Measurement and analysis of radiated electromagnetic fields around the pulsed power supplies

The pulsed power supply generates great pulse current that would reach several hundreds thousands amperes. Thereby, the measurement of the spatial and temporal distributions of the radiated electromagnetic fields could be useful to analyze the electromagnetic interference to the electronic apparatuses around the power supply. Two types of pulsed power supplies are focused. They both use capacities as their energy storage modules, while one type of supply uses spark gap switches, and another one uses silicon controlled rectifier. Several B-dot loop probes, D-dot probes and a digital oscilloscope, with enough sampling rate and memory depth, are used to measure the magnetic and electric fields around the supplies separately. The magnetic fields near the switches are focused especially. The probe proofreading experiment is also developed to verify the probe coefficients. It comes out that the electric field is very small. The comparisons between the two pulsed power supplies have been made, and the results show that the radiation magnetic field of the pulsed power supply using spark gap switches owns the spectrum that could reach up to 10 MHz, while the other one is only less than 1 MHz.