The high voltage cascade SVG device is composed of several H-bridge modules and is in suspension due to its high voltage level and insulation requirements as well as ungrouneded H-bridge module. IGBT can

in case of operation

generate a large amount of heat

the substrate of the switching device therefore needs to be close to the surface of the radiator for better heat dissipation

but at the same time

it also forms a large distributed capacitance. The radiator which is affected by IGBT switching voltage and distributed capacitance will induce voltage and the suspension radiator is equivalent to electromagnetic radiation source

which can create serious electromagnetic interference. In this paper

the harm of radiator suspension is analyzed by setting up a near-field coupling model of H-bridge module

and a simulation model is set up for verification. Finally

a test platform is built to study the influence of radiator suspension and equipotential connection on module electromagnetic interference. Through multi-dimensional comparison

it is finally concluded that the equipotential connection at the DC midpoint of radiator was the best way.