Methods and apparatus to implement safety applications associated with process control systems are disclosed. An apparatus includes a configuration controller to: provide a plurality of available safety applications for implementation by a safety trip device to a user for selection, a first one of the safety applications associated with a first set of I/O signals, a second one of the safety applications associated with a second set of I/O signals, the first safety application implemented based on first pre-programmed instructions stored in memory of the safety trip device, the second safety application implemented based on second pre-programmed instructions stored in the memory; and, in response to a user selection of the first safety application, prompt the user to specify values for configuration settings associated with the first safety application. The apparatus also includes an I/O analyzer to implement the first safety application.

Real-time detection of high-impedance faults in a distribution circuit is described. The real-time detection of high-impedance faults includes two steps. First, adaptive soft denoising is employed to perform a filtering process on a healthy dataset, and to determine a threshold. This reduces the rate of false alarms. Second, faulty datasets are prefiltered via adaptive soft denoising, then the denoised signals are processed via discrete wavelet transform to perform high-impedance fault detection using the threshold.

A disclosed under-voltage lockout (UVLO) circuit includes an automatic UVLO threshold configuration. The UVLO circuit may include an over-voltage protection circuit that receives power from a power source, a peak detector that detects a peak voltage output for the power source, a voltage threshold generator that sets a UVLO threshold based on the peak voltage output, and a comparator that compares an instantaneous voltage with the UVLO threshold and configures an operating mode of a device based on the comparison.

One example includes a power generator protection system. The system includes a circuit breaker configured, when triggered, to provide an open circuit in a power line configured to conduct a current between a power grid point-of-interconnect (POI) and a power generator system. The system also includes a programmable controller configured to monitor the current and to generate a dynamic current threshold based on the current. The programmable controller can further be configured to compare the current with the dynamic current threshold and to trigger the circuit breaker based on a difference of the current relative to the dynamic current threshold to set an arc flash incident energy level of the power generator system at or below a predetermined safety level.

A control system and method for sectionalizing switches and pulse-testing interrupter/reclosers in a distribution grid feeder which enables fault location, isolation and service restoration without requiring an external communications infrastructure to pass information between the switches. The method includes switches entering an armed state when they experience a high fault current during an initial fault event. Then, when the interrupter/recloser runs its test pulse sequence, any armed switch counts all test pulses as fault pulses, while non-armed switches count the test pulses as load pulses. Switches open to isolate the fault based on threshold values of fault pulse count and load pulse count. When an initially active interrupter/recloser completes its test pulse sequence, another interrupter/recloser begins its sequence, and all switches reconfigure their threshold values based on the new interrupter/recloser. Interrupter/reclosers after the initial device use a fast close-open event if necessary to arm some switches for proper fault-count opening.

A control system and method for sectionalizing switches and a source interrupter/recloser in a feeder, or portion of the distribution grid, which enables fault location, isolation and service restoration without requiring a communications infrastructure and communications equipment at the switches. The method includes each switch adaptively configuring fault-count, load-count and voltage-count thresholds upon which the switch should open. The thresholds for each switch are based on the switch's proximity to the active feeder source, which requires a determination of which source is powering the feeder at a particular time. Five different methods are disclosed to determine which source is active. When a fault is detected, the source interrupter/recloser opens and then begins a pulse testing or reclosing sequence, where the switches open to isolate the fault when reaching their fault-count or voltage-count threshold. When the fault is isolated, the source recloses to restore power to unaffected portions of the feeder.

A reclosing fault protection device detects a partial bypass state. Upon detecting the partial bypass state, the fault protection device implements a ground trip delay operating state. The ground trip delay operating state provides a delayed ground trip response characteristic.

A receptacle including an electronic processor configured to receive information from an external load and determine, from the information, an operation profile of the external load. The electronic processor analyzes a present operation of the external load and discontinues power to the external load when a present operation of the external load differs from the operational profile.

A switch circuit includes a first switch, a current protection component, a current detection circuit, and a controller. The first switch conducts a primary side coil. The current protection component generates a detection voltage. The current detection circuit outputs a protection voltage. When the detection voltage is not greater than a first threshold, the current detection circuit generates a first voltage corresponding to the detection voltage as the protection voltage. When the detection voltage is greater than the first threshold, the current detection circuit generates a second voltage corresponding to the detection voltage as the protection voltage, where the first voltage is different from the second voltage. The controller is suitable for making the first switch selectively conducting and not conducting. When the protection voltage is greater than a second threshold, the controller does not increase a proportion of a conduction time to a non-conduction time of the first switch.

A circuit may include an electronic switch that has a load current path coupled between an output node and a supply node and that is configured to connect or disconnect the output node and the supply node in accordance with a drive signal. Further, the circuit includes a monitoring circuit that is configured to receive a current sense signal, which represents the load current passing through the load current path, and that is further configured to determine a protection signal based on the current sense signal, a state of the monitoring circuit, and at least one wire parameter. The wire parameter characterizes a wire that isduring operationconnected to the output node, and the protection signal is indicative of whether to disconnect the output node from supply node. Further, the circuit includes a protection circuit connected to the monitoring circuit.