There are more than 400 domestic complete vehicle enterprises, and the technical level of each complete vehicle factory is different from that of others. The new energy vehicles put on the market now also have frequent failures. So what are the main problems of new energy vehicles? The whole vehicle is out of power and the charger is not charging. How can we eliminate the source of these new energy vehicle faults? Let me introduce it to you today.
Exclamation mark fault
1. Cause of fault
Generally, after the hardware problem is eliminated, the fault is mostly caused by software and system calibration. The reason is that the system detects that the battery temperature exceeds the preset safety value, or the system detects an occasional fault signal, which limits some functions of the vehicle at its own discretion.
2. Response plan
Just like the solution to computer crash and phone jam, restarting can solve most problems. In fact, a pure electric vehicle can also be regarded as a large electronic product. The power supply of all electronic systems and the main engine is provided by the small battery in the engine compartment.
At this time, just use a wrench to unscrew the negative pole wire of the small battery and keep it disconnected for about 5 minutes, so that the vehicle on-board system is completely powered off, and then tighten the negative pole wire of the small battery to restore it.
At this time, the system of the vehicle can be regarded as "restart" after the power is cut off. All calibration and detection are restored to the initial value. At this time, restarting the vehicle can almost be successful.
Power battery insulation fault
Possible causes: water ingress into the battery box or plug-in of the electric vehicle, leakage of the battery cell, high ambient humidity, insulation misinformation, and poor insulation of other high-voltage components (controller, compressor, etc.) of the vehicle.
Treatment method: if the positive pole is to the ground, if the voltage or insulation resistance is less than the specified value, the negative pole circuit will be sentenced to leakage; If the voltage or insulation resistance of the negative pole to the ground is less than the specified value, the positive pole circuit will be sentenced to leakage. The leakage point can be calculated by dividing the leakage voltage by the single string voltage at this time, and then analyzed and handled according to different situations.
Power limit light is on
This is the common "tortoise light" of car owners. The fault phenomenon is that the output power of the vehicle is limited, and the vehicle can only drive at the speed limit of 40 km/h.
1. Cause of fault
There are several reasons for this phenomenon. In addition to the non fault reason that the power battery is about to run out and the vehicle enters the protection state, the most important thing is that the system detects that the vehicle has a fault in the circuit system, or the power battery temperature exceeds the safety range, and the power needs to be reduced to ensure the safety of relevant vehicle components.
2. Response plan
If the tortoise lamp appears due to power loss of the power battery, it can be solved by finding a place to charge as soon as possible; If the temperature of the battery is too high, it is recommended to find a place to stop the engine temporarily, and continue driving after the battery recovers to a safe temperature; If the driver is in a hurry and can confirm by himself that the vehicle has no other faults, he can stop temporarily, disconnect the negative pole of the small battery in the engine compartment, restart the vehicle and "flush out" the previous fault warning record.
If the tortoise lamp cannot be turned off after restarting or cooling for a long time, and the power battery is confirmed to be fully charged, it is better to contact for repair.
Power battery temperature fault
1. Excessive temperature difference of battery
Possible cause: The plug of the cooling fan is loose, and the cooling fan is faulty.
Troubleshooting: Unplug the fan plug cable again; Supply power to the fan separately and check whether the fan is normal.
2. Battery temperature too high or too low
Possible causes: the plug of the cooling fan is loose, the cooling fan is faulty, and the temperature probe is damaged.
Troubleshooting: Unplug the fan plug cable again; Power the fan separately and check whether the fan is normal; Check whether the actual temperature of the battery is too high or too low; Measure the internal resistance of the temperature probe.
3. The motor produces a large amount of sparks, local overheating and shaking
Possible causes:
Short circuit caused by water ingress of the motor burns the motor;
The overload operation of the motor causes the commutator to burn out due to short circuit, and the phenomenon is that the commutator turns black.
Abnormal noise of motor
Possible causes:
The concentricity of motor and rear axle connection does not meet the standard;
The brush is not well connected with the commutator, which needs to be corrected and adjusted;
The bearing on the rotor inside the motor is damaged and needs to be replaced.
Power battery failure
Power battery failure (except for the failure of parts themselves, if the display and acquisition modules are abnormal, the failure does not actually occur)
Common battery faults can be viewed in MP5, such as ① battery equalization fault, single cell voltage ultra-high or ultra-low fault, etc. When this type of fault occurs, the single power battery voltage value can be viewed through the instrument LCD screen to see whether there is a level 1 fault: the voltage value of single or multiple batteries is greater than 3.85V or less than 2.5V; Level II fault: voltage value of single or multiple batteries is greater than 3.75V or less than 2.7V; Level III fault: voltage of single or multiple batteries is greater than 3.65V or less than 2.8V. ② The single battery temperature is too high or too low. In case of this type of fault, the maximum and minimum values of the single power battery temperature can be checked through the LCD of the instrument. Whether there is a level 1 fault: the maximum temperature is greater than 75 ℃; Level II fault: the maximum temperature is more than 70 ℃, and the minimum temperature is less than 0 ℃; Level III fault: the maximum temperature is more than 60 ℃, and the minimum temperature is less than 5 ℃. ③ For battery insulation level fault, the current insulation resistance value can be checked by using the battery information LCD screen to see if there is a level 1 fault: the insulation resistance is less than 500K Ω; Level II fault: insulation resistance is less than 300K Ω; Level III fault: insulation resistance is less than 100K Ω.
In case of type ① failure, determine the number of battery box in which the single battery is located, unpack and replace the battery. At present, such failures are handled by after-sales personnel of the battery manufacturer; In case of type ② fault, the temperature shall be restored to the normal range before use; In case of type ③ fault, insulation detection meter shall be used to test the insulation value of all high-voltage connecting wires with 1000V test gear. Normal insulation is more than 1G Ω. In case of abnormal value, it is necessary to confirm whether there is a problem with the wiring harness insulation or the high-voltage consumer connected to the wiring harness has insulation fault.
Electrical equipment does not work
The main electrical equipment of electric vehicles include various lamps (front combination lamp, measuring lamp, reversing lamp, rear combination lamp, etc.), radio, top fan, vacuum pump, wiper, combination instrument, electric power steering gear, air conditioner, etc. During field commissioning, radio, vacuum pump, combination instrument and wiper often fail to work. The abnormal operation of electrical equipment mainly refers to the inconsistency between the working state and the design state, such as the continuous pumping of the vacuum pump, the abnormal display of the combination instrument, and the great interference of the radio.
Analysis and Treatment of Electrical Equipment Failure
