1. The capacity of the transformer to be selected for the car charging station can be calculated by the following formula:
The total load required by the charging station = the total output power of the charging pile / average efficiency / line and reactive loss coefficient / charging machine simultaneous utilization coefficient efficiency (average efficiency 0.9, line and reactive loss coefficient 0.9, charging machine simultaneous utilization coefficient efficiency 0.85).
For example: A charging station has 10 charging piles, each of which is 120KW, so how big a transformer is needed?
Calculation: The total load required by the charging station = (10120) / 0.9 / 0.9 * 0.85 = 1259KVA
Conclusion: Configure a dry-type amorphous transformer of not less than 1259 KVA and use the DYn11 wiring method.
2. Cable square specification
The cable is the medium for high voltage to be introduced into the box transformer, and it is also the only connection method between the charging pile and the box transformer. Therefore, the cable model is particularly important. There are different cable models for high voltage access and low voltage routing to transmit electrical energy and provide power supply services for charging vehicles.
The cables used by different chargers vary greatly, not only in terms of the transmission capacity of the cables, but also in terms of the prices of the cables. In the combination of different mechanical equipment, the matching of the cables will also be one of the most obvious outputs in the investment cost, and the price of the cables will depend on market fluctuations. Cables cannot be equipped arbitrarily, not only to ensure the normal output of the charger, but also for the safety of the station. Reasonable matching can bring an efficient working environment and a safe and long-term charging station.