Abstract: Methods and apparatuses are disclosed for detecting a fault in an electrical power system having three phases, a plurality of feeders, a ground, a neutral, and a neutral resistor electrically coupling the neutral to the ground. In one embodiment, the method may comprise determining a neutral current in the neutral resistor; measuring a net feeder current for each of the plurality of feeders; and setting a state of a feeder fault output signal based on the neutral current and the net feeder current for at least one of the plurality of feeders.

Abstract: A method and apparatus are disclosed for determining a system charging current in an electrical power system having three phases, a ground, a neutral, and a neutral resistor electrically coupling the neutral to the ground. The method comprises: measuring a line voltage of each phase; measuring a line-to-neutral voltage of each phase; determining a charging capacitance of each phase based on the line voltage of each phase, the line-to-neutral voltage of each phase, a frequency of the electrical power system, and a value of the neutral resistor; determining a phase charging current for each phase of the electrical power system based on the charging capacitance of each phase, the line voltage of each phase, and the frequency of the electrical power system; and determining the system charging current based on the phase charging current for each phase.

Abstract: An improved load bank system is provided. In one embodiment, the system includes control circuitry configured to provide duty cycle commands corresponding to a desired load. An input is configured to receive power from an electrical power system to be connected to the load bank system. At least one power resistor is selectively connected to the input. High speed solid state electronic switching circuitry is configured to rapidly switch according to the duty cycle command from the control circuitry in order to rapidly and sequentially permit current flow and prevent current flow through the resistor according to the duty cycle command. The effective resistance presented to an electrical power system to be connected at the input is thereby modified. Other load bank systems and load bank units are provided, as well as computer implemented and other methods for controlling a load bank system.