The invention discloses a
reverse connection prevention circuit for a
direct current power supply. The circuit comprises a polarity detection module, a
relay and a
contactor, wherein the polarity detection module is connected between the positive and negative input ends of the
direct current power supply, and is used for detecting the normal connection or
reverse connection of the
direct current power supply, and outputting a corresponding
signal; one end of a coil of the
relay is connected with the output end of the polarity detection module, and a contact of the
relay is connected in series with a coil of the
contactor; and a main contact of the
contactor is connected in series between the positive input end of the direct current power supply and a load. The circuit is safe, reliable and particularly effective to a high-power direct current
system, and can be directly applied to an energy bidirectional flowing direct current power
system to solve the problem of reverse polarity connection of the
system, and the loss of system efficiency is avoided.