Integrated type step-down power supply device and wellsite power supply system

A wellsite power supply system comprising:

• a step-down power supply device;
• one or more electric drive fracturing devices connected to the step-down power supply device via a frequency converter sled;
• and
• an auxiliary device,
• wherein the step-down power supply device comprises:
• a first switch cabinet configured for receiving an alternating current having a first voltage and controlling on-off switching of a power supply network;
• a transformer configured for receiving the alternating current from the first switch cabinet, reducing the first voltage of the received alternating current to a second voltage, and outputting the second voltage;
• a second switch cabinet configured for receiving the second voltage from the transformer and outputting the second voltage;
• and
• a radiator configured for dissipating heat of at least two of the first switch cabinet, the transformer, and the second switch cabinet,
• wherein the first voltage is greater than the second voltage;
• wherein a voltage for driving the auxiliary device is less than a voltage for driving the one or more electric drive fracturing devices;
• and
• wherein the frequency converter sled is integrated with one or more frequency converters, and each of the one or more frequency converters is configured for driving at least one electric drive fracturing device or at least one auxiliary device.