Method for detecting an electrically conductive foreign body in a region of a device for inductively transmitting electrical energy and device for inductively transmitting electrical energy

• Main Authors: Wechlin Mathias, Asselin Pascal
• Format: Patent
• Language: English
• Published: 18.04.2017
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC EQUIPMENT OR PROPULSION OF ELECTRICALLY-PROPELLEDVEHICLES; ELECTRICITY; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES, IN GENERAL; GENERATION; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; PERFORMING OPERATIONS; SYSTEMS FOR STORING ELECTRIC ENERGY; TRANSPORTING; VEHICLES IN GENERAL

In a method for detecting an electrically conductive foreign body at a device for inductively transmitting electrical energy from a stationary unit having an electrical power supply unit and a primary inductor to a mobile unit having a secondary inductor and an electric load, electrical power is initially fed from the electrical power supply unit into the primary inductor and the feed-in is interrupted. The curve over time of the resulting decay of an electrical operating variable of the primary inductor is measured and at least one parameter of the measured curve is compared with a corresponding parameter of a reference curve in the event of an interruption of the power feed-in into the primary inductor without the presence of an electrically conductive foreign body. The comparison is used to determine whether an electrically conductive foreign body is present in the region of the magnetic field produced by the primary inductor.