Inductive power transfer control

Method of detecting an operating condition of a secondary side of an inductive power transfer system, comprising the steps:

• measuring at least one electric variable at a primary side of the inductive power transfer system which is dynamically coupled to the operating condition at the secondary side of the inductive power transfer system;
• executing a first analysis of the at least one electric variable over time at the primary side of the inductive power transfer system for detection of the operating condition at the secondary side of the inductive power transfer system without use of measurement data measurable at the secondary side of the inductive power transfer system;
• determining a rate of change of the at least one electric variable at the primary side of the inductive power transfer system;
• and
• executing the first analysis by analyzing the rate of change of the at least one variable at the primary side of the inductive power transfer system using at least one threshold which is a fixed threshold.