A resonant speed controller for injection of a sinusoidal speed excitation in frequency response analysis of variable speed pump drives

In this paper an approach for adapting a speed controller in order to perform a superposition of the speed of a circulating pump with a sinusoidal excitation is presented. In various applications the injection of a sinusoidal signal can be used for frequency response analysis. In this case the speed control of a circulating pump is adapted in order to perform a speed excitation which can be used for the identification of the pipeline network the pump is embedded in. As the original speed control was implemented with a PI-controller in order to control the operating point of the pump, the control is adapted by adding a resonant controller in parallel to the PI-controller in order to maintain a transfer function similar to the original one while providing an improved behaviour regarding the injection of the speed excitation.