Power supply device and power supply system for server rack

A power supply system comprising:

• a server rack comprising a bottom plate;
• a power supply assembly attached to the server rack in a first direction substantially parallel to the bottom plate;
• and
• a power supply device comprising:
• a main bus-bar assembly electronically connected to the power supply assembly and comprising a first main bus-bar and a second main bus-bar attached to the first main bus-bar;
• an assistant bus-bar assembly comprising a first assistant bus-bar and a second assistant bus-bar attached to the first assistant bus-bar;
• and the first assistant bus-bar being electronically connected to the first main bus-bar, and the second assistant bus-bar being connected to the second main bus-bar;
• and
• a plurality of connectors being electronically connected to the assistant bus-bar assembly;
• each of the plurality of connector comprising a first pin and a second pin;
• wherein the first pin is engaged with the first assistant bus-bar, and the second pin is engaged with the second assistant bus-bar;
• wherein the assistant bus-bar assembly is attached to the server rack in a second direction substantially perpendicular to the bottom plate, and the plurality of connectors are arranged on the assistant bus-bar assembly in the second direction.