20kW EV Charger for DC fast lithium battery Charger AC/DC
Introduction to battery charger
SANDI high power battery charger is developed s pecially by Zhejiang Sandi Electric Co., Ltd. for DC battery sy stem ch arging station. With three phase non neutral conductor AC input, it has the advantages of high efficiency, high power density and low harmonic.
1. Hot plug
Plug technology is applied to the charging module to provide convenience for installation and maintenance. The access of the charging module to the system shall not disturb the output voltage of the system.
2. Advanced current sharing technology
Under constant voltage working mode, the charging modules can share current automatically within 10S, with degree of unbalance less than ±0.5A.
3. Control of input limited power
Refer to Fig. 1-8 for the relation between the output power and input voltage of the charging module. When the input voltage is within 220 Vac ~ 280 Vac (return difference is less than 5V), the module can output the maximum power of 7 KW; when the input voltage is within 90 Vac ~ 220 Vac, the module can still work normally under limited power mode.
4. Control of output constant power
When there is a rated input voltage, the output power of the module is 7KW. Refer to Fig. 1-9 for the relation between the output voltage and the output current of the module.
7.2 The charging module adopts two working modes:
7.2.1) The module receives monitoring instructions and works in 32A mode or 16A mode (with different power limits).
7.2.2) Outputs 150-750V. When there is no required voltage, the power-on defaults to work in the low-voltage section. When the actual output of the module is higher than 525V, the module automatically switches to the high-voltage section. When the demand is lower than 500V, it will automatically switch back to the low-voltage section to work. When the output of the module changes from high voltage to low voltage, the output of the module will drop briefly across the switching point; when the output of the module changes from low voltage to high voltage, there is no drop in the output of the module when it crosses the switching point. When the switching point is crossed, the power output is as above Graph curve way.
7.2.2 Temperature limited power
Under 55°C ambient temperature, the module can output full power of 7kW;
Over 55°C ambient temperature, the module shall be used by derating with the power Linearly .
Under 65°C ambient temperature, the allowable output power of the module is 3,500 W.
Under 75°C ambient temperature, the output power of the module is reduced to 0.
7.2.3 Regulation of output current limiting point
The module has stepless current limiting function. Through the external monitoring module, the current limiting point of the module is adjustable in the range of 0~20A. When the output voltage is between 150Vdc 750Vdc,
When, the current limiting accuracy of the module is ±0.3A.
7.2.4 Regulation of output voltage
The output voltage of the module can be regulated constantly through the external monitoring module, with regulation range of 150Vdc ~ 750Vdc and minimum regulation step of 0.1 Vdc.
7.2.5 Fan control
The built-in processor of the module can regulate the speed of the fan according to the internal temperature and output current of the module.
7.2.6 Protection of input overvoltage/ voltage shortage
The input of the module is a single-phase AC voltage. When the input voltage is lower than 90Vac or greater than 280Vac, the module will stop working and no output.
When an overvoltage or undervoltage alarm occurs, the module will report the alarm information to the monitoring module; when the input voltage returns to the normal range, the alarm disappears and the module recovers Return to normal working condition.
7.2.7 Output overvoltage protection
Manual intervention is required after overvoltage protection to boot.
The software overvoltage protection point can be set through the monitoring module, the setting range is 150Vdc 778Vdc, and the factory default value is 778Vdc.
Manual intervention method: The module can be reset through the monitoring module, or the module can be reset by re-powering after the AC power failure.
6.2.8 Over-temperature protection
The environmental over-temperature protection point is 80°C. When the DC panel has a temperature over 85°C, the module will stop working; when the DC panel has a temperature below 75°C, the module will automatically work again.
6.2.9 Protection of internal bus fault
When the internal bus voltage of the module is beyond the overvoltage/ voltage shortage protection point, the module will be powered off automatically. At this time, there is no output from the module and the fault indicator light is on.
6.2.10 Short circuit protection
In case of short circuit of the module, it will be subjected to protective shutdown and the red indicator light of the panel is on, and this condition will be transmitted to the monitor of the “module fault”.
6.2.11 Interruption of background communication
After module communication interruption, the protection indicator light will flash and the module will be subject to shutdown protection. When the communication is recovered, the protection indicator light recovers to normal state and the module works again.
6.2.12 Protection against fan fault
In case of module communication interruption over 8S, the module will be subject to shutdown protection, without voltage output and the protection indicator light will flash. After fault removal, the module will work automatically again.
6.2.13 Monitoring performance
The charging module is equipped with CAN bus. It can also be converted to RS232 via the protocol converter, and the RS485 protocol communicates with the external monitoring module.