Abstract: A high current source (200) for a test system for testing an electric power device (30) comprises a first plurality of first switchable half-bridges (212) and a second plurality of second switchable half-bridges (222), which are connected in parallel and by means of which a test current is redundantly distributed. A control device (280) is designed to control the first and second half-bridges (212, 222) on the basis of an input signal in such a way that an output signal for the test current, which corresponds to the input signal, is applied across a bridge branch (230) between the first switchable half-bridges (212) and the second switchable half-bridges (222).

Abstract: The present invention relates to a method for determining a state of a capacitive voltage transformer which, on its primary side, comprises a capacitive voltage divider having a first capacitor and a second capacitor. The first capacitor has a high-voltage connection for connection to a high voltage) and the second capacitor has a ground connection. A first resonant frequency is determined by way of a plurality of first short-circuit impedance measurements at different frequencies on a secondary side of the capacitive voltage transformer while the high-voltage connection is connected to earth. A second resonant frequency is determined by way of a plurality of second short-circuit impedance measurements at different frequencies on the secondary side of the capacitive voltage transformer while the high-voltage connection is open. A capacitance ratio of the capacitive voltage divider is determined on the basis of the first resonant frequency and the second resonant frequency.

Abstract: To provide a lightweight and robust voltage amplifier and current amplifier for a test device for testing an electrical component, an amplifier is designed to output a test signal at a signal output between a positive output terminal and a negative output terminal. The amplifier includes a first half bridge and a second half bridge. A switching unit is provided, which is designed to connect the first half bridge and the second half bridge in parallel to the signal output in a first operating mode and to connect the first half bridge and the second half bridge in series with the signal output in a second operating mode.

Abstract: The invention relates to a method for personal protection during high-voltage testing on a test object, the method comprising the steps of outputting a high-voltage alternating current for the test object by means of a high-voltage generation device, which has a high-voltage transformer for generating the high-voltage alternating current. The method further has the steps of determining a curve over time of at least one electrical variable at the high-voltage transformer during the output of the high-voltage alternating current, and ending the output of the high-voltage alternating current on the basis of the curve over time of the at least one electrical variable.

Abstract: A flexible test arrangement for performing measurements on a test object. A plurality of safety components, each having a safety module which can be set to active or inactive, and having a ready status which can be set to active or inactive, is provided in a circular test arrangement. Each of the safety components carries out a number of function tests cyclically. As one of the function tests, a cyclical, error-free reception of a data packet is tested. One of the safety components is selected as a bus master which cyclically transmits a bus verification signal in a data packet to the safety component which is adjacent in the direction of transmission, wherein the bus verification signal is relayed by each of the safety components in a data packet, and, when said bus verification signal is received in a data packet, the bus master determines that the circular test arrangement is closed.

Abstract: An apparatus for locating partial discharges in a medium-voltage or high-voltage operating equipment comprises a signal detection device for detecting an electrical signal variable of the operating equipment, a filter device for low-pass filtering of the detected electrical signal variable dependent upon a filter cut-off frequency, a time detection device for detecting a signal propagation time of the low-pass-filtered electrical signal variable, and a comparison device for comparing the detected signal propagation time detected dependent upon the filter cut-off frequency with a reference propagation time for a charge pulse conducted through the operating equipment in order to determine a location of the partial discharge in the operating equipment dependent upon the result of the comparison. Also provided is a method for locating a partial discharge in medium-voltage or high-voltage operating equipment, in particular, using the apparatus.

Abstract: To improve functional security in electric power systems, a fault detector is provided in the electric power system that is connected to the data communication bus and that evaluates streamed values of at least one process parameter. In order to detect an electric fault in the electric power system, the fault detector is arranged to send a fault present indication to the switching element when an electric fault is detected. The fault present indication is sent to and received by the switching element, before the tripping operation of the switching element is triggered upon receipt of the switching command from the automation system, and the switching element triggers the tripping operation of the switching element only when a fault present indication has been received.

Abstract: Test device having a signal input with a positive pin and a negative pin, between which an-input signal may be applied. Test device has a separation unit which is connected to the positive pin and to the negative pin and is configured to separate a positive signal component in the form of a positive track from the input signal, to output said signal component at a first pin, to separate a negative signal component in the form of a negative track from the input signal and to output said signal component at a second pin. The use of the test device to test a control unit of the switching device is described, wherein the test device simulates the switching device, the signal input of the test device is connected to the control unit and the control unit outputs an input signal to the signal input.

Abstract: Test device having a signal input with a positive pin and a negative pin, between which an-input signal may be applied. Test device has a separation unit which is connected to the positive pin and to the negative pin and is configured to separate a positive signal component in the form of a positive track from the input signal, to output said signal component at a first pin, to separate a negative signal component in the form of a negative track from the input signal and to output said signal component at a second pin. The use of the test device to test a control unit of the switching device is described, wherein the test device simulates the switching device, the signal input of the test device is connected to the control unit and the control unit outputs an input signal to the signal input.

Abstract: A transformer test device (10) for testing a transformer (40) has connections (12) for releasably connecting the transformer test device (10) to the transformer (40). The transformer test device (10) has a source (13) for generating a test signal for testing the transformer (40). The transformer test device (10) has a controllable switching means (15) which is connected to the connections (12) during a transformer test for the purpose of short-circuiting at least one winding (42) of the transformer (40).

Abstract: A transformer testing device (10) comprises outputs (31-33) for detachably connecting the transformer testing device to windings of multiple phases of a transformer (50). The transformer testing device (10) further comprises a plurality of sources (21-23), each of which is designed to generate a test signal. The transformer testing device (10) also comprises a switching matrix (40) that is connected between the plurality of sources (21-23) and the outputs (31-33).

Abstract: A method (60) for determining resistances (R1, R2, R3, RN) on a voltage level of a multiphase transformer (10) comprising one winding (u, v, w; U, V, W) for each phase comprises injecting a particular first current into the particular winding (u, v, w; U, V, W); recording a particular first voltage caused by the injected first currents in the plurality of phases; injecting a particular second current into the particular winding (u, v, w; U, V, W), wherein the particular injected second current differs from the particular injected first current in at least one of the plurality of phases; recording a particular second voltage caused by the injected second currents in the plurality of phases, and determining the resistances (R1, R2, R3, RN) on the voltage level on the basis of the injected first and second currents and the recorded first and second voltages. An apparatus (70) for determining resistances (R1, R2, R3, RN) on a voltage level of a multiphase transformer (10) is also proposed.

Abstract: A testing device for an apparatus of an energy system which has inputs that can be connected in a conductive manner to at least one current transformer and at least one voltage transformer. The testing device is designed to apply a first test signal to a secondary side of the voltage transformer and, at the same time, to apply a second test signal to a primary side of the current transformer.

Abstract: A testing device for testing a control unit of a switching device of an electrical switchgear installation. The testing device has a signal input, and to which a controlled current sink is provided, which is connected to the signal input. The controlled current sink shunts an input current from the signal input in order to provide a dynamically adjustable input impedance. A method for testing a control unit of a switching device of a switchgear installation, includes the testing device having a signal input, to which an input voltage may be applied. In the testing device, a controlled current sink shuts an input current from the signal input and thus provides a dynamically adjustable input impedance.

Abstract: In order to demagnetize a transformer core (13, 23) a demagnetization device (40) is detachably connected to a primary side (11) of a transformer (10, 20). An alternating signal is fed to the primary side (11) in order to demagnetize the transformer (10, 20).

Abstract: To ascertain a parameter of a transformer (40) that has a high voltage side (41) and a low voltage side (43), a test signal generated by a source (13) is impressed on the low voltage side (43). A test response of the transformer (40) is recorded. A leakage reactance and/or a leakage inductance of the transformer (40) is determined by an evaluation device (18) of an apparatus (10) on the basis of the test response of the transformer (40).

Abstract: A mobile transformer test device (10) for testing a power transformer (40) has connectors (12) for the detachable connection of the transformer test device (10) to the power transformer (40). The transformer test device (10) has a source (5) for generating a test signal. The mobile transformer test device (10) has an evaluation circuit (6) for determining, based on the test signal and a test response of the power transformer (40), information regarding a B-H curve (50, 60) of the power transformer (40).

Abstract: The following steps are performed in order to test a tap changer of a transformer which tap changer is designed to change a transmission ratio of the transformer: generating a test signal which is supplied to a winding of the transformer and to the tap changer, repeatedly actuating the tap changer in order to change the transmission ratio with each actuation, determining a curve of an electrical measurement variable (I; I1; I2) of the transformer over time (t) for each actuation of the tap changer depending on the test signal filtering the curves in order to prevent at least one of the curves from being output outputting the filtered curves.

Abstract: The aim of the invention is to improve the efficiency and handling of a test device (4) for testing a protection relay (2). This is achieved by a method and a test device (4). A signal (S) is generated in a test device (4), and the signal (S) is applied to the protection relay (2). An adaptation device (X) which can be found in the test device (4) is supplied with a supply voltage (Uv) by an accumulator (5), and the adaptation device (X) supplies a signal generator (G) with an intermediate voltage (Ux), said signal generator generating the signal (S). The use of an accumulator (4) allows fuel-supplied power units to be obviated. The use of an adaptation device (X) allows the supply voltage (Uv) of the accumulator (5) to be converted into small intermediate voltages (Ux) and the small currents of the accumulator (5) to be converted into high currents in order to supply the signal generator (G) for example.

Abstract: A method and test device for testing protection relays, the test device having a signal generator. The signal generator supplies a signal as pulses having pause times, which alternate over time. Signal level is reduced during the pause times and at least one pulse has an amplitude at least higher than one of the preceding pulses. A supply voltage is supplied by an accumulator providing electric energy for generating the pulses. Via the accumulator, a greater mobility and flexibility is ensured, and fuel-fed power units or emergency power units may be omitted. In order to reduce the load (average energy) on the accumulator, the signal generator emits the signal as pulses having pause times. The pulse amplitudes may have an increasing trend to reach a switching threshold. This allows the use of smaller and more compact, which is important for a portable test device.