案例7：加氢脱硫（HDS），混合进料和缓冲罐控制-2

基本情况
打开Simulation节点并选择“Base Case”情景。仔细检查“HDS_Base”被选为控制器。 “Base Case”情景最大化进料，并将液位保持在50。

从图中用户可以看到，在液位被控制在设定点（50）的同时，Feed值被最大化至3185.59。
子控制器不激活
选择方案“Sub-controller inactive（子控制器不激活）”，然后选择HDS_Base控制器。将控制器设定为‘control’模式并运行仿真场景。在场景参数中打开“HDS Reactor”选项卡并查看以下内容：

尽管在子控制器HDS Reactor后改变SULPHUR设定范围这一项被设置为非活动的，由于SULPHUR IN在减小的缘故，通过子控制器Blend HDS，SULPHUR依旧被控制在新的设定范围内。
从PCTP 2007后，在设计控制器时，用户可以为每个子控制器配置行为。要这样做的话，请打开控制器“HDS_Reactor_local”，并进入“Sub Controller Behavior Definition（子控制器行为定义）”节点。

你会发现SULPHUR被设置为“Local”，这表示只有当子控制器HDS Reactor处于active（活动）状态时CV才受控制。在“Controller/Mode Selection（控制器/模式选择）”节点选择该量可以轻松地模拟这一点。

仿真曲线显示SULPHUR将保持不变，这意味着由于未激活的子控制器HDS Reactor的缘故SULPHUR是没有被控制的。
用于控制的子控制器要点
你可以定义一个作为控制要点的控制器。打开控制器“HDS_Reactor_Essential”，并进入“Sub Controller Behavior Definition（子控制器行为定义）”节点。检查子控制器HDS Reactor处于控制要点状态。你可以通过选择“Reactor Essential”场景来仿真这个控制器。

因为在第90步时子控制器HDS Reactor被设置为inactive（非激活的），在90步后控制器状态变为Standby（挂起）。
优化关键子控制器
你可以将一个控制器定义为关键优化。打开控制器 “HDS_Reactor_Critical”，并进入“Sub Controller Behavior Definition（子控制器行为定义）”节点。检查子控制器HDS Reactor是处于关键优化状态。你可以通过选择“Reactor Critical”场景来模拟这个控制器。

因为在场景中的第90步子控制器HDS Reactor被设定为非激活，90步后控制器状态由Optimize（优化）切换到Control。

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原文：
Base Case
Open the Simulation node and select “Base Case” scenario. Double check that “HDS_Base” is selected for the Controller. “Base Case” scenario maximizes the feed and keeps the level at 50.
From the plot the user can see that the Feed is maximized to a value of 3185.59 while the level is controlled at setpoint (50).
** Sub-controller inactive**
Select scenario “Sub-controller inactive” and choose the HDS_Base controller. Run the simulation scenario with the controller in ‘control’ mode. Open “HDS Reactor” tab in the scenario parameters and review the following:
Although the setrange for SULPHUR changes after sub-controller HDS Reactor is set inactive, SULPHUR is still controlled within the new setrange by sub-controller Blend HDS because SULPHUR IN is decreased.
Since PCTP 2007, the user has the ability to configure the behavior for each sub-controller when you are designing the controller. To do this, open the controller “HDS_Reactor_local”, and go to “Sub Controller Behavior Definition” node.
You will find SULPHUR is set to “Local”, which indicates this CV is controlled only when sub-controller HDS Reactor is active. Selecting this quantity in the “Controller/Mode Selection” node can easily simulate this.
The simulation plot shows SULPHUR stays unchanged meaning that SULPHUR is not controlled due to an inactive sub-controller HDS Reactor.
**Sub-controller essential for control **
You can define a controller as essential for control. Open controller “HDS_Reactor_Essential”, and go to “Sub Controller Behavior Definition” node. Sub-controller HDS Reactor is checked for Essential for Control. You simulate this controller by selecting scenario “Reactor Essential”.
Sub-controller critical for optimization
You can define a controller as critical for optimization. Open controller “HDS_Reactor_Critical”, and go to “Sub Controller Behavior Definition” node. Sub-controller HDS Reactor is checked for Critical for Optimization. You simulate this controller by selecting scenario “Reactor Critical”.
The controller status becomes Standby after step 90 because sub-controller HDS Reactor is set inactive at step 90 in the scenario.
The controller status switches from Optimize to Control after step 90 because sub-controller HDS Reactor is set inactive at step 90 in the scenario.

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2016.6.12