SMOCPro中的阀门饱和处理—dSPdV-6
现在让我们考虑同一个计算，但把该MV的Max Move Size设定为350。与k= 1步时的计算有相同的结果，因此CalcSPHi限依旧卡紧在CalcSPLo。然而，SMOCPro只允许PV移动到750。
|k| PV |SP| OP| dSPdV| IntCalcSPLo |IntCalcSPHi| CalcSPLo |CalcSPHi|
| ------------- |:-------------:| :-----:|
|2| 750 |750 |65| 24 |-570 |1110| 500 |1000|
下一计算还表明高限被放宽到对应的DCS。
下图3以图形的方式显示出这两个方案的结果。在上半部分我们可以看到当SP拥有一个大的（比当前PV与SPLo的差值大，本例中是600）Max Move Size时的影响。在底部我们可以看到Max Move Size =350时的结果。在此情况下SMOCPro执行一次后SP只移动到PV =750。此时dSPdV计算被再次执行且CalcSPHi限被松开。
Figure 3. Illustration of how Max Move Size couples with the dSPdV calculation.
图3：dSPdV计算中的Max Move Size组图示。
例4：样本dSPdV仿真
现在我们利用两个仿真实例来说明dSPdV计算。第一个（下图4）展示了当OPHi限是阀位物理限制时，且不能被违反的情况。dSPdV方法通过调整SPHi限（蓝色的CalcSPHi）以促使OP无法进一步动作。此SPHi修改充当了控制器预防饱和的作用。同时还可以看出只要OP不再触碰限制，dSPdV计算将把CalcSPHi松开回SPHi限。
Figure 4. The dynamic behavior of the dSPdV calculation for the case when the OP limits are physical limits.
图4. 当OP限触碰到物理极限时，dSPdV计算的动态行为。
第二个仿真（下图5）展示了当OP限不是物理限制而是需求限制时的情况。从图中可以清楚地看到在给定的时间段里OP违反了OPHi限。然而，当OP越过OPHi限而处于限制之外时，dSPdV计算通过调整CalcSPHi极限减小，在保证PV带回SP的同时，有效地把OP带回到它的限制内。
Figure 5. The dynamic behavior of the dSPdV calculation for the case when the OP limits are desired limits.
图5. 当OP限触碰到需求极限时，dSPdV计算的动态行为。
建立文件
要（重新）建立在线EXA控制文件，请使用UAPC输出树节点上的Build Files选项卡。当所有必要的设计和配置步骤都已经完成，所有的回路信息都已经调整，变量都已经修订完成时，完成这一步是必须的。
原文：
Now let us consider the same calculation but now let the Max Move Size for the MV be 350. The calculation from step k=1 yields the same result, thus the CalcSPHi limit is still clamped at CalcSPLo. However, SMOCPro only allows the PV to move to 750.
The next calculation also shows that the high limit has been relaxed to its DCS counterpart.
Figure 3 below shows graphically the results from these two scenarios. On the top part we see the effect of having a large (greater than the difference between the current PV and the SPLo, 600 in this current case) Max Move Size on the SP. On the bottom we see the result of having a Max Move Size = 350. In this case, after one SMOCPro execution the SP has only moved to PV = 750. At this point the dSPdV calculation is performed again and the CalcSPHi limit is relaxed.
Example 4. Sample dSPdV simulations.
We now present two simulations exemplifying the dSPdV calculations. The first one (Figure 4 below) shows the case when the OPHi limit is the valve’s physical limit and thus cannot be violated. The dSPdV approach adjusts the SPHi limit (CalcSPHi in blue) to reflect the fact that the OP will not be able to move any further. This SPHi modification serves as windup prevention for the controller. It is also seen that as soon as the OP comes off its limit, the dSPdV calculation relaxes the CalcSPHi back to its SPHi limit.
The second simulation (Figure 5 below) shows the case when the OP limits are not physical ones but rather desired ones. This is evident in the figure since for given periods of time the OP violates the OPHi limit. However, when the OP crosses the OPHi limit and is outside the limit, the dSPdV calculation adjusts the CalcSPHi limit decreasing it to effectively bring the OP back into its limits while at the same time bringing the PV to the SP.
Building Files
To (re)build the online EXA controller file, use the Build Files tab on the UAPC Output tree node. This process must take place after all the necessary design and configuration steps have been fulfilled and all the revisions for the loop information and variables have been finalized.
2016.7.7
