超高壓電流驅動器的熱分析
Thermal analysis of an UHP high current driver
Arjan Kole Philips Centre for Industrial Technology
P.O. Box 218 5600 MB Eindhoven, The Netherlands
Abstract
The design of new electronic devices usually does not involve thermal issues. However for some products it is necessary to include thermal aspects in the design process. Thiscan have major influence on the way the design of the product is developed.
Typically, simulations are made with CFD packages like Flotherm to investigate the thermal performance of the proposed design.
In this approach thermal specialists are involved which do not have to deal with other problems, involving electronics and mechanics. Therefore it is thought that it would be very useful for electrical designers to deal with thermal issues themselves already in the early stages of the design process. Due to the limited thermal
knowledge of electrical designers it is necessary to give them easy applicable tools, which show the thermal consequences of choices made in the design process. Tools are derived from Flotherm simulations but also simpler software is used.
Introduction
The predevelopment office of Lighting Electronics & Gear in Eindhoven develops among other things lamp drivers for Ultra High Pressure lamps. These UHP lamps are used in beamers and whereas beamers tend to become smaller the driver for the lamp has to go through the same traject. In general it can be said that the lamp drivers tend to evolve towards smaller drivers, that dissipate more heat. Together with this, thermal aspects become more important.
The reliability of the components decreases or the functionality of the component decreases or the dissipation of the component increases with higher
temperature, for example in a coil. In the UHP high current driver for both failure mechanisms components can be found.
The goal of the project was to check the thermal feasibility of the design of the UHP high current driver. This has been checked by simulating the temperature distribution with Flotherm. Furthermore modifications of the design are considered on thermal aspects of the UHP driver. Once the Flotherm simulations were finished it was thought that the simulations might not have been necessary if other ‘smart’ tools were used to predict thermal problems, which are developed afterwards.
Flotherm simulation
For the thermal simulation Flotherm was used. A mock-up was used as an example to model the UHP high current driver after.
The mock-up is shown in Figure 1. The resulting Flotherm model is shown in figure
....
Conclusions
Thermal analysis of electronics is not only up to thermal experts, but also electronic and mechanical designers can deal with it.
Without thermal simulations can already partly be concluded whether a concept will not work. The use of statistical techniques enables the designer to investigate a whole area of variations in the design. In Flotherm with the help of the Command Centre it is possible to easily prescribe all simulations necessary to build a so called surface response model.
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