Abstract The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cool- ing media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measure- ments are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated; the trends of efficiency and power dissipation are evidenced.
Keywords Switch Mode Power Supply SMPS, Cold-Plate, Cooling System, Thermal Design
1. Introduction
In recent times, switching regulators are used as replacements for traditional (linear) regulators when high effi- ciency, small size and low weight are required [1]. A Switch-Mode Power Supply (SMPS) is an electronic power supply unit that incorporates a switching regulator to convert electrical power efficiently. Like other power supplies, a SMPS transfers power from a source to a load, while converting voltage and current charac- teristics. Unlike more conventional power supplies, a SMPS minimizes the wasted energy and ideally dissipates no power. This higher efficiency in power conversion is an important advantage of a SMPS, commonly coupled to smaller size and lower weight than a linear supply, due to smaller size and lower weight of the transformer.
How to cite this paper: Casano, G. and Piva, S. (2015) Air-Water Cooling System for Switch-Mode Power Supplies. Journal of Electronics Cooling and Thermal Control, 5, 66-75.
Main characteristics of SMPSs are then high electric efficiency and reduced cooling requirements [2] [3]. However, as usual in power electronics, the power of these SMPSs is increased in time; the heat release is thence once again large and thus efficient cooling systems are needed. Liquid cooling can then become an inter- esting solution, also because it allows a significant size reduction of the equipment in line with the requirements of electronics design [4].
In these equipments the liquid cooling is obtained with cold-plates, consisting of a plate, usually in aluminium, on which are fixed some electronic components and within which one or more hydraulic circuits are obtained for their cooling with water flowing in forced circulation [5].
While it is easy to collocate the active components on a cold plate, the large number of passive components of a SMPS, like condensers, transformers and coils, needs to be placed on a printed circuit board (PCB). It is diffi- cult with a cold plate to maintain the PCB and these passive components at the design temperature, because they are originally developed for air cooling.
In this paper the results are presented for an experimental investigation of heat and fluid flow in a liquid cooled SMPS for TV digital power amplifiers. The objective is to quantify the performance of a new cooling system being designed to dissipate the heat generated by the active and passive electronic components of this SMPS, in order to limit their maximum temperature during operations. The active components are cooled with the liquid cold-plate. For the PCB, hosting the passive components, we create a sealed enclosure over the cold plate, where a forced airflow is driven by small fans (Figure 1). The air flow is used to cool the passive compo- nents; this air flow is cooled with a finned heat sink, in turn cooled by the cold plate. 开关电源水冷却系统英文文献和中文翻译:http://www.youerw.com/fanyi/lunwen_205073.html