半導體照明控制技術研究

Abstract

本研究旨在探討利用迴路熱管(LHP)作為散熱機制的半導體照明燈具，當環境溫度變化(異常狀況)導致散熱不足，LED操作溫度上升而會毀壞晶蕊時，事先知道晶蕊溫度並加以保護不被燒毀，是一必要的機制。本研究重點為：(1)找出晶蕊特性曲線方程式 ，用以預測晶蕊的操作溫度，並利用此穩態值來驗證理論推導的結果。(2)推導LED溫度動態行為，利用系統識別方法驗證之，得到其數學模型，進而瞭解晶蕊溫度的動態變化。(3)保護控制機制設計：分為電壓量測機制以及電流輸入時間控制模式。透過兩者的搭配，後者可以降低LED的操作溫度，前者可以預測當下的晶蕊溫度，當溫度過高時切換操作電流大小，以防止LED損毀。

The main purpose of the research presented is to predict the junction temperature and protect the LED from damage when the air temperature changes that leads to the semiconductor lighting with LHP operates at limited temperature. There are three main points in the research : (1) Find the specific equation of junction to predict the junction temperature and use the steady-state result to check the theoretic result. (2) Derive the theoretic model and system identification to simulate the junction and board temperature in different input heat.(3) Protection control design : including voltage measurement and time control model of input current。 The latter can lower the operating temperature about 5.2℃ to 7.8℃. The former can predict the junction temperature immediately and switch the input current when the junction temperature is too high.