Selftuning sensorless controlled drives

01.05.2007 - 30.09.2010
Research funding project
Controlled induction machine drives at present are considered the working horses of modern industrial applications because of their dynamic properties, robustness, and costs. With the stringent demand to steadily reduce the costs of all industrial components research has focused in the past years on the development of control methods working without speed/position sensor. As turned out from previous research, it is so far only possible to realize speed-sensorless control in the whole operating range including zero flux frequency if the high frequency or transient electrical behavior of the machine is considered. By establishing such a transient excitation in addition to the fundamental wave voltage the transient response of the machine current can be obtained and evaluated. It is modulated due to the inherent saliencies of induction machines caused for example by saturation or slotting. Using appropriate signal processing it is thus possible to estimate the flux and rotor position necessary for the control of the machine. However, all such methods are still limited to laboratory use and are not applied industrially. In the proposed project two of the main problems still existing with zero speed sensorless control will be addressed. One of these main problems is denoted tuning of the control parameters. The design of the machine, the inverter, as well as the kind of excitation has strong influence on the resulting control signal obtained. Thus usually a high number of parameters have to be adjusted in order to set up speed-sensorless control on a new type of induction machine drive. This tuning process up to now is a time consuming task and needs an expert in speed sensorless control to be performed. In the proposed project neural networks together with classical optimization methods and observer approaches will be applied. The final sensorless control is a combination of a fundamental wave method and signal injection method. The goal is to tune the parameters of both methods by an algorithm only supervised by a commissioning engineer using no special test equipment. The second main problem is denoted interference of the different saliencies modulations. Generally there are always flux fixed and rotor fixed saliencies present in standard induction machines. In specific operating ranges the frequencies of those saliencies overlap making it extremely difficult to separate them correctly. This topic will be addressed by applying blind signal separation techniques together with an observer approach. In addition, that one of the two rotor fixed saliencies (slotting, anisotropy) not overlapping in frequency with the saturation saliency will be used to obtain additional information in these critical operating states. In addition, using the developed self tuning and signal separation method the drive should be able to separately track and exploit the dominant stator and rotor fixed saliencies present in standard induction machines and therefore enable speed-sensorless torque as well as speed/position control.

People

Project leader

Project personnel

Institute

Grant funds

  • FWF - Österr. Wissenschaftsfonds (National) Austrian Science Fund (FWF)

Keywords

GermanEnglish
Elektrische Antriebeelectric drives
sensorlossensorless
Inbetriebnahme commissioning

Publications