摘要
紫外探测技术在军事和民用领域发挥着越来越重要的作用。其中电力部门主要用来检测电晕放电,及时准确地检测电晕放电的位置和强弱对保证电力系统可靠运行和减少人身及设备的损坏有重要的意义。
常规的电晕照相机在白天不能有效地探测到电晕活动。本文对基于紫外CCD传感器的硬件电路进行设计,将其应用于紫外电晕检测系统中可使该系统不受太阳辐射的影响,24小时全天候工作,可对电晕放电进行准确地探测和定位,无图像偏差。
结合紫外CCD—CCD180-512-SFT的工作原理,详细介绍了利用现场可编程逻辑阵列(FPGA)设计CCD驱动时序,并在理论上分析了CCD的噪声种类和产生原因,简单介绍了对于各种噪声的消除方法。结合KTC噪声特性,对相关双采样电路进行了详细分析。设计了CCD视频信号处理电路,包括前置预放、输出放大、箝位放大、A/D转换、数据缓存等模块,其中,数据缓存器由Altera新一代FPGA—CycloneⅡ系列EP2C35F484C6内嵌的RAM块生成。实现了高可靠性的CCD视频信号的处理。最后,分析了目前设计中的不足之处,提出部分改进意见。
Ultraviolet technology of detecting is playing a more and more important role in the field of military affairs and civil application in modern society. The main purpose for electric power department is to examine the corona discharge. To detect the position and intensity of corona discharge in time is significant for the steady going of electric power system and the decrease of facilities' destruction.
Normal corona camera can't detect the activity of corona effectively in the daytime. The hardware circuit based on ultraviolet CCD is designed. Apply this hardware circuit to ultraviolet corona detecting system can avoid the influence of solar radiation and detect the corona discharge effectively without image warp.
According to the principle of CCD180-512-SFT, a new approach using filed programmable gate array (FPGA) to achieve the schedule circuit is presented. All kinds of noise of CCD are analyzed, and how to eliminate it is introduced. According to the characteristic of KTC noise, the correlated double sampling circuit is particularly analyzed. CCD video signal processing circuits are designed independently, such as front amplifier, output amplifier, clam amplifier, A/D and FIFO. FIFO is built from embedded M4K memory blocks of Altera Cyclone II device-EP2C35F484C6. The CCD video processing circuits are high reliable. Finally, some advice is given for the design according to the deficiency.
引文
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