The invention relates to an overvoltage protection device with monitoring and communication functions, in particular for the information and process industries, having at least one surge arrester with a self-diagnostics unit and a wireless and/or wired standard interface for data transmission. According to the invention, an additional module is provided to detect the behaviour and/or the properties of a connected electrical energy source, wherein a bidirectional exchange of data and commands to and between a higher-level control system and among multiple overvoltage protection devices takes place and parametrisation of lower-level terminals to be protected can be realised via the standard interface.

An apparatus and method for monitoring the performance of a power line filter. The apparatus for monitoring the performance of a power line filter includes a performance degradation monitoring unit for monitoring performance degradation of individual components constituting a power line filter, and then generating performance degradation information, a frequency characteristic measurement unit for measuring frequency characteristics of the power line filter, and a performance monitoring unit for determining at least one of an operating state and performance of the power line filter based on the performance degradation information of the individual components and information on the frequency characteristics of the power line filter.

A sensor to monitor health of surge arresters such as metal oxide arresters is disclosed. The sensor includes a housing; a sensor assembly contained in the housing, the sensor assembly including an electronics board to receive, transmit, process, and store signals; and a voltage measurement strap extending around a periphery of the housing, the voltage measurement strap being electrically connected to the electronics board and configured to measure voltage using electric field.

A sensor to monitor health of surge arresters such as metal oxide arresters is disclosed. The sensor including a housing; a sensor assembly contained in the housing, and a voltage measurement strap extending around a periphery of the housing. The voltage measurement strap being electrically connected to the electronics board and configured to measure voltage using electric field. The sensor assembly including: an electronics board to receive, transmit, process, and store signals; a Rogowski coil electrically connected to the electronics board to measure surge currents diverted by the surge arrestor; and a current transformer electrically connected to the electronics board to measure leakage current.

A system or method for monitoring an electric power lightning arrester including an arrester current sensor providing an arrester current measurement, and an arrester voltage sensor providing an arrester voltage measurement. The system detects a switching signature based on the arrester current measurement or the arrester voltage measurement distinguished from background noise and lightning signatures and computes a measured arrester impedance based on the arrester current and arrester voltage measurements. The system then compares the measured arrester impedance to a nominal or historical arrester impedance, determines that the arrester is faltering based on the comparison of the measured arrester impedance to the nominal or historical arrester impedance, and places an order for replacement of the arrester based on the determination that the arrester is faltering. The system operator then replaces the arrester during a fair-weather, typically off-peak period to avoid failure of the arrester during a lightning strike.

Example implementations relate to circuits. For example, an implementation includes a detection circuit including a comparator circuit. The comparator circuit includes a first input terminal, a second input terminal, and an output terminal. The detection circuit also includes a reference voltage circuit to provide a set point voltage to the comparator circuit via the first input terminal. The detection circuit further includes a diode to reduce the set point voltage from a first magnitude to a second magnitude when the first magnitude is equal to or lower than a magnitude of the load voltage.

The object of the invention is an overvoltage protection apparatus with monitoring function having a parallel circuit of two branch circuits, wherein the first branch circuit has a first overvoltage protection device and a second overvoltage protection device that are connected in series, wherein the second branch circuit has a third device and a fourth device that are connected in series, wherein the first overvoltage device and the third device have a first shared voltage potential during operation, and wherein the second overvoltage device and the fourth device have a second shared voltage potential during operation, wherein a first measuring tap is provided between the first overvoltage protection device and the second overvoltage protection device and wherein a second measuring tap is provided between the third device and the fourth device, with a signal being derived from the voltage between the first measuring tap and the second measuring tap that provides state information in relation to the first overvoltage protection device and the second overvoltage protection device.

An insulation resistance measuring device including a positive electrode test resistor connected to a positive electrode node of a battery assembly, a negative electrode test resistor connected to a negative electrode node of the battery assembly, a first switch connecting the positive electrode node of the battery assembly to the positive electrode test resistor, a second switch connecting the negative electrode node of the battery assembly to the negative electrode test resistor, a voltage measurement unit that measures a first voltage applied to the positive electrode test resistor and a second voltage applied to the negative electrode test resistor, and a voltage estimation unit that estimates a final convergence value of the first and second voltages.

An instrumented electric power arrester includes a temperature sensor, wireless transmitter, and a visual over-temperature indicator. A disk shaped module, a replacement varister block, or a dummy block containing the sensor/transmitter is placed between varister blocks inside the arrester housing. A strap-on module is attached to the outside of the arrester housing. The sensor/transmitter utilizes a harvesting power supply that draws electric power for the electronics from the power line protected by the arrester. An ambient temperature sensor may be utilized to enhance accuracy. The temperature sensor/transmitter typically sends arrester monitoring data wirelessly to an RTU or handheld unit located outside the arrester, which relays the monitoring data to an operations control center that scheduled replacement of the arrester based on the monitoring data. A surge counter keeps track of the number of equipment and lightening related temperature surges experienced by the arrester.

A semiconductor integrated circuit of the present disclosure includes: first power and second power supply lines that are coupled to a protected circuit; a third power supply line that is supplied with a voltage different from voltages supplied to the first and second power supply lines; a detection circuit that is coupled between the first and second power supply lines and detects a surge occurring in the first power supply line; an inverter circuit that includes one or more inverters coupled in series, and is coupled between the first and second power supply lines; a protection transistor that is coupled between the first and second power supply lines, and is controlled by an output of the detection circuit to cause the surge to flow through the second power supply line; and a time constant circuit that is coupled to at least the third power supply line and the protection transistor.