基于Ovation DCS的基本算法组态解决二维拟合插值问题  

RESOLVATION OF INTERPOLATION PROBLEM IN TWO-DIMENSIONAL FITTING BASED ON DCS BASIC ALGORITHM CONFIGURATION MADE FROM EMERSON COTROL SYSTEM CORP IN USA

作　　者：张雄[1] 易凡[1] 张晓东[1] 陈又申[2] 谢同琪[2] 

机构地区：[1]艾默生控制系统(上海)有限公司,上海201206 [2]宝山钢铁股份有限公司电厂,上海200941

出　　处：《热力发电》2011年第9期26-29,41,共5页Thermal Power Generation

摘　　要：在对宝山钢铁股份有限公司电厂(宝钢电厂)4号机组辅机故障减负荷(RB)试验前的控制逻辑优化过程中,发现送风机出口风压计算逻辑存在设计缺陷。该风压计算是一个典型的二维曲面拟合问题,由于美国艾默生过程控制有限公司的Ovation DCS中无二维曲面拟合函数可用于送风风压计算,因此采用一维插值函数乘以修正系数的方法,其计算结果与设计值偏差较大。为此,提出了对送风机风压设计曲线的上限曲线和下限曲线分别进行分段拟合后,再在另一维度上对2条拟合曲线进行线性插值计算,以及对送风机风压设计曲线的上限曲线和下限曲线在2个维度上进行双线性插值计算2种改进逻辑组态方法。采用Ovation DCS虚拟控制器对原有算法和2种改进算法进行仿真结果表明,2种改进算法均显著提高了计算的准确性。In the optimization process of control logic before run back test of unit no.4 in Shanghai Baogang Power Plant,it is discovered that the design defects existing in calculating logic for outlet air pressure of the forced draft fan.The calculation of air pressure is a typical problem in two-dimensional curved surface fitting,owing to there isn＇t two-dimensional curved surface fitting functions in Ovation DCS made from Emerson Control System Corp in USA can be used to calculate the air pressure of forced draft fan,therefore,a method of one-dimensional interpolation function multiplied by the correction coefficient has been adopted,however,a large deviation exists between the calculated result and the designed value.For this two improvement methods for logic cofiguration have been put forward,i.e.the one method is as follows：after carrying out sectionally fitting for the upper limiting curve and the lower limiting curve of the designed curves for the air pressure of forced draft fan,the linear interpolation calculation has to be conducted again according to other one-dimension;the another method is as in the following：the upper limiting curve and lower limiting curve based on the designed curves of air pressure in the forced draft fan have to carry out linear interpolation calculation according to two dimensions.Adopting Ovation DCS virtual controller,emulation has been carried out for the original algorithm and two improved algorithms,all have substantially enhanced the accuracy of calculation.

关 键 词：OVATION DCS 虚拟控制器 一维 二维 曲线拟合 线性插值 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]