Towards a traceable divider for composite voltage waveforms below 1 kV

In the framework of the European Project 19NRM07 HV-com2 supporting the standardization in high-voltage testing with composite and combined wave shapes, a divider to employ in a test set-up for validation of electrical devices submitted to composite voltages below 1 kV has been developed at the Istituto Nazionale di Ricerca Metrologica (INRIM) and currently is under extensive testing. After a simulation stage, an available divider has been modified to comply with the IEC 60,060 requirements in terms of step response and scale factor. To be suitably fast in replying to step voltages, an adjustment of the components of the low-voltage arm has been made. The divider has been calibrated with traceability to the relevant INRIM National Standards and characterized exploiting its scale factor at different voltages and frequencies. The divider has been then inserted in a set-up with a sinusoidal generator, an impulse generator and coupling–blocking elements to carry out tests at low voltages (below 1 kV) with single voltages. In these tests, the divider showed a satisfactory attitude as converting device and its scale factor is traceable with suitable uncertainty.

New Hydraulic High-Pressure Impulse Generator for Long-Duration Impulse Tests

Water hammer wave is widely applied to test hydraulic components in various areas. A new hydraulic high-pressure impulse generator is presented in this paper in order to provide the standard water hammer wave for long-term usage. A combination of a sleeve and a rotary spool was used to build the impulse generator, and a booster piston was applied to amplify the output pressure. Mathematical models were established using commercial software, and a prototype and a test rig were built based on the simulation results. The experimental results for both single wave and repeated periods show the feasibility of the new design and indicate that the new hydraulic high-pressure impulse generator can be used for long-time impulse tests.