CONTROL DEVICE COMPRISING A FREQUENCY CONVERTER AND COMPENSATION OF LINE REFLECTIONS

摘要

The invention relates, inter alia, to a control device (10) for controlling an electric device (60) with a frequency converter (40) for generating a pulse-width modulated output voltage (Ua) for the electric device. The aim of the invention is to prevent or reduce the problem of voltage overshoots that are caused by reflection. According to the invention, this is achieved in that the control device has a measuring device (20) which can be indirectly or directly connected to terminal contacts (61, 62) of the electric device, to terminal contacts (41, 42) of the frequency converter, or to a connecting line (50) between the electric device and the frequency converter and which is suitable for measuring a measured variable (U) that indirectly or directly indicates line reflections, thereby forming measured values (M), and transmitting the measured values to a control device. The control device is suitable for analyzing the measured values for the presence of a voltage overshoot that is caused by reflection and changing the voltage that is applied to the terminal contacts of the electric device in the event that a voltage overshoot that is caused by reflection is determined. The applied voltage can be changed, for example, by a controllable damping member, a controllable impulse generator, or a change of the fundamental frequency of the frequency converter.