Hubbell Limited

General Electric Technology Gmbh

Hubble Incorporated

Timothy J Fawcett

Neil S Fore

Mark R Draper

Simon Kidd

Paul Aston

Antoine Garcia

A protection relay connection assembly () for connecting a current transformer () and/or a voltage transformer () of an electrical network () to a protection relay () is provided. The protection relay connection assembly () includes a protection relay data acquisition board () and a protection relay connector (). The protection relay data acquisition board () includes a first current mating member () connectable to a current measurement sensor (), the current measurement sensor () being connectable in use to the protection relay () and/or a first voltage mating member () connectable to a voltage measurement sensor (), the voltage measurement sensor () being connectable in use to the protection relay (). The protection relay connector () includes a second current mating member () connectable to the current transformer () and/or a second voltage mating member () connectable to the voltage transformer (). The first current mating member () and the second current mating member () are selectively mateable with one another to permit a measured current waveform of the electrical network () to be transmitted from the current transformer () to the protection relay (). The first voltage mating member () and the second voltage mating member () are shaped to be selectively mateable with one another to permit a measured voltage waveform of the electrical network () to be transmitted from the voltage transformer () to the protection relay (). Wherein the first current mating member () is shaped to prevent mating of the first current mating member () with the second voltage mating member (), and the first voltage mating member () is shaped to prevent mating of the first voltage mating member () with the second current mating member ().

Or relating to protection relays

In the field of power distribution networks, a digital output circuit, for controlling an item of equipment within a power distribution network, comprises a switch element openable and closeable to selectively permit the flow of current to an item of equipment being controlled in use by the digital output circuit. The digital output circuit also includes a current acquisition circuit to measure the current flowing through the switch element. In addition, the digital output circuit includes a condition monitoring circuit that is arranged in communication with the current acquisition circuit. The condition monitoring circuit is configured to record the measured current flowing through the switch element as the switch element closes and thereby establish a switch element closing signature.

Or relating to digital output circuits

A method and apparatus for characterizing a three phase transformer () using a single phase power supply (). Pairs of input terminals (H-H) of the transformer are sequentially energized for each energization and the voltage between pairs of output terminals (x-x) of the transformer are measured. Measured voltages are processed in order to characterize the winding configuration of the transformer. Either simultaneously or subsequently the presence of neutrals on the primary and/or secondary side of the transformer are identified to enable the winding configuration to be further characterized. Subsequently any phase displacement of the transformer is determined. The apparatus comprises means () for selectively applying a single phase power supply () to pairs of terminals (H-H) on the transformer () and for measuring voltages between pairs of terminals (x-x) of the transformer and for measuring phase difference between the primary and secondary sides of the transformer all under automatic control of a control means () which includes a processing means to process measured voltages and phase differences in order to characterize the transformer.

Method and apparatus for characterising a three phase transformer using a single phase power supply

A process and an apparatus for measuring the impedance of a capacitive sample and thereby determining the leakage impedance and the loss angle. To suppress the effects of ambient power frequency fields coupling onto the test object, measuring frequencies on either side of the line frequency are imposed onto the test object. The voltage and current are captured using a detection system. These signals are digitised and processed using a computer to determine the real and imaginary voltages and currents at the two test frequencies. These components are then analysed to calculate the leakage impedance and phase angle at the two frequencies. By applying a linear interpolation between the two points, the impedance and loss angle at the line frequency can be measured.

Method and apparatus for testing an electrical component

A voltage measurement system is provided which concurrently measures peak voltage and root mean square voltage. The voltage measurement system employs a digital peak detection circuit for peak voltage measurement. The voltage measurement system employs a memory device for storing samples of a voltage signal at predetermined intervals corresponding to a line frequency multiplication factor. The samples in the memory device are then used to calculate root mean square voltage.

System for concurrent digital measurement of peak voltage and RMS voltage in high voltage system

A partial discharge measurement system is provided which comprises a digital peak detection circuit. The partial discharge measurement system digitizes and detects both positive and negative slopes of a signal from an electrical device being tested. The partial discharge measurement system controls the shape of pulse capture windows in accordance with different modes of operation, and controls the timing of pulse data capture depending on the mode of operation and the polarity of the signal.

System for measuring partial discharge using digital peak detection

A breakdown voltage measurement system is provided which employs a digital peak detection circuit for peak voltage measurement. The breakdown voltage measurement system employs a voltage memory device for storing successive peak values obtained from the digital peak detection circuit. The breakdown voltage measurement system is programmable to commence searching of stored peak values following breakdown of a sample electrical device being tested to determine a voltage measurement immediately before the breakdown occurred.

System for digital measurement of breakdown voltage of high voltage samples

A pulse discharge site location (PDSL) system is provided which captures pulses on a conductor without requiring the triggering functions of an oscilloscope. The PDSL system comprises a pulse discharge measurement (PDM) system and is programmed to store the data captured by the PDM system in a reference buffer corresponding in size to the propagation time of a pulse along the length of the conductor. Samples of the captured pulses are scanned to locate the peaks of pulses above a selected noise level. These pulses are stored into a temporary working buffer, along with a selected number of samples, normalized and then added to the reference buffer. The reference buffer provides a statistical average of pulse activity. Primary pulses and their second and higher order reflections, as well as transient interference pulses and radio frequency interference, are indicated at the beginning and end of the reference buffer. Reflections of first reflected pulses from fault sites in a conductor are represented in the remaining portion of the reference buffer. Fault site distances from the end of the cable can be determined due to the proportional dimension of the reference buffer with respect to the length of the cable and cable propagation time.

Growing community of inventors

Runcorn, United Kingdom

Timothy J Fawcett