Power solution of DC charging pile

一． Power system schematic diagram

图1：Power system schematic diagram

     The Wenlida supply parts, high end portable battery power pack, DC voltage up to 345Vdc, low voltage for the external interface of DC, rated voltage 240Vdc, DC/DC leads, auxiliary power to take power from the high voltage side, power supply range allowed is 127 370Vdc, as long as the voltage range high voltage or low voltage end in this interval can be normal work.
S1 is a high voltage DC switch, S2 is a low-voltage DC switch, and S3 is a auxiliary power switch. It is noted that the DCDC module has a 60uF capacitor at the high voltage end and a 100uF capacitor at the low voltage end. The impact current may be generated when the charge is switched to S1 and S2.
Close to S3, complete the supply of power to DCDC, set up a start switch to realize one key start stop.
RS485 bus is reserved for external communication, sending data to external or receiving instructions of control system. DC/DC has external input power accumulation and output power accumulation, and accumulative data has power saving function.

二． External charging mode

Figure 2: external charging

When charging externally, the DC/DC works on the buck mode. The energy flows from the 345V battery pack to the charging pile, and the energy is exported to the outside. The charging mode is constant current and constant voltage two stage, constant current and constant voltage can be set.

三． DC/DC electrical parameters

四． Protection function

1. high voltage end overvoltage, undervoltage protection, low pressure end overvoltage, undervoltage protection;
2. overheating protection, overcooling protection, sampling abnormal protection;
3. high pressure end overcharging and overlaying protection.
4. low pressure end overcharging and overlaying protection.
5. over current protection;
6. system abnormal trip protection.