System and method to generate multi-level voltage pulses for electrical insulation testing

摘要

A system and method to generate high voltage pulses for testing of electrical insulation is presented. The system is comprised of multiple bridges in series that are connected across the insulation through an output inductor. The switching of the bridges are timed to allow a resonant half-cycle of current through the output inductor and the effective capacitance of the insulation which results in a transition of the voltage across the insulation from one level to another. The sequence of switching of the bridges is swapped intermittently such that the dc links of the bridges are substantially kept balanced. In one embodiment, only the dc link of the first bridge is supplied from an external source, while the other bridges are fed via the chain of series bridges from the first bridge through the switching operation of the circuit.