This invention discloses a multifunctional
portable power distribution box and its usage method, belonging to the field of
power management and power distribution protection technology. The box includes: S1, setting up an intelligent power distribution host, wherein the intelligent power distribution host comprises a sealed
metal shell separating an upper sensing and analysis compartment and a lower power execution compartment; a main controller and a high-frequency electrical parameter sensor are installed in the sensing and analysis compartment, and a multi-channel
solid-state
relay array is installed in the power execution compartment; S2, the main controller estimates the load components online and constructs a
load profile, wherein the AC cycle is locked by the
voltage zero-crossing point collected by the high-frequency electrical parameter sensor, and the instantaneous power curve within the cycle is calculated. This invention can identify the type of connected load, and based on the power contribution of the instantaneous power curve in the in-phase power region, the lagging power region, and the peak
impact region, the proportions of resistive, inductive, and nonlinear components of the load are calculated in reverse, providing a basis for customized protection strategies.