Evaluation and compensation of common mode voltage induced on the differential voltage probe in floating measurement of high voltage power electronics circuit

摘要

The dv/dt in switching operation of high voltage power electronics circuit is increasing in accordance with the development and improvement of power semiconductor device. The voltage in asymmetric circuit results in common mode voltage. This paper evaluates the influence of common mode voltage in the floating voltage measurement with differential voltage probe. This paper also proposes the procedure to compensate the influence of common mode voltage. The common mode voltage superimposed on differential voltage probe output is measured and compensated with the measured residual common mode voltage. The residual common mode voltage can be estimated from the measured drain voltage and common mode rejection ratio (CMRR) characteristics of differential voltage probe. The residual common mode voltage can be sufficiently eliminated with the proposing procedure.