量化误差对电厂主汽温控制品质的影响  

Influence of quantization errors on control quality of main steam temperature control systems of power stations

作　　者：杨平[1] 潘帅[1,2] 

机构地区：[1]上海电力学院电力与自动化工程学院,上海200090 [2]上海大学机电工程与自动化学院,上海200092

出　　处：《华东电力》2008年第11期140-143,共4页East China Electric Power

基　　金：上海市重点实验室"上海市电站自动化技术重点实验室"项目资助(04DZ05901)

摘　　要：量化误差主要与量化单位量成正比。量化单位量的大小取决于A/D或D/A的转换器的位长。量化误差将影响控制系统的准确性指标。对于电站锅炉主汽温控制系统,一般选择12位或16位的A/D或D/A转换器就可满足要求。量化器是典型的非线性环节,可能给控制系统带来自振荡、突变扰动等降低控制品质的影响。一定大小的均匀白噪声的存在,可抵消量化误差的负作用。仿真试验表明,选择偏高精度的A/D转换器,并不意味着可得到较大的控制品质改善。The quantization error is directly proportional to the quantization unit value, while the quantization unit value depends on the number of digit bits of an A/D convertor or a D/A convertor. The accuracy performance of a control system is probably affected by the quantization error. For the main steam temperature system in power stations, it is suitable to select 12 or 16 bits A/D or D/A convertors. The quantizer is a typical non-linear element, and so it may lead to control quality dropping with unexpectedly disturbance of self-oscillation. If there is white noise with proper strength, the bad effect of the quantization error can be cancelled out. The simulation results show that selecting the higher precision A/D convertors does not mean getting great improvement on the control quality.

关 键 词：量化误差 电站自动化 主汽温控制 控制品质 A/D D/A 极限环 

分 类 号：TK323[动力工程及工程热物理—热能工程]