If this is abnormal, necessary adjustments and treatments should be made to operate the generator according to the specified technical conditions.
(2) The three-phase load current of the generator is unbalanced, and the overloaded single-phase winding will overheat if the difference between the three-phase current exceeds 10% of the rated current; This is a serious phase current imbalance. An unbalanced three-phase current will produce a reverse magnetic field, increasingthus reducing losses and causing heating of components such as pole windings and ferrules. The three-phase load must be adjusted to keep the current in each phase as balanced as possible.
(3) The air duct is clogged with dust and ventilation is poor, making it difficult for the generator to dissipate heat. Dust and grease in the air duct must be removed so that the air duct is not clogged.
(4) The inlet air temperature is too high or the inlet water temperature is too high and the chiller is blocked. The inlet air or water temperature must be lowered to eliminate blockage in the cooler. Before the fault is cleared, the generator load must be limited to reduce the generator temperature.
(5) Too much or too little grease is added to the bearing. Fat must be added according tont to regulations, generally 1/2 ~ 1/3 of the bearing chamber (the upper limit is used for low temperatures). speed, and the upper limit is used for high speed). lower limit), and must not exceed 70% of the bearing chamber.
(6) Bearing wear. If the wear is not significant, the bearing will overheat locally; if wear is severe, the stator and rotor may rub against each other, causing the stator and rotor to overheat. Bearings should be checked for noise. If friction between the stator and rotor is detected, the machine should be stopped immediately for maintenance or replacement of the bearings.
(7) The insulation of the stator core is damaged, causing a short circuit between the leaves, causing an increase in local eddy current loss in the core and heat generation. In severe cases, the stator winding swill be damaged. damaged. The machine must be stopped immediately for maintenance.
(8) The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat. The machine must be stopped immediately for maintenance.
What are the reasons why the car generator does not generate electricity: abnormal performance
1 When the engine is running or driving normally, the charging indicator light on the instrument continues to light up. up.
Causes of breakdowns and troubleshooting
1. Troubleshooting if the generator drive belt is loose or worn: Adjust or replace the generator drive belt.
Check and adjust the generator drive belt:
p>① Visually inspect the generator drive belt for excessive wear, worn curtains, etc. If there is a problem, replace the generator drive belt.ator.
② Check the tension of the generator drive belt. A drive belt that is too loose will cause slipping, and a drive belt that is too tight will affect the life of the generator bearings. To check the drive belt tension, you can use your fingers to press hard on the drive belt between the two pulleys. If the degree of reduction of the transmission belt is about 10mm, the tension is generally considered appropriate if the amount of reduction; is too great, the tension will be insufficient, resulting in slippage if the drive belt is almost. If there is no reduction, the drive belt is too tight. Adjustments are necessary. 2. Troubleshoot loose wire connections or short circuits: Check wire connections between generator and battery terminals, reinstall and securenuts to wire terminals.
3. Troubleshooting if the main fuse is blown: Replace the main fuse.
4. Internal generator faults usually occur at the voltage regulator. Troubleshooting: Repair the generator.
5. Troubleshooting poor grounding: Check the ground wire between the negative battery terminal and the car body, reinstall and tighten it.
6. The battery is damaged
Home generator does not mark the neutral line?
The reason why the generator cannot send 220V voltage after starting:
1. The excitation circuit is disconnected, preventing the voltage from increasing. Check if the excitation circuit is broken and if the contact is good.
2. The residual magnetism disappears. If the exciter voltmeter does not indicate that the residual magnetism is gone, the exciter must be magnetized.
3. The polarity of themagnetic field coil of the exciter is reversed and its positive and negative connecting wires must be swapped.
4. During some tests during generator maintenance, the magnetic field coil was mistakenly supplied with reverse DC current, causing residual magnetism to disappear or re-magnetize in reverse.
Detailed information:
Other common generator faults and causes:
1. Generator overheating
1. The generator does not comply with regulations. If the stator voltage is too high, iron loss increases; the load current is too large, the copper loss of the stator winding increases; the frequency is too low, slowing down the speed of the cooling fan and affecting the heat dissipation of the generator; The power factor is too flow, which leads to an increase in the rotor excitation current, causing the rotor to heat up. Check whether the monitoring instrument indication is normal. If this is abnormal, necessary adjustments and treatments should be made to operate the generator according to the specified technical conditions.
2. The three-phase load current of the generator is unbalanced and the overheated single-phase winding will overheat if the difference between the three-phase current exceeds 10% of the rated current, which is the case. a serious phase current imbalance and the three-phase current is seriously unbalanced. Unbalanced phase currents will produce a reverse magnetic field, thereby increasing losses and causing heating of components such as pole windings and ferrules. The three-phase load must be adjusted to keep the current in each phase as balanced as possible.
3. The air duct is obstrewn with dust and ventilation is poor, making it difficult for the generator to dissipate heat. Dust and grease in the air duct must be removed so that the air duct is not clogged.
4. The inlet air temperature is too high or the inlet water temperature is too high and the chiller is blocked. The inlet air or water temperature must be lowered to eliminate blockage in the cooler. Before the fault is cleared, the generator load must be limited to reduce the generator temperature.
5. If the bearing is filled with too much or too little grease, grease should be added according to regulations, generally 1/2 ~ 1/3 of the bearing chamber (the upper limit is used for low speeds, and the lower limit lower is used for high speeds) ), and should not exceed 70% of the wheel chamberment.
6. Bearing wear. If the wear is not significant, the bearing will overheat locally; if wear is severe, the stator and rotor may rub against each other, causing the stator and rotor to overheat. Bearings should be checked for noise. If friction between the stator and rotor is detected, the machine should be stopped immediately for maintenance or replacement of the bearings.
7. The insulation of the stator core is damaged, causing a short circuit between the leaves, causing an increase in local eddy current loss in the core and heat generation. In severe cases, the stator winding will be damaged. . The machine must be stopped immediately for maintenance.
8. The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat. The machine must be stopped immediately to maintainnce.
2. There is abnormal voltage between the neutral line of the generator and the earth
1 Under normal circumstances, the air gap under each magnetic pole is caused by the influence of. high order harmonics or manufacturing process. Very low voltage occurs due to unequal magnetic potential. If the voltage is one to several volts, there is no danger and there is no need to deal with it.
2. There is a short circuit in the generator winding or poor insulation from the ground, which causes the performance of the electrical equipment and generator to deteriorate and easily generate heat. It must be repaired in time to avoid. the extent of the accident.
3. There is no voltage between the neutral line and ground when there is no load, but voltage appears when there is a load. This is caused by the imbalance of the three phases. the load must be adjusted to make it fundamentalentally balanced.
3. Generator current is too high
1. The load is too great and the load needs to be reduced.
2. If a phase-to-phase short circuit or ground fault occurs in a transmission line, the line must be inspected and restored to normal once the fault is cleared.
4. The voltage across the generator is too high
1. The voltage of the network parallel to the electrical network is too high. The parallel generator voltage must be reduced.
2. The fault of the excitation device causes overexcitation, and the excitation device should be repaired in time.
5. Insufficient power
Due to insufficient compound excitation compensation of the voltage source of the excitation device, the excitation device cannot provide the required excitation current for the armature reaction , causing the voltage across the generator. be lower than the network voltage. If therated reactive power does not exceed the rated reactive power, the following measures should be taken:
1. Connect a three-phase voltage regulator between the generator and the excitation. reactor to increase the voltage across the generator so that the excitation device The magnetic potential increases gradually.
2. Change the phase of the magnetomotive force of the excitation device voltage and the voltage across the generator to increase the resulting total magnetomotive force. A resistor of several thousand ohms and 10 W can be connected in parallel at both ends of each. reactor phase winding.
3.Reduce the resistance of the rheostat to increase the excitation current of the generator.
6. The generator loses its residual magnetism and cannot generate electricity at startup
1. The generator often loses its residual magnetism after shutdown. This is due to the fact that thematerial used for the excitation poles is close. to mild steel and the residual magnetism is relatively low. When the excitation winding has no current after stopping, the magnetic field will disappear. A battery must be prepared and magnetized before producing electricity.
2. If the magnetic poles of the generator lose their magnetism, a direct current greater than the rated current (for a short time) should be transmitted into the winding for magnetization, i.e. sufficient residual magnetism can be restored .
Baidu Encyclopedia - Generator Failure
Baidu Encyclopedia - Generator
Excuse me, the generator only has the live wire which comes out, then where the neutral wire comes from
Hello:
——★1.We know that the neutral line is connected to ground (the point neutral of the power supply (the power system transformer is grounded) and the live wiren is connected to earth. There is a voltage of 220 V.
——★2.The domestic generator produces two wires A and B, and the rated voltage between the two wires is 220 V Since the output wire (A or B) of a home generator is not connected to ground, there is no distinction between live and neutral wires.
——★3. If you connect one wire (A or B) coming out of the generator to ground, then that wire is called the neutral wire, and the other wire is called the neutral wire. One wire is the live wire, which has a voltage of 220 V to ground.
——★4. For the neutral point grounding device of the transformer, the electrical safety rules are strictly stipulated: the grounding resistance should not be greater than 4 Ω, and the general household installation meets the requirements. It is very difficult and completely unnecessary to ground the grounding post, soNote that domestic generators do not mark the neutral line.
There are two wires coming out of the 220V generator. Connect one to the hull, then ground it. The one connected to the hull and then to ground is the neutral wire. ;
380V generator. The neutral wire starting from the star point neutral wire is the neutral wire, which is connected to the generator shell, ground wire, etc. .
6-10KV is a non-grounding operating system. Directly powered high voltage loads are three phase and do not require a neutral line. There is no neutral line in the angular connection and the neutral line in. there is no need to remove the star connection. If low voltage electricity is supplied and the voltage is reduced by the transformer, there will be a neutral line.