Method for contactless power transmission between a stationary part and a movable part, electrical power supply circuit and contactless connection system including the electrical power supply circuit

Abstract

Method for contactless power transmission between a stationary part () and a movable part () and electrical power supply circuit () for implementing the method comprising an air-coupled transformer () provided with a primary resonant circuit with a primary coil () supported by the stationary part and a secondary resonant circuit with a secondary coil () facing the primary resonant circuit and supported by the movable part. The primary resonant circuit is fed with an alternating primary electrical voltage (V) which causes a primary electrical current (I) to circulate. The primary electrical current (I) induces in turn in the secondary resonant circuit an alternating secondary electrical voltage (V) which causes a secondary electrical current (I) to circulate. An electrical variable influencing the achievement of the resonance condition is adjusted, for example the frequency (F) of the primary electrical voltage, in such a way to operate in a resonance condition. The distance (d) between the stationary part and the movable part is determined as a function of a value of such electrical variable. A contactless connection system includes the stationary and movable parts and the electrical power supply circuit.