New energy vehicle charging methods and common faults.
The pure electric vehicle charging system can be divided into two parts. The charging facilities mainly include charging piles, charging harnesses,
and on-board charging devices, including on-board chargers, high-voltage control boxes, power batteries, DC/DC converters, low-voltage batteries,
and various A variety of high-voltage wire harnesses and low-voltage control wire harnesses, etc.
When the pure electric vehicle power battery is low on power, the main methods are DC fast charging, AC slow charging, and battery replacement.
The DC charging system wiring harness and its interface with the vehicle charging system are shown in the figure:
The wiring harness is arranged separately from the high and low voltages behind the vehicle interface. Terminal 1 and terminal 2 of the high-voltage wiring harness correspond to DC- and DC+ respectively,
and interlocking terminals are added to it. Terminals 1-6 of the low-voltage wiring harness correspond to A- of the AC charging port respectively. , A+, CC2, S+, S- and CC1.
The main purpose of CC1/CC2 is to confirm whether the charging base has been plugged into the gun;
The relationship between A+/A- and S+/S-: When plugging the tram into the gun and starting charging, in order to ensure safety,
a 12V voltage will be output through the low-voltage auxiliary power supply. After successful output, At this time,
their BMS will communicate and transmit data information to each other through S+ and S-. If all indicators are normal according to the process, then the positive and negative currents will be output through DC.
So why do charging failures occur at different times? Others stop charging after receiving a message that the other party cannot charge during communication.
Most of them are caused by the vehicle actively stopping, such as when the weather is hot. The car’s battery temperature was too high.
When the car owner arrived at the charging station to charge, he found that the charging failed. The reason was that the battery was overheated.
When they communicated with the BMS, the car told the charging station that the battery temperature was too high and could not be charged.
At this time, charging When the charging pile receives this message, it will end charging, or if our charging pile sends a message to the vehicle for handshake and does not receive a reply from the vehicle for more than the specified number of times, it will also choose to end charging, etc.
A good solution to this situation is to unplug the charging gun, let the trolley sit for a few minutes, and wait for the battery temperature to drop.
Then we can re-insert the charging gun to start charging. In most cases, charging fails due to false alarms from the battery. At this time, we can re-plug and unplug the gun and scan the code to charge again to try.
Common communication piles do not have so many problems because they have high compatibility and do not have protocol requirements for BMS communication.