Systems and methods to detect that a protective device is operating outside of a time inverse overcurrent tolerance region are described. For example, a central monitoring station may obtain a time inverse overcurrent tolerance region of a protective device on a power line. The central monitoring station may obtain a fault magnitude measurement and a fault duration measurement of a wireless line sensor on the power line. The central monitoring station may determine that the protective device is operating outside of the tolerance region based at least in part on the fault magnitude measurement and the fault duration measurement. The central monitoring station may provide a signal indicating that there is a potential issue with the protective device.

An arc detection circuit includes a current detector and arc determination unit. The current detector detects a current flowing through a transmission line which connects an electric power supply device and an electric power conversion circuit. The arc determination unit calculates, from a result of measurement of the current, an area of interest and an area for comparison. The area of interest is an area of a region of interest defined by a predetermined frequency range and predetermined time for determination. The area for comparison is an area of a portion in which detected strength exceeds a predetermined strength threshold in the region of interest. The arc determination unit determines an electric arc has occurred when a ratio between the area of interest and the area for comparison exceeds a predetermined area-ratio threshold.

A method for testing capacitive current switching of a circuit breaker, including: realizing a capacitive current switching by the circuit breaker, measuring voltage at the terminals of the circuit breaker after the capacitive current switching, calculating the gradient of the measured voltage, determining whether there is at least one point of gradient whose amplitude exhibits an absolute value greater than a first predetermined threshold, and when such a point is determined, identifying the instant of appearance of the determined point and of the amplitude of variation of the voltage at that instant, as voltage drop.

Systems and method for automated self-testing of a protective device for a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit may include a DC blocking component, a switch assembly, and a spark gap assembly each positioned in parallel between the transformer neutral and ground, a switch assembly. The system may further include various testing circuits configured within the protection circuit and switches which when actuated inject a signal to test various components in the protective device.

A thyristor valve test system based on cooperation of logic functions of software, wherein the test system comprises: a thyristor valve (5) to be tested, a VBE (3) and a tester (4), and the VBE (3) has a dedicated test mode, the tester (4) provides three steps for each test item. The thyristor valve (5) to be tested and the VBE (3) are connected by optical fibers (1), and the thyristor valve (5) to be tested and the tester (4) are connected by cables (2), and there is no connection between the VBE (3) and the tester (4).

Circuit interrupters with opto-electronic and/or acoustic systems that can measure displacement over time, optionally along with interrupt current measurements, during an opening and closing event with signal data collected when triggered by a “breaker open” or “breaker close” event.

Circuit interrupters with opto-electronic and/or acoustic systems that can measure displacement over time, optionally along with interrupt current measurements, during an opening and closing event with signal data collected when triggered by a “breaker open” or “breaker close” event.

A test apparatus for testing at least one switch device for a high-voltage battery of a vehicle, includes a voltage source for generating an electrical test voltage between a positive high-voltage path and a negative high-voltage path of the at least one switch device. The test apparatus has a first connecting device and a first current source for feeding a first electrical test current into the positive high-voltage path, wherein the first connecting device, the first current source and the positive high-voltage path together form a first circuit when testing the at least one switch device. The test apparatus has a second connecting device and a second current source for feeding a second electrical test current into the negative high-voltage path, wherein the second connecting device, the second current source and the negative high-voltage path together form a second circuit when testing the at least one switch device.

A method of determining if a circuit interrupter operating mechanism has an acceptable trip margin includes determining a model trip margin, providing a circuit interrupter, the circuit interrupter disposed in situ, the circuit interrupter including an operating mechanism, determining a circuit interrupter trip margin by: providing an internal sensor assembly, the internal trip margin sensor assembly structured to record trip margin data, providing a transfer function module, providing a computer structured to execute the transfer function module, executing the transfer function module on the computer, utilizing the trip margin sensor assembly to generate trip margin data, transmitting the trip margin data to the transfer function module, processing the trip margin data to generate a trip margin, and determining if the trip margin is acceptable relative to the model trip margin.

A method of determining if a circuit interrupter operating mechanism has an acceptable trip margin includes determining a model trip margin, providing a circuit interrupter, the circuit interrupter disposed in situ, the circuit interrupter including an operating mechanism, determining a circuit interrupter trip margin by: providing an internal sensor assembly, the internal trip margin sensor assembly structured to record trip margin data, providing a transfer function module, providing a computer structured to execute the transfer function module, executing the transfer function module on the computer, utilizing the trip margin sensor assembly to generate trip margin data, transmitting the trip margin data to the transfer function module, processing the trip margin data to generate a trip margin, and determining if the trip margin is acceptable relative to the model trip margin.