期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2016
卷号：4
期号：8
页码：19-25
DOI：10.15587/1729-4061.2016.73541
语种：English
出版社：PC Technology Center
摘要：Power electronics and their thermal protection systems that are designed on the basis of modern methods of thermal calculations work efficiently under specified operating conditions in a particular operating range of temperatures and modes beyond which the form of the transition process can change. Consequently, the extent of oscillation in the transition process increases along with the initial voltage and current fluctuations. These changes are dangerous if the boundary values of the component parameters are underestimated due to heating.The study suggests a method of integrated electrothermal calculation in order to ensure thermal protection of pulse converters for electric power by creating combined models of the circuit elements in the form of a system of differential equations. Analysis of the characteristic roots of solutions of the differential equations of the system state in the form of matrix exponentials gives an idea about the nature of the transition process. This allows setting a threshold value of fluctuations and a time frame of the transition process while enabling a heated device. It becomes possible to stabilize the transition process by heating the components and to choose magnetic materials of inductors, taking into account the thermal processes.As a result of this approach, thermal protection of power transformers extends to providing trouble-free operation at non-stationary modes of the components and extreme temperatures; it becomes possible to reduce the complexity and rigidity of the requirements to establishing a time frame for restarting the device.
关键词：equation of the system state;thermal impedance;matrix exponential;electrothermal modeling
