Abstract: An item of electrical equipment comprises at least one tap winding having winding taps and at least one partial winding, and a tap changer for changing a transmission ratio, an impedance or a voltage, used for excitation of the item of electrical equipment. The tap changer comprises a first module for connecting the winding taps of the at least one winding tap to one another and a second module for rapid switching-in, switching-out or bypassing of the at least one partial winding. The second module comprises at least one submodule having semiconductor switching elements, and a bypass switch.

Abstract: A method monitors at least one item of inductive equipment. The method includes: performing an operation of recording real-time data relating to a current condition of the at least one item of inductive equipment; performing an operation of transferring the recorded real-time data to a monitoring unit assigned to the at least one item of equipment; performing an operation of ascertaining a condition factor of the at least one item of inductive equipment based on the real-time data; performing an operation of ascertaining a failure rate for the at least one item of inductive equipment on the basis of the condition factor; and performing an operation of determining a maximum permitted hotspot temperature on the basis of the failure rate.

Abstract: A method for adapting a target voltage value for voltage control of a tap-changing transformer by an on-load tap changer is provided. The method includes determining a reverse power flow on a low-voltage side of the tap-changing transformer by measuring a current and a voltage. The on-load tap changer is actuated from a current tap position n to a further tap position. A voltage of a current is measured in the further tap position. A value m is determined from powers of different tap positions, and the determined value m is used as a gradient for a first section of a straight line of the target voltage value.

Abstract: A method changes a transformation ratio, an impedance, or a voltage used for excitation of an item of electrical equipment. The item of electrical equipment includes: a tap winding having winding taps and a partial winding; and a tap changer that changes the transformation ratio, impedance, or voltage used for excitation. The tap changer has a first module that connects the winding taps to one another; and a second module with semiconductor switching elements for the switching-in, switching-out or bypassing of the partial winding. The method includes: receiving a request to change the transformation ratio, the impedance, or the voltage; checking a relevant parameter; and changing the transformation ratio, the impedance, or the voltage either by way of the first module or by way of the second module depending on the check of the at least one relevant parameter.

Abstract: A device (1) for monitoring an on-load tap changer (2), comprising: —a motor drive (4); —a monitoring unit (11); and —a sensor (6) for acquiring an acoustic signal; wherein —the monitoring unit (11) determines a torque curve in the on-load tap changer (2) on the basis of a torque curve on the motor drive (4) and the acoustic signal of the sensor (6).

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).