Measuring device for use in control device utilized for transmission of power from photovoltaic system into energy supply network, has evaluation unit determining whether inductor is located in saturated state based on measurement signal

摘要

The device has an acoustic sensor (18) arranged in vicinity of an inductor to be monitored for detecting an acoustic signal transmitted by the inductor. A band-pass filter (22) filters out a frequency range in which the inductor is strongly emitted in a saturation state. An evaluation unit (24) determines whether the inductor is located in the saturated state based on a measurement signal that is provided by the sensor and filtered by the filter. The inductor is formed by a reactor coil, a motor control unit or a transformer (14) connected to a voltage source e.g. inverter. Independent claims are also included for the following: (1) a method for detecting a saturation state of an inductor (2) a control method for avoiding a saturation state of an inductor.