Power Distribution System : load modeling of a Power Distribution System (PDS) for a medical imaging processor

Abstract

Philips Healthcare is researching and developing a new power distribution architecture that is intended to power different medical equipment, such as computed tomography, radiography, ultrasound and interventional X-ray equipment. The objective of this new architecture is to improve the safety in using these medical devices during operations, but it is further intended to power other non-medical devices as well. Some parts of the new architecture, like the power source and the Power Distribution System (PDS) have already been designed by Philips and former students. However, the load model that is connected to the system still needs to be tested and validated in order to have the whole architecture completed. Therefore, this report contains the results obtained after six months studying the loads characteristics of the system. A computational model was designed in LTspice IV software to predict the behavior of different loads when connected to the PDS. In the model, the load was represented by electronic components described by values that change over time. These values are set by the user with the purpose of analyzing the variations of voltage and currents during the load operation time, and they were carefully chosen in order to provide the results most similar to real life. After simulating, measurements with real loads in the X-Ray laboratory were analyzed and compared with the previous computational results. A validation tool was used to verify the closeness of the simulations to the practical measurements. In preparing and designing the models, an accuracy of 10% between the models and the practical results is expected.