Method for checking electrical insulation between e.g. circuit node of electrical traction system and metallic body structure of electrical system in hybrid car, involves measuring and evaluating applied voltage and quality of insulation

摘要

The method involves producing predetermined voltage (U-gen), and applying the voltage between two circuit parts e.g. circuit node (K) and electrical earth (GND). The applied voltage and quality of electrical insulation are measured and evaluated depending on electrical parameters e.g. measured voltage (U-mess) and measured current (I-mess). Excess voltage i.e. boost voltage, and reduced voltage are produced and applied in two phases, respectively. The voltage and the quality are measured in one of the phases. The excess voltage is larger than the reduced voltage around a factor of 1.2. An independent claim is also included for a circuit device for checking electrical insulation between two circuit parts of an electrical system, comprising a voltage source.