Abstract: A system analyzes a state of an inductive operator. The system includes a measuring device that is configured to: detect an acoustic reference signal and a plurality of operating variables, which can change over time, of the inductive operator or a reference inductive operator during a reference time period; and detect an acoustic signal and the operating variables during a productive time period. The system also includes an evaluating device that is configured to: generate a reference data set from the reference signal and a productive data set from the acoustic signal; perform a regression analysis of the reference data set and thereby create a model for description of the acoustic reference signal by the operating variables; and generate a state evaluation of the inductive operator from a difference between the productive data set and values modelled in accordance with the model.

Abstract: The invention relates to a method and to a system (1) for monitoring at least one inductive operating means (TR). The inductive operating means (TR) is used in a power supply network. For this purpose, each inductive operating means is assigned a monitoring unit (2). Real-time data (22) relating to the current state of the inductive operating means (TR) can be stored in a data store (4) of the monitoring unit (2). An evaluation unit (6) of the monitoring unit (2) is communicatively connected to the data store (4). By means of the monitoring unit (2), a failure rate (FR) for the at least one inductive operating means (TR) is determined according to a state factor (CF).

Abstract: A system analyzes a state of an inductive operator. The system includes a measuring device that is configured to: detect an acoustic reference signal and a plurality of operating variables, which can change over time, of the inductive operator or a reference inductive operator during a reference time period; and detect an acoustic signal and the operating variables during a productive time period. The system also includes an evaluating device that is configured to: generate a reference data set from the reference signal and a productive data set from the acoustic signal; perform a regression analysis of the reference data set and thereby create a model for description of the acoustic reference signal by the operating variables; and generate a state evaluation of the inductive operator from a difference between the productive data set and values modelled in accordance with the model.

Abstract: A method monitors capacitor bushings for an AC mains. The mains has first-third phases, associated with first-third mains lines, capacitor bushings, and mains voltages. Each capacitor bushing has a conductor, surrounded by foil, connecting its mains line. The method includes: at a first instant, for each phase: a first reference voltage phasor is determined; and a foil voltage present between the respective foil and ground potential is detected and a corresponding first foil voltage phasor is determined; at a second instant, for each of the phases: a second reference voltage phasor is determined; the foil voltage is detected and a second foil voltage phasor is determined; for each capacitor bushing: a loss factor change is calculated based on the respective reference voltages and foil phasors and those of the adjacent capacitive bushing; and a monitoring signal is generated based on a comparison of the loss factor and a tolerance value.

Abstract: A method monitors capacitor bushings of a three-phase AC mains, which has first, second, and third mains lines respectively associated with first, second, and third: phases, capacitor bushings, and mains voltages. Each of the capacitor bushings has: a conductor connected with the associated mains line, and an electrically conductive foil enclosing the conductor. The method includes, for each of the phases: determining, at a predetermined initial instant for a characteristic variable, which is characteristic for the respective capacitor bushing, a corresponding characteristic value; determining, at a predetermined later instant after the initial instant for the characteristic variable, a corresponding normalised characteristic value in dependence on the respective characteristic value and/or on at least one of remaining characteristic values; and checking whether the normalised characteristic value has impermissibly changed.

Abstract: A method monitors capacitor bushings of a three-phase AC mains, which has first, second, and third mains lines respectively associated with first, second, and third: phases, capacitor bushings, and mains voltages. Each of the capacitor bushings has: a conductor connected with the associated mains line, and an electrically conductive foil enclosing the conductor. The method includes, for each of the phases: determining, at a predetermined initial instant for a characteristic variable, which is characteristic for the respective capacitor bushing, a corresponding characteristic value; determining, at a predetermined later instant after the initial instant for the characteristic variable, a corresponding normalised characteristic value in dependence on the respective characteristic value and/or on at least one of remaining characteristic values; and checking whether the normalised characteristic value has impermissibly changed.

Abstract: A system detects physical variables of at least one component of a tapped transformer and monitors the at least one component of the tapped transformer. The system includes a computer in communicating with a measuring instrument, which is in communicating connection with a sensor for reception of the physical variables. The computer receives the physical variables, which are collected in the measuring instrument, as a function of time of the at least one sensor; filters the physical variables as a function of time to generate filtered signals, and creates from the filtered signals a highly resolved envelope representing a signal level of the physical variables; and determines a first limit value curve and a second limit value curve, the position of which is variable in a direction of an ordinate, and the first limit value curve represents the limit value.

Abstract: A method monitors capacitor bushings for an AC mains. The mains has first-third phases, associated with first-third mains lines, capacitor bushings, and mains voltages. Each capacitor bushing has a conductor, surrounded by foil, connecting its mains line. The method includes: at a first instant, for each phase: a first reference voltage phasor is determined; and a foil voltage present between the respective foil and ground potential is detected and a corresponding first foil voltage phasor is determined; at a second instant, for each of the phases: a second reference voltage phasor is determined; the foil voltage is detected and a second foil voltage phasor is determined; for each capacitor bushing: a loss factor change is calculated based on the respective reference voltages and foil phasors and those of the adjacent capacitive bushing; and a monitoring signal is generated based on a comparison of the loss factor and a tolerance value.

Abstract: A method provides for usage planning of electrical operating equipment of an electrical system. Here, a future instant is predetermined. Also, for each of the electrical operating equipment: first and second parameter data respectively describing its technical nature and relevance are determined; its characteristic value data are determined; its predicted state index representing its predicted state for the future instant is determined using a first mathematical rule from its first parameter data and its characteristic value data; its criticality index is determined using a second mathematical rule from its second parameter data; and its expanded state index representing its predicted risk analysis is determined using a third mathematical rule from its state index and its criticality index. For the electrical system, a predictive assessment of stability and/or serviceability for the future instant is carried out on the basis of the expanded state index.

Abstract: Transformers are in a parallel circuit in which a tap changer with a control sensor is associated with each of the transformers and all control sensors are connected together by a communications connection. Each control sensor generates a measurement that is transferred by the communications connection. A measurement is generated with each of the control sensors, and at least one of the measurements of the control sensors of the transformers by the communications connection is transferred to N?1 control sensors. Then a controlling deviation caused by a circuit reactive current is calculated for each control sensor on the basis of the measurements of the control sensors. Finally the tap changer associated with each transformer is actuated by the respective control sensor as a function of the calculated controlling deviation such that minimization of the circuit reactive current is carried out for the respective transformer.

Abstract: An apparatus (1) for detecting gas (4) in a high-voltage device (3) filled with an insulating medium (2) comprises an inlet (5) for introducing a carrier gas (16) and an outlet (6) for discharging a carrier gas (16); at least one gas sensor (12) for detecting a gas (4); a first pump (9) for conveying the carrier gas (16) in the apparatus (1); a membrane (13) which at least consists of at least one semipermeable material, is at least partially surrounded by the insulating medium (2) and is at least partially subjected to a flow of the carrier gas (16); a second pump (10) for conveying the carrier gas (16) into the apparatus (1) and for conveying the carrier gas (16) out of the apparatus (1); wherein there is no valve which can be used to convey the carrier gas (16) into the apparatus (1) or out of the apparatus (1).

Abstract: Disclosed is a device and method for reducing network feedback during operation of an electric-arc furnace (10). The electric-arc furnace (10) has three lines (7) with one electrode (4) each. A sensor (15) for measuring the currently flowing current and a sensor (16) for measuring the currently applied voltage are provided in each line. A control and regulating unit (30) calculates an electrical actual value (Eist1, Eist2, Eist3). A semiconductor tap changer (20) is assigned to the furnace transformer (6) such that, by suitably selecting three target winding taps (TSOLL1, TSOLL2, TSOLL3) of a primary side (P) of the furnace transformer (6), a target current (IS1, IS2, IS3) is adjustable in each line (7).

Abstract: A method for controlling the parallel running of a plurality of transformers T1, T2, . . . , TN) in a parallel circuit (10) is disclosed, wherein each of the transformers (T1, T2, . . . , TN) is assigned a measuring/control device (12) and all the measuring/control devices (12) are connected to one another via a communication connection (16). In the absence of a standby signal of at least one measuring/control device (12), interruption (16) of the communication (14) is displayed. The measured values determined at the time (t) of the interruption remain constant for the duration of the interruption (16) and are also included in the calculation of the control errors during the interruption (16), in order to minimise a circuit reactive current of the transformers (T1, T2, . . . , TN).

Abstract: A three-phase alternating current mains has capacitor bushings that each have a conductor connected with one of the mains lines of the alternating current mains and an electrically conductive lining surrounding the conductor. These bushings are monitored by first determining an upper capacitance and a lower capacitance for each bushing and then detecting a measured voltage between the respective lining and a ground potential at each capacitor bushing. An actual capacitance for each capacitor bushing is calculated that depends on the respective measured voltage and the respective lower capacitance as well as on the measured voltage, the lower capacitance, and the upper capacitance of one of the other capacitor bushings. For each capacitor bushing the respective upper capacitance is compared with the respective actual capacitance and a monitoring signal is generated that is dependent on the results of the capacitance comparison.

Abstract: The invention relates to a method for regulating the voltage of a transformer (1) having different winding taps (3). The problem addressed by the invention is that of providing a method with which different load flow directions can be regulated with conventional transformers (1) and voltage regulators (7) in order to ensure a safe and reliable supply of voltage. The general inventive concept consists in determining, using a method in which a quadrant system (11) is used, the phase angle of the conduction current (I) and thus the load flow direction, thereby preventing deviation from the voltage range as a result of power input that is too high, by controlling the load tap changer (4).

Abstract: An apparatus (1) for detecting gas (4) in a high-voltage device (3) filled with an insulating medium (2) comprises an inlet (5) for introducing a carrier gas (16) and an outlet (6) for discharging a carrier gas (16); at least one gas sensor (12) for detecting a gas (4); a first pump (9) for conveying the carrier gas (16) in the apparatus (1); a membrane (13) which at least consists of at least one semipermeable material, is at least partially surrounded by the insulating medium (2) and is at least partially subjected to a flow of the carrier gas (16); a second pump (10) for conveying the carrier gas (16) into the apparatus (1) and for conveying the carrier gas (16) out of the apparatus (1); wherein there is no valve which can be used to convey the carrier gas (16) into the apparatus (1) or out of the apparatus (1).

Abstract: A method for monitoring capacitor bushings (2a, 2b, 2c) for a three-phase AC system, wherein each capacitor bushing (2a, 2b, 2c) has a conductor (4), which is connected to one of the system lines (5a, 5b, 5c) of the AC system, and an electrically conductive lining (3) that surrounds the conductor (4), comprises the steps that—an upper capacitance (C0a, C0b, C0c) and a lower capacitance (C1a, C1b, C1c) are ascertained for each capacitor bushing (2a, 2b, 2c); —a measured voltage (U1a, U1b, U1c) is detected at each capacitor bushing (2a, 2b, 2c), which measured voltage is present between the respective lining (3) and an earth potential (13); —an actual capacitance (C0a?, C0b?, C0c?) is computed for each capacitor bushing (2a, 2b, 2c), which actual capacitance is dependent on the respective measured voltage (U1a, U1b, U1c), the respective lower capacitance (C1a, C1b, C1c) and on the measured voltage (U1b, U1c, U1a), the lower capacitance (C1b, C1c, C1a) and the upper capacitance (C0b, C0c, C0a) of one of the othe

Abstract: The invention relates to a control transformer that is designed as a phase-shifting transformer, wherein semiconductor switching components are provided for each phase at a regulating winding with several partial windings. According to the invention, an additional connecting line with an additional electronic switching component is provided in each phase wherein each of these connecting lines connects a module of the respective phase with the end of the main winding of the adjacent phase.

Abstract: The invention relates to a power transformer with electronic components. The aim of the invention is to arrange the energy supply of the electronic components of a power transformer closer to the components and thus eliminate the disadvantages of the prior art. According to the invention, a stray field collector is brought into a stray field of the power transformer, whereby a voltage is generated.

Abstract: Disclosed are an apparatus and method for process-based power regulation of an electric arc furnace (10). A plurality of sensor types (15, 16, 17) detect presently active operating parameters of the electric arc furnace (10) in dependence on time. From the measured values, a control and regulating unit (30) determines the necessity of whether to switch other winding taps (TS1 . . . TSN) of the primary side (6P) of the furnace transformer (6) by a semiconductor tap changer (20) in order to effect a modified electrical power to prevent thermal and/or mechanical damages to the electric arc furnace (10).