Limited short-current, bi-directional power flow and variable operating modes in microgrids make for relay’s malfunction and false tripping. A fault detection method which starts by voltage dip and scans the largest positive-sequence fault component is explored. A comprehensive scheme using the method and differential protection is proposed for radial microgrid. The scheme is independent of amplitude of short-current, without setting current threshold, working well in both paralleled and islanded modes. Even coming across failure of communication, the scheme is still effective. Simulations in PSCAD verifies the proposed scheme.