Techniques for determining whether a downed conductor is present in an electrical power distribution network that includes a neutral line and a plurality of energized conductors are disclosed. For example, a sampled neutral current signal is received, the sampled current signal including a plurality of values, each of the values representing an amplitude of current that flows in of the neutral conductor at a particular time; an unfiltered current signal is generated based on the sampled current signal; the sampled current signal is filtered to generate a filtered current signal; the unfiltered current signal and the filtered current signal are compared to generate an error signal; and the error signal is analyzed to determine whether at least one of the plurality of conductors is a downed conductor.

A power supply device includes a power supply circuit, a detection circuit, and a control circuit. The power supply circuit is configured to output a supply voltage. The detection circuit is configured to sequentially provide a first predetermined resistance and a second predetermined resistance according to a plurality of switching signals, in order to operate with an electronic device and the supply voltage to sequentially obtain a first detection voltage and a second detection voltage. The control circuit is configured to generate the switching signals, and determine a load resistance of the electronic device according to the first detection voltage and the second detection voltage. The control circuit is further configured to determine whether the load resistance is within a predetermined resistance range, and the power supply circuit is further configured to drive the electronic device if the load resistance is within the predetermined resistance range.

A power supply device includes a power supply circuit, a detection circuit, and a control circuit. The power supply circuit is configured to output a supply voltage. The detection circuit is configured to sequentially provide a first predetermined resistance and a second predetermined resistance according to a plurality of switching signals, in order to operate with an electronic device and the supply voltage to sequentially obtain a first detection voltage and a second detection voltage. The control circuit is configured to generate the switching signals, and determine a load resistance of the electronic device according to the first detection voltage and the second detection voltage. The control circuit is further configured to determine whether the load resistance is within a predetermined resistance range, and the power supply circuit is further configured to drive the electronic device if the load resistance is within the predetermined resistance range.

In a method and a corresponding device for detecting phase failures in a converter, current regulators of a positive phase sequence system and current regulators of a negative phase sequence system are provided for the current control of the converter, wherein the current regulators of the positive phase sequence system and the current regulators of the negative phase sequence system each have an integrator, resulting, in the case of a network fault, in coupling of the integrators. At least one measured or calculated value is checked by a monitoring unit for a course that is typical of the coupling of the integrators, wherein the monitoring unit generates a fault signal if such a typical course is detected.

The present disclosure pertains to detection of abnormal, risky, or aberrant conditions in a power distribution network and to corresponding trip signals being used to trip open devices such as reclosers upstream of where the abnormal condition is detected. Detection of open phase on a distribution circuit prevents severed conductors from causing a ground fault, therefore avoiding the possibility of fire and dangerous conditions. The voltage unbalance may be measured using an end of line relay that includes an electrical sensor or relay, a tripping mechanism, and a signal transmitter.

The present disclosure pertains to detection of abnormal, risky, or aberrant conditions in a power distribution network and to corresponding trip signals being used to trip open devices such as reclosers upstream of where the abnormal condition is detected. Detection of open phase on a distribution circuit prevents severed conductors from causing a ground fault, therefore avoiding the possibility of fire and dangerous conditions. The voltage unbalance may be measured using an end of line relay that includes an electrical sensor or relay, a tripping mechanism, and a signal transmitter.

A system, apparatus, and method for detecting a fault in a power transmission system containing multiple distribution transformers configured in a loop may include multiple current sensors and at least one processor. A first current sensor may be positioned to sense a primary input current to a distribution transformer and a second current sensor may be positioned to sense a primary output current of the distribution transformer. The processor(s) receives signals representing outputs of the current sensors, determines a value representing a current flowing in a primary winding of the distribution transformer based on the received signals (e.g., the difference between the currents sensed by the first and second current sensors), and generates an alert when the determined value is outside a desired range of values. Current sensors may be installed to monitor at least the primary inputs of all distribution transformers configured in the loop to identify faulty transformer(s).

A system, apparatus, and method for detecting a fault in a power transmission system containing multiple distribution transformers configured in a loop may include a current sensor and one or more processors. The current sensor may be positioned to concurrently sense a primary input current to and a primary output current from a distribution transformer. The processor(s) receives a signal representing an output of the current sensor, determines a value representing a current flowing in a primary winding of the distribution transformer based on the received signal (e.g., the differential current value), and generates an alert when the determined value is outside a desired range of values. A current sensor and a processor may be installed at each distribution transformer in the power transmission system to enable a remote server to directly monitor the primary winding currents of all the distribution transformers in the system to identify any faulty transformer(s).

A method may include receiving, via at least one processor, a first set of data indicative of a fault being present and send a first signal to a breaker based on the first set of data. The first signal may cause the breaker to open a plurality of poles of the breaker. The method may then involve receiving a second set of data indicative of the fault being cleared and sending a second signal to the breaker based on the second set of data. The second signal may cause the breaker to close a first pole of the plurality of poles at a first time and close a second pole of the plurality of poles at a second time different from the first time.

A transmission cable includes a cable body, a return control circuit, and a determining circuit. The cable body has a first end and a second end, and the cable body includes a first wire and a second wire. The return control circuit is located at the second end and configured to selectively electrically connect the first wire to the second wire. The determining circuit is located at the first end, and configured to determine an electrical property of the second wire and output a first signal when the foregoing electrical property is less than a threshold.