Safe and automated control of experiments with a high voltage construction kit

Summary

For high voltage (HV) experiments in scientific and industrial environments flexibility is a great advantage. For this reason the HV construction kit is very popular for the generation of AC, DC and impulse voltages of up to 260 kV. A modern and flexible alternative AC-source is built with an industrial three-phase frequency converter (FC) controlled by a failsafe Programmable Logic Controller (PLC). Moreover, the FC has the advantage that voltage and frequency can be controlled separately from each other. From the three-phase output, two phases are connected via an insulation transformer and filtering system to the high voltage transformer and the rest of the experimental construction kit. The effective performance of the filtering system also enables partial discharge (PD) measurements according to IEC 60270 with a sensitivity of <1 pC. The failsafe PLC not only controls the FC, but also the safety components of the whole experimental setup. By applying redundancy and using failsafe components a Safety Integrity Level 3 (SIL 3) according to standard EN 61508 can be reached. This also greatly improves the safety of its operators. With a single plug system and linked user interface of the PLC, the flexibility of the experiment setup is still guaranteed. A further advantage of this combination of PLC and FC is that the whole system can be automated for long-term experiments with different functions, e.g. running predefined measurement programs with varying voltage curves or amplitudes, monitoring and temporary grounding or discharging.

Additional informations

Authors

Du Bin, Li Jian, Yao Wei