Simulation Design And Dynamic Testing Of Microwave Sulfur Lamp

Microwave sulfur lamp was a new light source developed in the 1990'last century. It's a kind of electrodeless electrical light source which producing light by microwave energy inciting the argon and sulfur in the resonator to generate plasma .Compared with other light sources, microwave sulfur lamp light has many features such as high efficiency and good color performance, high luminous flux, green and environment protection, so it is suitable for large indoor lighting and outdoor lighting. Midea company has independently carried out the development of microwave sulfur lamp which has basically reached the International level. But due to the cost, heat elimination, stability and so on, have constrained its development, led to the t microwave sulfur lamp can not be widely used until now. This paper is based on the previous research of microwave sulfur lamp by Midea company. The background and the development at home and abroad of microwave sulfur lamp was described and the composition structure of the lamp and the role of all part are also Detail elaborated in this paper. In addition the mechanism of the illumination has researched. Main contents of this article include the following aspects:First, simulate and optimize the RF system of Microwave sulfur lamp at the cool state. From the distribution of electromagnetic field in the resonator, we can judge the mode is TE111. the reason of burning the resonator cavity is analyzed. Through optimizing the height of resonator, the electric field around the lamp reached to the maximum (3722V/m), when the frequency is 2.458GHz and the height is 131.5mm. Optimizing the size of the tuning block to gain the best size: width 21mm, thickness 9.5mm, height 40mm, for that the electric field around the lamp reach to 3788V/m.Second, measure the microwave sulfur lamp dynamically in the thermal state. According to the input the voltage standing wave ratio (VSWR) and the emitting principle of the lamp, the whole working process of the lamp can be divided into four phases as follows: preparation phase, quick discharge phase, sulfur plasma lighting phase and stable phase. From analysis of the result gain that the reflection of microwave energy is large in phases of preparation and quick discharge, at which will most likely damage the magnetron. We propose to use switching power to replace two-transformer power for the present product's efficiency is low and it is hard to distribution heat. From the test we find that the performance of microwave sulfur lamp is better when powered by the switching power.Third, simulate the microwave sulfur lamp at the thermal state. The thermal state simulation is based on the parameter VSWR from the thermal state test. If the result of simulation is corresponding to the test result, then the parameter is the plasma equivalent parameter. We gain the equivalent parameter of plasma: plasma frequency 9.5GHz, collision frequency 12GHz. At last, we explored the best condition for the minimum reflection coefficient of microwave sulfur lamp.