High Voltage Testing
High voltage is found in a wide variety of places including power distribution networks, components that detect light or particles (for example photo-multipliers and electron multipliers), components that emit light or particles (such as halogen globes, and cathode ray tubes), transformers, high powered receivers and transmitters, automotive ignition systems as well as in a variety of natural occurring phenomena like lightening and objects that exhibit electrostatic behavior. The use and study of high-voltage is important as it is crucial to the understanding how electricity can be transmitted, a key parameter in power distribution, as well as how components perform under different conditions.
Spectrum digitizers are ideally suited for use in high voltage test systems as they are available with a wide range of sampling rates, bandwidths and resolutions. For example, high voltage impulse testing typically requires large dynamic range and maximum sensitivity. Spectrum offers high-resolution 14 and 16 bit digitizers that can capture and analyze signals that have frequency content going as high as 250 MHz. These high-resolution cards deliver outstanding signal-to-noise ratio's (up to 72 dB) and spurious free dynamic range (of up to 90 dB) so that the smallest signal variations can be detected and analyzed. Furthermore, they have fully buffered front-end circuitry and calibrated gain ranges making it easy to adjust the full scale input range to match the signal being measured. For even higher frequencies 8 bit digitizers are available that offer up to 5 GS/s sampling rates and 1.5 GHz bandwidth.
The digitizers are available in a number of form factors including PCI, PCIe, PXI and LXI. The PCI and PCIe cards can be installed directly in a desk top PC while the LXI instruments can be used with a Notebook or anywhere that you can connect to a local area network (LAN). With large on-board memories (up to 4 Gsamples/card) and advanced streaming and readout modes the digitizers are ideal for capturing long and complex signals. Streaming data from the digitizer to a storage system also allows the archiving of hours of information. Spectrum's SBench 6 software can provide full instrumentation control as well as an easy way to view, store and qualify signals. FFT's are available for frequency domain analysis and parametric calculations can be used to measure key signal characteristics like amplitude, slope, pulse width and more.
Matching Card Families
130 MS/s - 400 MS/s
14 Bit 16 Bit
1.25 GS/s - 5 GS/s
5 MS/s - 125 MS/s
Transformator Windows Analysis
Power system failures are often related to mechanical deformation in transformer windings. Winding distortion can lead to insulation deterioration which in turn can produce partial discharge and gassing type events. At the Xi’an Jiaotong University, in Xi’an, China, they are using a Spectrum M2i.4912 Digitizer and M2i.6011 AWG to perform Swept Frequency Response Analysis (SFRA) while researching the main causes of transformer failure in high-voltage power systems. IEEE members can read the full story here:IEEE Paper
Initiation of Lightening Events
At the Electrical and Computer Engineering Department, Duke University, USA they are studying the electric fields that develop with a natural lightening leader. They have developed a 10–250 MHz broadband lightning interferometer that allows them to measure the very high frequency (VHF) radio emissions from the tip of a positive cloud-to-ground (CG) leader. Research papers on the work, that includes the use of an M4i.4451-x8, 500 MS/s, 14-bit Digitizer, 500 MS/s, 14-bit Digitizer, are available here and here:Research Paper
Partial Discharge (PD) Detection
Using an antenna array for non-contact Partial Discharge (PD) detection has become a useful technique for in air-insulated substation (AIS) monitoring. At the State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, China, they are using two synchronized Spectrum M4i.2221-x8 digitizers to simultaneously collect signals from four antenna at a sampling rate of 2.5 GS/s. The white paper shows time difference localization techniques and how they can be classified as maximum-likelihood (ML) and least squares (LS) estimatorsWhite Paper
Swept Frequency Response Analysis
Power system failures are often related to mechanical deformation in transformer windings. Winding distortion can lead to insulation deterioration which in turn can produce partial discharge and gassing type events. At the Xi’an Jiaotong University, in Xi’an, China, they are using a Spectrum M2i.4912 Digitizer and M2i.6011 AWG to perform Swept Frequency Response Analysis (SFRA) while researching the main causes of transformer failure in high-voltage power systems. IEEE members can read the full story here:Research Paper (IEEE Login)