Arc fault detection modules for vehicles intended to supervise circuits and detect arc fault conditions in both alternating current and direct current circuits. A number of these arc fault detection modules may be integrated into a vehicle's electrical system in strategic locations. Each arc fault module contains sensing capabilities for monitoring the circuit, and may also include signal conditioning capabilities, processing capabilities for determining the occurrence of an arc fault, contactors for disabling the supervised circuit, and communications capabilities to interact with other vehicle components and telematics systems. As a result arc fault detection odules can be customized to leverage existing features of a vehicle's electrical system or to provide fully redundant arc fault protection.

A method and a photovoltaic inverter for determining the insulation resistance of a photovoltaic system relative to ground are provided. The voltage required for the measurement can be provided by an intermediate circuit in the form of an intermediate circuit voltage and a measuring device is designed to actuate an input short-circuit switch for short-circuiting a DC input with an AC disconnector open, as a result of which the intermediate circuit voltage can be applied to the DC input in the reverse direction. The measuring device is configured to record measured voltages with a switch of a voltage divider open and closed, and to determine the insulation resistance from the measured values of the two measured voltages recorded with the switch of the voltage divider open and closed.

An instrumented electric power voltage 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 lightning related temperature surges experienced by the arrester.

A system and method for use in environment with electrical equipment is provided. The system including a housing and at least one light source located on an exterior of the housing. The light source being activated when the system is in a switching mode of operation. At least one sensor is operably coupled to the housing and configured to measure at least one parameter associated with the electrical equipment. A computing device is disposed within the housing and coupled to communicate with the at least one light source and the at least one sensor.

A system and method for use in environment with electrical equipment is provided. The system including a housing and at least one light source located on an exterior of the housing. The light source being activated when the system is in a switching mode of operation. At least one sensor is operably coupled to the housing and configured to measure at least one parameter associated with the electrical equipment. A computing device is disposed within the housing and coupled to communicate with the at least one light source and the at least one sensor.

A method of determining polymerisation of transformer insulation within a transformer. The method includes the steps of measuring a first and second moisture activity of oil in a transformer, and a first and second temperature of the transformer. The method further includes calculating the ratio of the gradients of the moisture equilibrium curves associated with the moisture activity and the temperature. The calculated ratio can then be used to characterise the polymerisation of the insulation and age of the transformer.

A protection device configured for being electrically connected to a test tap of a HV bushing for protecting the bushing from transient overvoltages. The protection device includes at least two parallel connected protection branches connected between the test tap and a ground connector configured for connecting to ground. Each of the protection branches includes a plurality of parallel connected gas discharge tubes, a Transient-Voltage-Suppression (TVS) diode connected in series with the gas discharge tubes, and a resistor connected in series with the gas discharge tubes and across the TVS diode.

An approach to detecting partial discharge events involves retrofitting an electrical system to include a capacitive sensor configured to capacitively sense partial discharge events of a component of the electrical system. The capacitive sensor has a first electrical conductor that forms a first terminal of the capacitive sensor, a second electrical conductor that forms a second terminal of the capacitive sensor, and a dielectric that separates the first electrical conductor and the second electrical conductor. The capacitive sensor generates an electrical sensor signal at an output of the capacitive sensor in response to the partial discharge event. The electrical sensor signal is converted to an optical signal and the optical signal is processed to detect an occurrence of the partial discharge event.

The invention relates to an electric circuit arrangement (20) for the functional testing of a monitoring device (4) for a power supply system (2), the electric circuit arrangement (20) having a test resistance (R.sub.f1, R.sub.f2) which is switched between an active conductor (L.sub.1, L.sub.2) of the power supply system (2) and ground (PE) and has a settable actual resistance value (R.sub.x). In this context, a bidirectional cascade (12) consisting of field-effect transistors as test resistances (R.sub.f1, R.sub.f2) and an analog control (10) for the continuous-value setting of the actual resistance value (R.sub.x) to a predefined target resistance value (R.sub.0) are provided. Furthermore, the invention relates to a modular circuit arrangement (60) consisting of several electric circuit arrangements (20) according to the invention, each of the electric circuit arrangements (20) being assigned a different active conductor (L.sub.1, L.sub.2) of the electric power supply system (2), and a central control unit (50) being implemented for controlling and monitoring the electric circuit arrangements (20).

A test device to localize a partial discharge in or at an electrical component may include at least one antenna to capture an electromagnetic wave caused by a partial discharge in the electrical component. The test device includes multiple microphones arranged in an environment around the electrical component. The microphones capture sound waves caused by the partial discharge. It is examined if an intensity of the electromagnetic wave exceeds a first limit value and/or the intensity of the sound wave captured by one of the multiple microphones exceeds a second limit value. Depending on the captured sound wave and/or the electromagnetic wave and on the examination relating to the first and/or second limit value, a location of the partial discharge can be determined.