Abstract: A transformer assembly includes an electric transformer, a temperature sensor system, and a computation unit for determining a thermal state of the electric transformer. The electric transformer includes a cooling device having at least one liquid coolant channel to absorb exhaust heat from the electric transformer, a heat spreader for transferring heat from the liquid coolant to a heat dissipation surface of the heat spreader, and an air blower configured to effect an airstream along the heat dissipation surface. The temperature sensor system includes an entering coolant sensor for providing an entering coolant temperature signal, a leaving coolant sensor for providing a leaving coolant temperature signal, an entering airstream sensor providing an entering airstream temperature signal, and a leaving airstream sensor providing a leaving airstream temperature signal. The computation unit is configured to determine a thermal state of the transformer.

Abstract: A transformer includes a tank with an insulating fluid, a radiator for cooling the insulating fluid, and one or more sensors arranged to measure insulating fluid properties in a location where the insulating fluid has a lower temperature.

Abstract: A method for monitoring an amount of a chemical material that includes: providing an at least one portable container; and providing into the at least one portable container a first amount of the chemical material. The method includes operatively associating a sensor with the at least one portable container, the sensor effective to detect a first level of the chemical material in the at least portable container and to generate a first data signal based on the first level. The method includes operating the sensor to detect a change in the amount of the chemical material in the at least one portable container, and thereby to generate a second data signal based on the change. The method includes using a processor in operable communication with the sensor.

Abstract: A power distribution management apparatus includes an electrical connection storage unit, a search unit, and an output unit. The electrical connection storage unit is configured to store electrical connection information in which a combination of a plurality of junctions that describes which a plurality of facilities of a power distribution system are electrically connected to each other and a facility determined based on the combination are associated. The search unit is configured to search a facility corresponding to the combination while investigating an uninvestigated junction among the plurality of junctions contained in the combination starting from a predetermined junction with reference to the electrical connection information stored in the electrical connection storage unit. The output unit is configured to output facility information obtained from the combination where the investigation is performed and a result of the search after the investigation and the search are performed.

Abstract: A diagnostic device includes an input unit that accepts input of an onomatopoeia to use in a sound sample search, a search unit that searches for a sound sample matching the input onomatopoeia, and a display that displays a search result from the search unit.

Abstract: A system, a method and a computer program to monitor a plurality of transformer operating parameters, as well as to accurately control one or more of the transformer operating parameters. Also, the system and method may calculate loss of life and give diagnosis for recovery and provide maintenance notification, along with monitoring the operation of the LTC.

Abstract: A remotely readable apparatus for metering of a plurality of electricity consumer lines, comprising: (a) a meter head that measures electricity usage for each of the plurality of electricity consumer lines; and (b) sensors that sense environmental conditions in a second housing enclosing a distribution transformer that steps down voltage from a distribution level to a consumer level, said one sensors in communication with said meter head and not operable to sense environmental conditions in said first housing, and wherein said meter head connects and disconnects service on said plurality of electricity consumer lines in response to information received from said sensors; wherein a transponder transmits data received to/from said meter head to/from a remotely located computer, and said meter head is operable, based on data received from said transponder, to connect/disconnect service on said electricity consumer lines.

Abstract: A system to identify potential faults in an electrical power distribution system includes a vibration monitor configured to detect a vibration event proximate a portion of the electrical power distribution system, a power quality monitor configured to detect a power quality event in a portion of the electrical power distribution system, an analysis system configured to correlate the vibration event detected by the vibration monitor with the power quality event detected by the power quality monitor, and an output configured to receive information regarding the power quality event from the analysis system and to provide the information to an operator.

Abstract: The present disclosure is a system for monitoring power that has a unified polyphase distribution transformer monitoring (PDTM) device that interfaces with at least three electrical conductors electrically connected to a transformer. In addition, the PDTM device measures a current and a voltage of each of the three electrical conductors. Additionally, the system has logic that calculates values indicative of power corresponding to the transformer based upon the currents and the voltages measured and transmit data indicative of the calculated values.

Abstract: Various methods and systems are directed to a mislinked meter system that identifies utility meters mislinked to a distribution transformer in a data store. Utility meters reporting voltages that vary more than other meters linked to the same distribution transformer in the data store may be physically linked to a different distribution transformer. To compare meter voltages, the mislinked meter system generates normal meter errors for the utility meters and a normal transformer error for some or all of the utility meters linked to the same distribution transformer. The normal meter error and transformer error represent the amount the voltages of a utility meter varies from the voltages of the other utility meters associated with the distribution transformer. The more the meter errors vary when compared to the transformer error, the more likely a utility meter is mislinked to the wrong distribution transformer in the data store.

Abstract: An illustrative method of evaluating a condition of a plurality of transformers that are located remotely from each other, includes: obtaining an ambient temperature for respective sites of the transformers at a plurality of times during a period; determining respective loading at the transformers at the plurality of times; and determining respective aging rates of the transformers during the period based on the respective ambient temperatures and loadings.

Abstract: This invention publishes a fault diagnosis and location system for transformer core looseness, consists of vibration sensors, data collection and computer. It is of power transformer fault intelligent diagnosis technology technical field. Fault diagnosis and location method uses three vibration sensors positioned on the top of transformer tank, to obtain vibration signal, uses signal processing to analyze the signal, and obtains fault characteristics of the transformer core looseness. The characteristics respectively are 50 Hz, 150 Hz and 300 Hz frequency components, in which 300 Hz is main feature. When they reach a certain value at one position, it suggests that transformer core looseness near this position. By the comparison of differences among signals of three positions, fault location can be done. This invention manifests fault characteristics accurately and detects core looseness efficiently.

Abstract: The present invention is a unique system for liquid-immersed transformers and reactors with complex internal thermal gradients that provides telemetry on multiple transformer or reactor conditions including: the level and volume of the liquid, the integrity of the winding clamping, the overall tank pressure, the gas pressure for gas blanketed transformers, and the condition of the breather for conservator type transformers or reactors, and the impacts from ballistics on the tank or cooling system. The present invention can be used on conservator type or gas blanketed type transformers. The liquid level can be calculated at any level in the transformer or reactor by the location of the oil pressure sensor at the bottom of the tank. The method for calculating liquid level does not require liquid temperature measurement. Average liquid temperature is calculated rather than estimated from discrete measurements, providing accurate average temperature values under all operating conditions.

Abstract: An airbag ECU includes a voltage detection section that detects a voltage in a power supply supplied to other control units (for example, front passenger seat occupancy sensing ECU). In addition, the airbag ECU includes a timer that measures an elapsed time after the voltage detected by the voltage detection section falls in a preset voltage range and a recording section that records the elapsed time measured by the timer on a memory when a failure of the other control units is detected.

Abstract: A system and method for real-time feeder reconfiguration are disclosed for load balancing in distribution system automation. The load balancing of transformers and feeders can be achieved by load transfer from an overloaded transformer or feeder to an adjacent transformer or feeder which is lightly loaded. An exemplary method can include defining an objective function as a sum of squares of the load deviation of transformers/feeders. The minimization of this objective function determines the optimal operating states (open or closed) of sectionalizing switches. The load balancing operation of transformer and feeder can be carried out by a single operation in which a plurality of switches is reconfigured.

Abstract: A protective system far a power transformer having a neutral line connected to ground where large currents can flow in the neutral line due to electro-magnetic disturbances. The system includes circuitry for: (a) sensing the current level in the neutral line and whether it exceeds a predetermined threshold for a predetermined period; and (b) sensing and processing the harmonic content of the load current and determining the existence of certain relationships of the “even” and “odd” harmonics. Signals, including alarms, indicative of excessive conditions are produced. The system may also include circuitry for sensing the load current level and generating a signal alarm if the load level is above a given value when the harmonics and the DC current have values in excess of certain predetermined values.

Abstract: The present invention provides a system and computer program product for implementing a smart transformer, comprising a processor, and a balancing algorithm residing on the processor, wherein the balancing algorithm is stored on a non-transitory computer readable medium having computer executable program code embodied thereon, the computer executable program code configured to cause the system to monitor and control an electric customer load and generation in order to optimize the performance of a distribution transformer, wherein the processor receives a plurality of system inputs and uses the balancing algorithm to determine a rating of the transformer and an amount of customer load.

Abstract: A method for determining the health of a transformer through vibration measurement is disclosed. A vibratory signal, in the form of a physical mechanical vibration or auditory signal, is received at a sensor. The vibratory signal is converted into a frequency representation of the signal to derive its harmonics. Based on the power level for the harmonics in the vibratory signal, the harmonic current ratios in the transformer are calculated. The harmonic current ratios are summed together to quantify the health of the transformer. This value is called a K-factor, and is a quantification of the health of the transformer.

Abstract: The present invention relates to a device for current measuring in power supply networks comprising transformers for measuring current, a signal processing apparatus arranged on a printed circuit board and screw fastenings for mounting the device. The cable ducts of the transformers are orientated parallel to the plane of the printed circuit board, which has openings flush to the cable ducts, and the screw fastenings are fastening tabs with mounting holes, spaced so standards-compliant mounting is possible. In an alternate embodiment, the cable ducts are orientated perpendicularly to the plane of the printed circuit board, the screw fastenings are constructed as an angle rail with cable outlets and standards-compliant mounting holes, and the printed circuit board is internally fastened on one side of the angle rail. In another alternate embodiment the transformers are installed with the printed circuit board in a common housing with fastening tabs and standards-compliant mounting holes.

Abstract: A method for measuring the real hot-spot temperature in an electric apparatus containing an oil, such as an electric power transformer. The electric apparatus is operated under predetermined and modifiable operating conditions. This method comprises the use of one or several chemical compounds or tracers present and soluble in the oil. Each tracer may transform, at a given temperature, in order to form a residue, such as a soluble gas. From the presence of the residue in the oil, the operator will be able to determine under which predetermined operating condition the hot-spot has been reached and to deduce the hot-spot for a given condition. Among different used compounds, there are diazoic compounds, carbonyl metals, colorants, pigments, liquid crystals and albumins. The method also allows to check the quality of the apparatus on the market and to estimate its life span.

Abstract: A residual-current circuit breaker includes at least one summation current transformer through which a first lead and a second lead of a network to be protected are guided. At least one secondary winding is arranged on the summation current transformer and operatively connected, at least indirectly, with an energy storage element. A trip element is operatively connected with break contacts in the first and second leads. In order to reduce expected cut-offs of a network to be protected, an electric signaling device is operatively connected, at least indirectly, with the energy storage element.

Abstract: An energy monitoring system for a power conductor includes a base unit; a sensor cable; and a current transformer electrically connected to the base unit by the sensor cable. The current transformer includes a secondary winding inductively coupled to the power conductor and a clamping circuit electrically connected in parallel with the secondary winding. The clamping circuit is structured to clamp a voltage across the secondary winding when the voltage across the secondary winding is greater than a predetermined value. An indicator circuit is electrically connected in series with the clamping circuit to indicate when the clamping circuit is actively clamping the voltage.

Abstract: An energy monitoring system for a power conductor includes a base unit; a sensor cable; and a current transformer electrically connected to the base unit by the sensor cable. The current transformer includes a secondary winding inductively coupled to the power conductor and a clamping circuit electrically connected in parallel with the secondary winding. The clamping circuit is structured to clamp a voltage across the secondary winding when the voltage across the secondary winding is greater than a predetermined value. An indicator circuit is electrically connected in series with the clamping circuit to indicate when the clamping circuit is actively clamping the voltage.

Abstract: An apparatus (100) adapted to measure Alternating Current flowing through an electricity supply distribution unit (204) having a plurality of distribution cables (202). The apparatus (100) includes a plurality of current measuring devices (102), each of the current measuring devices (102), in use, measuring current flowing through one of the distribution cables (202), at least some of the current measuring devices (102) being mounted on a rigid/semi-rigid body (104), and a device configured to store and/or transfer information representing current measured by at least one of the current measuring devices (102).

Abstract: A PeakPower Energy Management and Control System having one or more roll-lock snap-on current transformer power monitoring devices, each to avoid interrupting power when installing current and/or power monitors. Each roll-lock snap-on current transformer power monitoring device may be snapped onto existing power wires inside a power panel or near equipment being monitored without disconnecting any wires or turning off power. Each roll-lock snap-on current transformer power monitoring device may be utilized in standalone mode as well as within a PeakPower Energy Management and Control System in accordance with disclosed embodiments. Each roll-lock snap-on current transformer power monitoring device may communicate via the power lines (Power Line Controller) or communicate via wireless using an integrated microprocessor based RF transceiver.

Abstract: Systems and methods for generating a collector flashover alert by passive monitoring of a generator are provided. One method includes receiving, by a computing device, signals from a current transformer coupled around an exciter cable connected to a generator collector assembly, determining, by the computing device, when a spark has occurred in the generator collector assembly based at least in part on received signals from the current transformer, generating an indication that a spark has occurred in the generator collector assembly when it is determined that a spark has occurred in the generator collector assembly, and generating a flashover alert based at least in part on the generated indication that a spark has occurred in the generator collector assembly.

Abstract: A battery monitoring system utilizes a plurality of transformers interconnected with a battery having a plurality of battery cells. Windings of the transformers are driven with an excitation waveform whereupon signals are responsively detected, which indicate a health of the battery. In one embodiment, excitation windings and sense windings are separately provided for the plurality of transformers such that the excitation waveform is applied to the excitation windings and the signals are detected on the sense windings. In one embodiment, the number of sense windings and/or excitation windings is varied to permit location of underperforming battery cells utilizing a peak voltage detector.

Abstract: A power and signal distribution system comprises a converter unit connected to a plurality of control units. The converter unit and the control units are arranged in areas difficult to access, for instance on the sea bed. The converter unit is connected to a remote monitoring and supplying device via at least one cable connection. Each control unit has assigned thereto at least one production apparatus for crude oil or natural gas corresponding gate valves, chokes, biops, actuators. In some embodiments, the power and signal distribution system the converter unit comprises a data separation device and a voltage converter. The converted voltage from the voltage converter is transmitted together with data/signals from the converter unit to at least one of the control units.

Abstract: System for monitoring oil level and detecting leaks in power transformers, reactors, current and potential transformers, high voltage bushings and the like, notably for a system that through the use of sensors and other electronic components measures and monitors transformers and similar equipment in real time, filled with insulating oil, with greater precision and without need for floats or mobile mechanical parts, while presenting countless facilities in the sense of making level monitoring more reliable and safer, highlighting the level error calculations, oil leak detection alarm, excess oil detection alarm during the equipment filling process and calculation of tendencies of evolution for levels among other facilities.

Abstract: A residual-current circuit breaker includes at least one summation current transformer through which at least one first lead and one second lead of a network to be protected are guided. At least one secondary winding is arranged on the summation current transformer and operatively connected at least indirectly with at least one energy storage element. At least one discharging resistor is switched in parallel with the energy storage element. The residual-current circuit breaker has a trip element which is operatively connected with break contacts in the at least one first lead and the at least one second lead. In order to reduce unexpected cut-offs of a network to be protected, the at least one discharging resistor includes a first partial resistor, and a second partial resistor switched in series with respect to the first partial resistor, with a least one electric signaling device operatively connected, at least indirectly, with the first partial resistor.

Abstract: The present invention relates to a device for current measuring in power supply networks comprising transformers for measuring current, a signal processing apparatus arranged on a printed circuit board and screw fastenings for mounting the device. The cable ducts of the transformers are orientated parallel to the plane of the printed circuit board, which has openings flush to the cable ducts, and the screw fastenings are fastening tabs with mounting holes, spaced so standards-compliant mounting is possible. In an alternate embodiment, the cable ducts are orientated perpendicularly to the plane of the printed circuit board, the screw fastenings are constructed as an angle rail with cable outlets and standards-compliant mounting holes, and the printed circuit board is internally fastened on one side of the angle rail. In another alternate embodiment the transformers are installed with the printed circuit board in a common housing with fastening tabs and standards-compliant mounting holes.

Abstract: A power and signal distribution system comprises a converter unit connected to a plurality of control units. The converter unit and the control units are arranged in areas difficult to access, for instance on the sea bed. The converter unit is connected to a remote monitoring and supplying device via at least one cable connection. Each control unit has assigned thereto at least one production apparatus for crude oil or natural gas corresponding gate valves, chokes, biops, actuators. In some embodiments, the power and signal distribution system the converter unit comprises a data separation device and a voltage converter. The converted voltage from the voltage converter is transmitted together with data/signals from the converter unit to at least one of the control units.

Abstract: A system for cooling a power transformer which generates heat, when driving a load, includes cooling devices, such as fans and pumps, located about the transformer, which are powered for circulating a coolant about the transformer. Each cooling device has a motor which is energized in response to given temperature (heat) conditions. In systems embodying the invention, the currents flowing through the motors of cooling devices are sensed and monitored to determine whether the cooling devices are functioning correctly and to substitute functional cooling devices for those which are malfunctioning. Sensing the currents in the motors enables the early detection of fault conditions in the cooling system. It also enables the monitoring of operating conditions and running time of the cooling devices to aid in the maintenance and operation of the cooling system.

Abstract: A PeakPower Energy Management and Control System having one or more roll-lock snap-on current transformer power monitoring devices, each to avoid interrupting power when installing current and/or power monitors. Each roll-lock snap-on current transformer power monitoring device may be snapped onto existing power wires inside a power panel or near equipment being monitored without disconnecting any wires or turning off power. Each roll-lock snap-on current transformer power monitoring device may be utilized in standalone mode as well as within a PeakPower Energy Management and Control System in accordance with disclosed embodiments. Each roll-lock snap-on current transformer power monitoring device may communicate via the power lines (Power Line Controller) or communicate via wireless using an integrated microprocessor based RF transceiver.

Abstract: The present invention provides a system and computer program product for implementing a smart transformer, comprising a processor, and a balancing algorithm residing on the processor, wherein the balancing algorithm is stored on a non-transitory computer readable medium having computer executable program code embodied thereon, the computer executable program code configured to cause the system to monitor and control an electric customer load and generation in order to optimize the performance of a distribution transform wherein the processor receives a plurality of system inputs and uses the balancing algorithm to determine a rating of the transformer and an amount of customer load.

Abstract: A system, device, and method of detecting an overload condition of a distribution transformer that supplies power to one or more customer premises via a low voltage subnet is provided. In one embodiment, the method comprises determining the power output of the transformer; storing in a memory a threshold power value for the transformer; determining whether the power output exceeds the threshold power value; and, if the output power exceeds the threshold power value, providing a notification. Providing the notification may include wirelessly transmitting the notification and/or transmitting the notification over a medium voltage power line. The low voltage subnet may comprise a low voltage feeder that supplies power to a plurality of low voltage supply lines that extend to the customer premises in which case determining the output power may comprise measuring a voltage of the low voltage feeder and measuring a current traversing the low voltage feeder.

Abstract: A device and method for monitoring the condition of an electrical power transformer in an electrical power grid synchronously measures current and voltage data at both a high voltage side of the transformer and a low-voltage side of the transformer and computes from this measured data corresponding transformer impedance data. These measurements and computations are repeated continuously in real time at a rates up to 30 Hz to provide a sequence of real-time transformer impedance data. An alarm signal is generated if a mean of the sequence of real-time transformer impedance data changes significantly.

Abstract: System and method for detecting partial discharge arcing phenomena in a power network distribution system which employs a mobile receiving assemblage including a wideband antenna, a computer controllable wideband radio receiver deriving an amplitude detected output and a global positioning system providing system position data. The amplitude detected outputs are digitized and treated with a digital signal processor based analysis including fast Fourier transforms extracting narrowband signal frequencies that are harmonically related to the network fundamental frequency. The narrowband signal frequencies are analyzed for peak amplitudes which are summed to derive maintenance merit values related to the arcing phenomena.

Abstract: An Intelligent Electronic Device with integrated protection, and/or control, and/or monitoring for two power system primary objects or more power system primary objects, responsive to a plurality of inputs from the power system primary objects, and providing a plurality of outputs to the power system primary objects.

Abstract: A system, device, and method of detecting an overload condition of a distribution transformer that supplies power to one or more customer premises via a low voltage subnet is provided. In one embodiment, the method comprises determining the power output of the transformer; storing in a memory a threshold power value for the transformer; determining whether the power output exceeds the threshold power value; and, if the output power exceeds the threshold power value, providing a notification. Providing the notification may include wirelessly transmitting the notification and/or transmitting the notification over a medium voltage power line. The low voltage subnet may comprise a low voltage feeder that supplies power to a plurality of low voltage supply lines that extend to the customer premises in which case determining the output power may comprise measuring a voltage of the low voltage feeder and measuring a current traversing the low voltage feeder.

Abstract: It is intended to provide a tap change operation monitoring apparatus for an on-load tap changer which can employ relatively simple and low-cost torque sensing means by mitigating an accuracy requirement with regard to detecting a starting time of tap change operation, acquire torque waveform data concerning tap change operation of a diverter switch in an accurate and reliable fashion, and discriminate an abnormal state of the tap change operation with high accuracy.

Abstract: The present invention provides a system and method for monitoring vibration of a power transformer. The system comprises at least one vibration sensor operably mounted to the outer case of a transformer for sensing vibration of the power transformer; a spectrum analyzer for processing the vibration signal from the vibration sensor, the spectrum analyzer generating a frequency spectrum of the vibration signal and calculating a velocity rating from the frequency spectrum; a diagnosing means for evaluating the velocity rating of the vibration signal, the diagnosing means assigning a vibration grade for each velocity rating, the diagnosing means finding the maximum velocity rating; and a means for dispatching a control message to an operator when the maximum velocity rating reaches a threshold value. It can be appreciated that the mechanical health of a large-sized transformer can be managed in a systematic and efficient manner during its operation.

Abstract: A system, device, and method of detecting an overload condition of a distribution transformer that supplies power to one or more customer premises via a low voltage subnet is provided. In one embodiment, the method comprises determining the power output of the transformer; storing in a memory a threshold power value for the transformer; determining whether the power output exceeds the threshold power value; and, if the output power exceeds the threshold power value, providing a notification. Providing the notification may include wirelessly transmitting the notification and/or transmitting the notification over a medium voltage power line. The low voltage subnet may comprise a low voltage feeder that supplies power to a plurality of low voltage supply lines that extend to the customer premises in which case determining the output power may comprise measuring a voltage of the low voltage feeder and measuring a current traversing the low voltage feeder.

Abstract: A system, device and method of determining an efficiency of a distribution transformer that receives power from a medium voltage power line and that provides power to a plurality of customer premises via a low voltage subnet is provided. In one embodiment, the method includes determining an input power to the transformer from the medium voltage power line, determining an output power from the transformer, determining a transformer efficiency based on the input power and the output power, comparing the transformer efficiency with a threshold efficiency, and providing a notification when the transformer efficiency is below a threshold efficiency. Determining the input power may include measuring the current input and estimating the voltage input based on a voltage measure of the low voltage subnet and the turns ratio of the transformer.

Abstract: System and method for detecting partial discharge arcing phenomena in a power network distribution system which employs a mobile receiving assemblage including a wideband antenna, a computer controllable wideband radio receiver deriving an amplitude detected output and a global positioning system providing system position data. The amplitude detected outputs are digitized and treated with a digital signal processor based analysis including fast Fourier transforms extracting narrowband signal frequencies that are harmonically related to the network fundamental frequency. The narrowband signal frequencies are analyzed for peak amplitudes which are summed to derive maintenance merit values related to the arcing phenomena.

Abstract: A system (30) includes an analysis engine (34) and a notification engine (38) for selective notification of a condition (72) of an apparatus (26) monitored by a monitoring device (28). A method executed by the system (30) receives (116) data elements (58) from the monitoring device (28), processes (118) the data elements (58) to detect the condition (72) of the apparatus (26), and determines that the condition (72) defines an exception (74) to a normal condition (70) of the apparatus (26). A first notice (60) of the condition (72) is conveyed (146) to a responsible party (59) at a first instance of determination of the exception (74), and conveyance of a second notice (60) is prevented (140) at a second, subsequent, instance of determination of the exception (74). In addition, communication of the normal condition (70) of the apparatus (26) is prevented.

Abstract: A stationary induction apparatus has: a winding to which AC current is supplied; an electrostatic shield which includes an electrostatic shield member having a hollow and an electrically conductive film wound around the electrostatic shield member, and which is configured to suppress the electric field of the winding; a housing which contains the winding, the electrostatic shield and the insulating fluid; an IC tag which has a sensor arranged in the hollow of the electrostatic shield member and configured to detect position of the electrostatic shield member, and a transmitter unit configured to transmit, by radio, information acquired by the sensor as a high-frequency signal having a frequency much higher than the frequency of the AC current; and a receiver unit which is arranged in the housing, receives the high-frequency signal transmitted by radio from the IC tag and transmits, by wire, the signal outside the housing.

Abstract: A system, device, and method of detecting an overload condition of a distribution transformer that supplies power to one or more customer premises via a low voltage subnet is provided. In one embodiment, the method comprises determining the power output of the transformer; storing in a memory a threshold power value for the transformer; determining whether the power output exceeds the threshold power value; and, if the output power exceeds the threshold power value, providing a notification. Providing the notification may include wirelessly transmitting the notification and/or transmitting the notification over a medium voltage power line. The low voltage subnet may comprise a low voltage feeder that supplies power to a plurality of low voltage supply lines that extend to the customer premises in which case determining the output power may comprise measuring a voltage of the low voltage feeder and measuring a current traversing the low voltage feeder.

Abstract: A power equipment includes a first internal abnormality detection apparatus comprising a first antenna accommodation pipe which is connected to a first connection pipe formed in a enclosed container and which accommodates a first antenna therein, and a first signal detection circuit which is connected to a first antenna and which detects an electromagnetic wave signal emitted when any abnormality has occurred within the enclosed container.

Abstract: A device for monitoring a leakage current of a surge arrester has a measuring element for detecting a leakage current in a leakage current circuit. A filter assembly filters the leakage current in order to extract a third harmonic oscillation which is evaluated by an evaluation circuit with respect to the value thereof. The evaluation circuit delivers at least one warning signal to a display device. In a preferred embodiment, three display devices operating as a signaling light are provided. A power supply for the used circuits is obtainable by way of a transformer which extracts a necessary auxiliary zero-potential energy contained in the leakage current and with the aid of a main power supply unit connected to the transformer.