A kind of on-line insulation detection method based on ladder-shape signal injection for ship´s engine room automation equipment

In view of on-line insulation detection requirements of ship´s engine room automation equipment, which is not be attached attention usually, a kind of on-line insulation detection method based on ladder-shape signal injection is studied. To simplify the hardware configuration, the generator circuitry of injection signal and logical circuitry are designed based on CPLD, and then the insulation detection circuitry and processing circuitry are worked out, in which the criterion is based on the reference voltage comparison. A prototype is developed and functional tests are conducted. Experiment result indicates technology requirement is met and the detecting scheme is feasible.